spiral.imperial.ac.uk€¦ · -2-ABSTRACT A study of the biology and control of the dermestid beetle, Anthsizmi* Mroczk., recently introduced into Britain and now a serious pest in

To V icki

BIOLOGY AND CONTROL OF AWTHRENUS SARNICUS MROCZK., (COLEOPTERA: DERMESTIDAE)

by

Nigel James Armes B.Sc.(Lond.) A.R.C.S.

A thesis submitted for the degree of Doctor of Philosophy of the University of London and for

the Diploma of Membership of the Imperial College.

Imperial College at Silwood Park Ashurst Lodge

Ascot Berkshire

July 1985

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ABSTRACT

A study of the biology and control of the dermestid beetle, Anthsizmi*

Mroczk., recently introduced into Britain and now a serious pest in museums and a widespread domestic pest in the London area, is described.

Field studies involved determining the natural habitats and distribution of this pest in the U.K., and extensive trapping experiments were undertaken at the British Museum (Natural History) to determine its seasonal activity in indoor and outdoor environments.

Development of life stages were studied in a range of constant temperature, humidity and photoperiodic conditions and results compared with that of a native species, Anth.tiznu.6 uca6cl4cL (L.). Experiments in naturally fluctuating conditions in the laboratory showed that larval diapause development was induced by changes in photoperiod, but in outdoor conditions in a pigeon loft, where temperature fluctuations were more extreme, there was a possible interaction between photoperiodic and thermal effects on diapause development. The effects of adult feeding on fecundity, fertility and oviposition cycle were investigated. Dissection of laboratory reared beetles revealed that the physiological age of females could be identified from the stage of ovarian development and extent of the fat body. Dissection of field collected beetles showed that beetles do not become flight active until they have oviposited at least one batch of eggs, and many flew into the museum after feeding on the pollen of flowers.

The presence of a female sex pheromone and daily rhythmicity of calling behaviour in a 16:8 LD photoperiod were identified. The phototactic response of adult beetles was investigated using light- dark choice chambers, beetles became increasingly photopositive with age, and the change in response was to some extent dependant upon sex and mating condition. The attractancy of potential food odours and repellency of insecticidal vapours to adults and larvae were determined using a modified venturi-type olfactometer. Larval humidity discrimination was determined using choice chambers,

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generally larvae 'preferred' the lower of any pair of humidities offerred.

A range of commercially available insecticides of low mammalian toxicity were screened for potential use in museums, and their efficacy compared with traditionally used chemicals. The persistence of fumigant and/or contact activities of these insecticides were determined on various surfaces by bioassay and results discussed in relation to the physical properties of pesticides. Persistence of insecticides effective in the vapour phase were tested by bioassay in wooden boxes simulating museum storage conditions. Trials were conducted at the BM(NH) and in the laboratory with three candidate insecticides and their feasibility for use in museums discussed in relation to formulation, efficacy and mammalian toxicity.

Strategies for pest control in museums using environmental and chemical controls are critically evaluated in relation to the results of the present investigation, current practices and available literature .

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ACKNOWLEDGEMENTS

I should like to express my sincere thanks to my supervisor Dr. D.J. Galley for his guidance and support during the course of this study.

Drs. V.K. Brown and J.N. Brady acted as advisors to the project and their suggestions and assistance are very much appreciated. Drs. T. Ludlow and S. Young gave invaluable advice on computing and statistical problems.

I am grateful to Professor M.J. Way for the opportunity to pursue this study at the Imperial College Field Station.

Numerous staff at the British Museum (Natural History) provided assistane in many guises, but I am especially indebted to Dr.L.A. Mound who instigated this study and showed continued enthusiasm throughout its course, and to Mrs. E.R. Peacock and Mr. L. Rogers who co-ordinated much of the pest monitoring operations at the museum and provided interesting and helpful discussion during my visits. These studies were made possible through the award of a research bursary provided by the Trustees of the British Museum (Natural History), for which I am deeply grateful.

Finally I should like to thank my wife, Vicki, for her support and encouragement, without whose commitment and assistance much of this work would not have been possible.

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TABLE OF CONTENTS

PageTitle page ........................ .......... 1Abstract ..................................... 2Acknowledgements............................... 4Table of Contents ............................ 5List of T a b l e s ................................ 9List of Figures................................ 12List of P l a t e s ................................ 14PART I: BIOLOGICAL STUDIES...................... 15

1.1 Introduction.................................... 151.1.1 General........................................ 151.1.2 Status and habits of A.4a.tiru,c.u.4.....................161.1.3 Pest status of A n t h t ie jw *....................... 181.1.4 Trapping experiments ............................ 201.1.5 Ovarian development and age-grading studies •• • • 211.2 Materials and Methods........................... 29

1.2.1 Habitat surveys................................ 291.2.2 Outdoor activities of adults ................... 291.2.3 Window trapping................................ 311.2.4 Indoor light trapping ........................... 321.2.5 Culture methods................................ 35

(i) Origins of stock............................ 35(ii) Media..................................... 35(iii) Culturing procedures ...................... 36(iv) Rearing conditions ....................... 36(v) Control of opportunist pests .............. 37

1.2.6 Control of physical environments .............. 371.2.7 Egg development................................ 391.2.8 Larval development - General ................... 401.2.9 Larval development in constant conditions............411.2.10 Larval development in naturally fluctuating . . . . 41

conditions in a pigeon loft1.2.11 Larval development in fluctuating conditions • • • • 44

in the laboratory1.2.12 Some effects of photoperiod on larval .......... 44

development1.2.13 Effects of larval diet on development .......... 451.2.14 Pupal and quiescent adult stages .............. 46

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1 .2 .1 5 E f f e c t s o f la r v a l re a r in g c o n d it io n s on a d u lt ..................... 46emergence w e ig h t

1 .2 .1 6 E f f e c t s o f tem peratu re on a d u lt l i f e a n d ................................46o v ip o s it io n

1 .2 .1 7 E f f e c t s o f a d u lt d ie t on le n g th o f l i f e , fe c u n d ity . • 47 and o v ip o s it io n

1 .2 .1 8 O va rian developm ent ...................................................................................... 48

1 .2 .1 9 D is s e c t io n o f f ie ld c o lle c te d b e e tle s ...................................... 49

1 .3 R e s u l t s .................................................................................................................................50

1 .3 .1 H a b ita t s u r v e y s .........................................................................................................50

1 .3 .2 Outdoor a c t iv i t ie s o f a d u lt s .......................................................................... 51

1 .3 .3 Window t r a p p in g .........................................................................................................54

1 . 3 .4 In do o r l ig h t tra p p in g ...................................................................................... 61

1 .3 .5 Egg d e v e lo p m e n t ......................................................... ..................................66

1 .3 .6 L a r v a l developm ent in co n sta n t c o n d it io n s .....................................66

1 .3 .7 L a r v a l developm ent in n a tu r a lly f lu c tu a t in g . . . . 79c o n d itio n s in a p igeon l o f t

1 . 3 .8 L a r v a l developm ent in f lu c tu a t in g c o n d itio n s . . . . 82in th e la b o ra to ry

1 .3 .9 Some e f f e c t s o f pho to perio d on la r v a l developm ent . . 93

1 .3 .1 0 E f f e c t s o f la r v a l d ie t on developm ent ....................................... 93

1 .3 .1 1 P up a l and q u ie sc e n t a d u lt s ta g e s ....................................................... 97

1 .3 .1 2 E f f e c t s o f la r v a l re a r in g c o n d it io n s on a d u lt . • • • 97emergence w e ig h t

1 .3 .1 3 E f f e c t s o f tem peratu re on a d u lt l i f e a n d ............................... 101o v ip o s it io n

1 .3 .1 4 E f f e c t s o f a d u lt d ie t on le n g th o f l i f e , ............................... 104fe c u n d ity and o v ip o s it io n

1 .3 .1 5 Anatomy o f th e fem ale re p ro d u c tiv e s y s t e m ..............................117

1 .3 .1 6 O va rian developm ent ........................................................................................122

1 .3 .1 7 D is s e c t io n o f f ie ld c o lle c te d b e e t le s ........................................... 128

1 .4 D i s c u s s io n ................................................................................................................... 133

1 .4 .1 Eco lo g y o f A .4 a ^ n X c t t4 .......................................... ................................. 133

1 . 4 .2 Egg d e v e lo p m e n t ..................................................................................................... 135

1 . 4 . 3 L a r v a l d eve lo p m en t.................................................................................................. 135

1 . 4 .4 Fe cu n d ity and o v ip o s i t io n .......................................................................... 142

1 . 4 . 5 In t r in s ic r a te o f p o p u la tio n in c re a s e ........................................ 144

1 . 4 .6 O va rian d e v e lo p m e n t ........................................................................................... 146

1 .4 .7 D is s e c t io n o f f ie ld c o lle c te d b e e tle s ........................................ 147

1 .5 Summary . ........................................................................................................................ 150

Page

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PART II: BEHAVIOUR STUDIES........................ 1522.1 Introduction...................................... 152

2.1.1 Sex pheromone releasing behavior....................1522.1.2 Olfaction experiments ........................... 1532.1.3 Phototactic response of adults ................... 1542.1.4 Larval humidity discrimination.....................1542.2 Materials and Methods ............................ 155

2.2.1 Sex pheromone releasing behaviour ................. 1552.2.2 Olfaction experiments .. 1572.2.3 Phototactic response of adult beetles ............ 1602.2.4 Larval humidity discrimination.....................1612.3 Results ....... 163

2.3.1 Sex pheromone releasing behaviour ..................1632.3.2 Olfaction experiments ............................ 1662.3.3 Phototactic response of adult beetles ............ 1662.3.4 Larval humidity discrimination.....................1702.4 Discussion....................................... 175

2.4.1 Sex pheromone releasing behaviour ................. 1752.4.2 Olfaction experiments ............................ 1772.4.3 Phototactic response of adult beetles .. .. .. .. 1792.4.4 Larval humidity discrimination.....................1802.5 Summary.......................................... 182

PART III: CHEMICAL CONTROL STUDIES................. 1833.1 Introduction...................................... 1833.2 Materials and Methods ............................ 186

3.2.1 Culturing procedures for bioassays................. 1863.2.2 Insecticides...................................... 1863.2.3 Persistence of fumigant and contact activities .. .. 189

of pesticides3.2.4 Persistence of insecticide deposits on 'Plastazote' .. 1913.2.5 Relative susceptibilities of Anthêjiu^ develop- .. .. 191

mental stages to the contact and fumigantactivities of insecticides

3.2.6 Persistence of fumigant activity of insecticides . .. 192in wooden boxes

3.2.7 Field evaluation of some candidate insecticides . .. 1943.3 Results.........................................197

3.3.1 Persistence of fumigant and contact activities .. .. 197 of pesticides

3.3.2 Persistence of insecticide deposits on 'Plastazote' .. 203

Page

3.3.3 Relative susceptibilities of An£k>i£mi6 develop- . .. 203mental stages to the contact and fumigantactivities of insecticides

3.3.4 Persistence of fumigant activity of insecticides . .. 210in wooden boxes

3.3.5 Field evaluation of some candidate insecticides . .. 2193.4 Discussion....................................... 2253.5 Summary.......................................... 238

PART IV: STRATEGIES FOR PEST CONTROL IN MUSEUMS . ..2404.1 Chemical control ................................2404.2 Non-chemical control............................... 244

(i) Raised temperature............................ 244(ii) Low temperature............................... 245(iii) Modified atmospheres ....................... 245

4.3 Specimen storage systems .......................... 2464.4 Building hygiene...................................2464.5 Buliding design...................................2474.6 Safety........................................... 2484.7 Education and training............................ 2484.8 Establishment of a body responsible f o r ............ 249

conservation of natural history collectionsREFERENCES....................................... 251APPENDIX I: GLIM model results.....................258APPENDIX II: Temperature and day length records .. .. 260APPENDIX III: Effects of larval diet ............ 262APPENDIX IV: Dissection results for field ......... 263

collected beetlesAPPENDIX V: Parameters of probit regression ........ 268

equations

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Page

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LIST OF TABLES

PART I: BIOLOGICAL STUDIESPage

1.1 Saturated salt solutions used to maintain relative....... 38humidities at different temperatures

1.2 Temperature-humidity combinations used in larval ........ 42development experiments

1.3 Composition of meridic diet used for rearing ............ 43k . 6a>inXxLu.6 larvae

1.4 Total numbers of Antlw.tnu.4 spp., caught on outdoor .. sticky-traps during the 3 year study

1.5 Numbers of A. -ia/tnLcu.* caught on flower-heads of plant .. species in the grounds of the BM(NH) between 1982-84

1.6 1982-84 weekly captures of k.6afiYUjc.ii6 at window sticky . traps in the General Herbarium

1.7 1983-84 weekly captures of kn£hn.ojtu4 spp., at window sticky-traps in the Entomology Building

1.8 Duration of the egg stage and percentage hatch of eggs .. under different temperature-humidity conditions for eggs laid at 20°C, 70%rh and in the conditions in which they hatched

1.9 Proportion of larvae pupating in 1 or 2 years when introduced as 1 st instar larvae to outdoor conditions in a pigeon loft and exposed to natural photoperiodor constant dark for the duration of larval development

1.10 Development of A. 6an.Yuuc.iL6 in fluctuating conditions in the laboratory

1.11 Larval developmental periods and percentage survival on various diets, together with their growth indices

1.12 Effects of temperature and humidity on the duration and mortality of the pupal and quiescent adult stages

1.13 Mean emergence weights of adult beetles derived from larvae reared on standard medium and meridic diet

1.14 Effects of temperature on adult life and oviposition at 70% rh in constant dark

.. 51

.. 57

.. 58

.. 62

.. 67

.. 81

.. 87

.. 96

.. 98

.. 101

.. 103

1.15 Emergence weights of male and female beetles allocated . .. 105to each diet and the pooled data for experiments at20 & 25°C.

1.16 Effects of adult diet on longevity, fecundity and ....... 106fertility at 25°C, 70%rh

1.17 Frequency of the start of oviposition at 20 & 25°C, .. .. 10870% rh in paired beetles fed on different diets

1.18 Oviposition and longevity of virgin females at 20 & .. .. Ill25°C, 70% rh, fed on different diets

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1.19 Effects of adult diet on longevity, fecundity and fertility at 20°C, 70% rh

1.20 Stages of ovarian development, mating condition and size of fat body for mated and virgin females of different age classes, kept at 20°C, 70% rh, 16:8LD photoperiod

1.21 Summary of dissection data for A.-4ol>i y u L c. u.6 beetles collected at four sites at the BM(NH) during the 1983 field season

PART II: BEHAVIOUR STUDIES

2.1 Total percentages of males responding to assay disks2.2 Change in response of number of females calling at

periods after emergence from the last larval skin2.3 Larval humidity discrimination data. Tables of

percentage means of larvae in high humidity, their effective standard errors and analysis of variance results

PART III: CHEMICAL CONTROL STUDIES

3.1 Estimated LC™ values for early instar A.^LavLpe* larvae exposea to the fumigant and contact activity of residual surface deposits of insecticides

3.2 Estimated rates of decay of insecticidal activity at 25°C based on bioassay with A. filavjLpz* for deposits applied to glass and filter paper surfaces

3.3 Estimated LC™ values for early instar A. filcLvipeA larvae exposea to the fumigant and contact activity of residual deposits of insecticides on Plastazote

3.4 Estimated rates of decay of insecticidal activity at 25°C based on bioassay with A. f.ai/Xpe.4 larvae for deposits applied to Plastazote

3.5 Estimated potencies relative to the adult stage, of the fumigant and contact activities of insecticides

3.6 Comparative susceptibilities to insecticides of larvae .. of the different Antk^mu6 species tested

3.7 The percentage mortalities of A l a r v a e exposed to the fumigant activity of residual deposits of insecticides in wooden boxes for 48 hours

3.8 The percentage mortalities of A.^LavLpe* larvae held in fly puparia and exposed to the fumigant activity of residual deposits of insecticides in wooden boxes for 48 hours

Page .. 114

.. 127

.. 129

.. 164

.. 164

.. 171

.. 198

.. 202

.. 206

.. 207

.. 209

.. 211

.. 215

.. 217

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3 .9 E s tim a te d LC^q v a lu e s fo r A . f i la v jL p z A la rv a e exposed to th e fum igant a c t iv i t y o f r e s id u a l d e p o s its o f in s e c t ic id e s in wooden boxes

3 .1 0 E stim a te d LC^q v a lu e s fo r A .^ ta .\}Ju pc6 la rv a e h e ld in f l y p u p a ria and exposed to the fum igant a c t iv i t y o f r e s id u a l d e p o s its o f in s e c t ic id e s in wooden boxes

3 .1 1 E stim a te d ra te s o f lo s s o f in s e c t ic id a l a c t iv i t y in wooden boxes a t 25°C based on s ig n if ic a n t s t r a ig h t l in e r e la t io n s h ip s between fum igant LC 50 and tim e a f t e r tre a tm e n t

3 .1 2 E f f e c t s o f th e fum igant a c t iv i t y o f ag ing V a p o rth rin m othproofing s t r ip s to e a r ly in s t a r A . l la .\ jJ ip c 6 la rv a e in in s e c t s to ra g e boxes

3 .1 3 I n i t i a l d e p o s its in g la s s v ia ls re q u ire d to k i l l 50% o f e a r ly in s t a r A . 6a.siyu.CLL6 la rv a e by fum ig ant and c o n ta c t a c t io n a f t e r 4 m onths, based on 24 h r exposure a t 25°C

PART IV : STRATEGIES FOR PEST CONTROL IN MUSEUMS

4 .1 Summary o f a p p lic a t io n r a t e s , e f fe c t iv e l i f e o ftre a tm e n ts and h aza rd s fo r f iv e in s e c t ic id e s te s te d fo r th e p ro te c t io n o f in s e c t c o lle c t io n d raw ers a g a in s t damage by e a r ly in s t a r An t Iv iz n u A la rv a e

Page

.. 220

.. 221

.. 222

. . 224

. . 229

.. 241

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L IS T OF F IG U R E S

Page

1 .1 In te rc e p t io n s t ic k y - t r a p s used to sam ple k , 4dn.YiLQ.n4 ..................... 33a t the B r i t i s h Museum (N a tu ra l H is to ry )

1 .2 W eekly numbers o f a d u lts o f th re e AY i t h n . z n u . 4 sp e c ie s ..................... 52cau g h t on w h ite and y e llo w co lo u red m o d ified aph id in te rc e p t io n tra p s in th e grounds o f the BM(NH) in1982 , w ith w eek ly mean tem peratu res d u rin g the tra p p in g p e rio d

1 .3 W eekly numbers o f a d u lts o f th re e k n t k n . z y i u . 4 sp e c ie s ..................... 53cau g h t on the w h ite d is h tra p s in th e grounds o f theBM(NH) in 1982 , w ith w eek ly mean tem p eratu res d u rin g th e tra p p in g p e rio d

1 .4 1983-84 ca p tu re s o f k n t h n . z . m i 4 sp e c ie s on w h ite co lo u re d . . . . 55in te rc e p t io n s t ic k y - t r a p s in the grounds o f the BM(NH)and w eek ly maximum and minimum outdoor tem peratu res

1 .5 G e n e ra l H erbarium window tra p c a p tu re s o f A . 4 d n .n L c .a 4 ..................... 60

1 .6 1983-84 Entom ology B u ild in g window tra p ca p tu re s o f ..................... 64A. <4dn.YlLc.U4

1 .7 1982 w eek ly ca p tu re s o f k , 4 d n . Y i L c . u 4 in th e c y lin d e r ..................... 65l ig h t tra p s lo c a te d in th e Zoology s to re room

1 .8 E f f e c t o f tem peratu re on the d u ra tio n o f th e egg ..................... 68in c u b a tio n p e rio d

1 .9 F req u en cy d is t r ib u t io n s o f p u p atio n tim es fo r k . 4 u n . Y i L c . u 4 . . . 69la rv a e re a re d under d if fe r e n t co n sta n t en v iro n m en ta l c o n d it io n s

1 .1 0 The e f fe c t o f tem peratu re and h u m id ity on the d u ra tio n . . . . 71o f th e la r v a l p e r io d , number o f la r v a l m ou lts andp e rcen tag e o f la rv a e s u rv iv in g to p u p atio n

1 .1 1 D u ra tio n s o f la r v a l in s t a r s and numbers o f la rv a e ..................... 75rem a in in g in each in s t a r fo r la rv a e re a re d inc o n s ta n t tem p era tu re -h u m id ity c o n d it io n s

1 .1 2 P u p a tio n d a te s o f la rv a e re a re d under outdoor c o n d it io n s . . 80in a p igeon lo f t , in tro d u ce d as 1 s t in s t a r la rv a e in to the e xp e rim e n ta l c o n d it io n s a t m onthly in t e r v a ls

1 .1 3 D u ra tio n s o f la r v a l in s t a r s and numbers o f la rv a e ..................... 83rem a in in g in each in s t a r fo r la rv a e re a re d inf lu c tu a t in g c o n d it io n s in a p igeon l o f t , e ith e r in n a tu ra l pho to perio d o r co n sta n t d a rk

1 .1 4 P u p a tio n fre q u e n c ie s o f k . 4 u n . Y i L c . u 4 re a re d in the . . . . 88la b o ra to ry under f lu c tu a t in g tem peratu re and h u m id ity c o n d it io n s

1 .1 5 D u ra tio n s o f la r v a l in s t a r s and numbers o f la rv a e ..................... 89rem a in in g in each in s t a r fo r la rv a e re a re d inf lu c tu a t in g c o n d it io n s in th e la b o ra to ry , e ith e r in n a tu ra l pho to p erio d o r co n sta n t d a rk

PART I : BIOLOGICAL STUDIES

1 .1 6 E f f e c t s o f c o n sta n t d a rk and a reg im e o f in c r e a s in g ..................... 94w eek ly p h o to perio d on the d u ra tio n o f th e la r v a lp e rio d and d u ra tio n and number o f la r v a l in s t a r s

1 .1 7 E f f e c t s o f la r v a l d ie t on the p u p atio n fre q u e n c ie s o f . . . . 95A . 6CLn.YuLc.ULti a t 20 °C , 70% r h , 16 :8LD photoperiod

1 .1 8 E f f e c t o f tem peratu re on the d u ra tio n s o f the p u p a l ..................... 99and q u ie sc e n t a d u lt p e rio d s

1 .1 9 E f f e c t o f tem peratu re and h u m id ity d u rin g la r v a l ............................. 100developm ent on a d u lt em ergence w e ig h t

1 .2 0 Mean emergence w e ig h ts o f b e e t le s d e riv e d from la rv a e • • • • 102re a re d on d if f e r e n t d ie t s a t 2 0 °C , 70% rh

1 .2 1 Mean d a ily o v ip o s it io n r a te and s u rv iv o rs h ip o f p a ir s •• •• 109o f a d u lt b e e t le s fed on d if f e r e n t d ie t s a t 2 5 °C , 70%rh in a 16:8LD pho to perio d

1 .2 2 Mean d a ily o v ip o s it io n r a te o f v ir g in fem ales fed on . . . . 112d if f e r e n t d ie t s a t 25 °C , 70% rh

1 .2 3 Mean d a ily o v ip o s it io n r a te and s u rv iv o rs h ip o f p a ir s •• •• 115o f a d u lt b e e t le s fe d on d if f e r e n t d ie t s a t 20 °C , 70%rh in a . l 6 : 8LD pho to perio d

1 .2 4 Mean d a ily o v ip o s it io n r a te o f v ir g in fem ales fed on . . . . 118d if f e r e n t d ie t s a t 2 0 °C , 70% rh

1 .2 5 D iagram o f the fem ale re p ro d u c tiv e system o f A .6 a t i r u ic a 6 • •• 1203 days a f t e r em ergence from th e la s t la r v a l s k in

1 .2 6 C h ro n o lo g ic a l s ta g e s o f o v a ria n developm ent in ............................. 123A . 6 cl>l v u j c u .6 a t 2 0 °C , 65% rh

1 .2 7 Len g th s o f o v a ry , o v a r io le and p ro x im a l o o cyte d u r in g .................. 125o v a ria n developm ent a t 20 °C , 65% rh

1 .2 8 H isto g ram s o f numbers o f m ale and fem ale A.6cLtivuLc.u.6 •• •• 130caug ht each week a t the th re e tra p s it e s a t th e BM(NH)in 1983

1 .2 9 In t r in s ic ra te s o f in c re a s e p e r 28 day p e rio d fo r ..................... 145A . 6a.tLruLc.u6 a t d if f e r e n t tem p eratu res under co n sta n t c o n d it io n s

PART I I : BEHAVIOUR STUDIES

2 .1 D iagram o f d is k b io a ssa y te ch n iq u e to c o lle c t se x ..................... 156pheromone from fem ale A . 6atinJLcu.6

2 .2 D iagram o f m o d ifie d v e n tu r i- ty p e o lfa c to m e te r ap p aratu s • •• 158

2 .3 A lte rn a t iv e chamber used in t e s t s o f h u m id ity ............................. 158d is c r im in a t io n

2 .4 C a llin g p o stu re o f fem ale A .6ativuLc.u .6 ....................................................... 163

2 .5 D a ily p e r io d ic it y o f fem ale c a l l in g b eh av io u r a n d .......................... 165m ale resp o n se to d is k s exposed to fem ales

2 .6 C on tingency c o e f f ic ie n t s o f a t t ra c ta n c y and r e p e ll- ..................... 167ency o f A .6 a sivu Lcu .6 to d if fe r e n t odour so u rces

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2 .7 P h o to ta c t ic resp o n se o f a d u lt b e e t le s . E f fe c t s o f ..................... 168a g e , se x and m ating c o n d itio n on the resp o n se tol ig h t

2 .8 L a r v a l h u m id ity d is c r im in a t io n ............................................................... 172

PART I I I : CHEMICAL CONTROL STUDIES

3 .1 P lo ts o f vapour p re ssu re a g a in s t r a te o f decay o f ............................. 204in s e c t ic id a l a c t iv i t y

3 .2 P lo ts o f vapour p re ssu re a g a in s t r a te o f decay o f ............................. 208in s e c t ic id a l a c t iv i t y fo r d e p o s its on P la s ta z o tes u rfa c e s

3 .3 P o te n c ie s o f th e c o n ta c t and fum ig ant a c t iv i t ie s o f .......................... 212th e t e s t in s e c t ic id e s r e la t iv e to the in s e c t ic id a lt o x ic it y o f n a p h th a le n e , fo r th e d if fe r e n t l i f e - s ta g e s o f th e th re e kYithuzyiu .^ sp e c ie s

L IS T OF P LA T E S

P la te I S tag es in the l i f e - c y c le o f A .4a>injLc,u.6 ............................. 23

(a ) A c t iv e a d u lt(b ) Eggs( c ) E a r ly in s t a r la rv a e

P la te I I S tag es in th e l i f e - c y c le o f A ............................. 25

(a ) L a te in s t a r la r v a(b ) Pupa( c ) Q u ie scen t a d u lt in la s t la r v a l s k in

P la te I I I S e xu a l d im orphism in A .6 a n .n jLc .a 6 ............................. 27

V e n tra l v ie w o f m ale and fem ale pupae removed from la s t la r v a l s k in to show th e g e n ita l p a p illa e

Page

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PART I

B I O L O G I C A L STUDIES

1 .1 In tro d u c t io n

1 .1 .1 G e n e ra l

The A n th re n in ae a re co n sid e re d to be the most s u c c e s s fu l and s p e c ia l

is e d o f the D erm estidae (H in to n , 1 9 4 5 ), w ith o ver 83 known sp e c ie s

m o stly from the P a la e a r c t ic re g io n (M ro czko w sk i, 1 9 6 8 ). Many o f th ese

a re ,o f c o n s id e ra b le econom ic im portance and a re lo o s e ly re fe r re d to

a s 'c a rp e t b e e t le s ' because o f th e ir p re d ile c t io n fo r p ro cessed an im a l

p ro d u cts such as w o o llen fa b r ic s and o th e r d rie d p ro te in a ce o u s

m a te r ia ls .

L a rv a e o f t h is su b fa m ily a re named 'w o o lly b e a rs ' because o f th e

abundance o f long se ta e on t h e ir b o d ies (P a rk in & W oodro ffe , 1 9 6 1 ).

Th ree d is t in c t typ es o f body se ta e a re commonly found in s e v e ra l

genera o f the A n th re n in a e , nam ely , h a s t is e ta e , sp ic a se ta e and

n u d ise ta e (B e a l, 1 9 6 0 ). The h a s t is e ta e w h ich a re found a lo ng th e

m arg ins o f th e 5 th , 6th and 7 th abdom inal segm ents a re p e c u lia r

f i l i f o r m , barbed and sp ea r tip p e d se ta e w h ich a re s t r u c t u r a lly the

most co m p lica ted known amongst the in s e c ts and a re co n sid e re d to be

a d e fe n s iv e mechanism a g a in s t p re d a to rs and p a ra s ite s (N u ttin g &

S p a n g le r, 1969; Ma e X a t . , 1 9 7 8 ). I t i s the la rv a e w h ich a re th e

damaging s ta g e s , th e a d u lts o n ly feed outdoors on the p o lle n and

n e c ta r o f f lo w e rs , a lth o u g h t h is i s n o t e s s e n t ia l fo r re p ro d u c tio n

(G r is w o ld , 1941; B la k e , 1 9 6 1 ). N ests o f b ird s and mammals a re the

two most im p o rtan t r e s e r v o ir s fo r dom estic in fe s t a t io n s , and a

c o n s id e ra b le number o f sp e c ie s have been reco rd ed in th ese s i t u

a t io n s , where the la rv a e feed on fe a th e rs , h a i r , fragm ents o f food

d e b ris and dead in s e c ts (H in to n , 1945; W oodro ffe , 1953; W oodroffe

& So u th g a te , 1 9 5 4 ). Some b reed n ea r s p id e rs ' webs w here th ey feed

on rem nants o f in s e c ts o r even on the eggs o f sp id e rs (H in to n , 1 9 4 3 ),

w h ile o th e rs l i v e in the n e s ts o f wasps and bees fe ed in g on dead

in s e c ts and to some e x te n t honey and p o lle n (H in to n , 1 9 4 5 ). The

o r ig in a l n a tu ra l d ie t o f d e rm estid la rv a e appears to have been d ry

p ro te in a ce o u s m a te r ia ls o f an im a l o r ig in , and indeed they have a

d ig e s t iv e enzyme system cap ab le o f d ig e s tin g k e r a t in s . A n th .K e .n a 6 in

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p a r t ic u la r a re adapted to fe ed in g on m a te r ia ls o f v e ry low m o istu re

co n te n t and th is i s th e m ain reaso n a t t r ib u te d to t h e ir su cce ss as

p e s ts o f p ro cessed an im a l p ro d u cts such as w o o llen fa b r ic s w h ich may

have a m o istu re co n te n t o f as l i t t l e as 11-12% (B u s v in e , 1 9 6 6 ).

The f i r s t p u b lish e d re co rd o f AYith.fic.YLu4 sp e c ie s (C o le o p te ra ,

D erm estid ae ) damaging museum specim ens was by L in n aeu s (1 7 6 7 ), who

found A . m u 4 C . o f i u m ( L . ) a tta c k in g d r ie d in s e c t c o lle c t io n s . A lthough

c a lle d th e 'Museum b e e t le ', i t i s n o t as common in th e se s itu a t io n s

as A . v e m . b a 4 c L ( L . ) , th e 'v a r ie d c a rp e t b e e t le ', w h ich i s a cosmo

p o lita n sp e c ie s and to d a te i s the most im p o rtan t p e s t o f d r ie d

an im a l c o lle c t io n s in tem perate re g io n s . I t was f i r s t reco rd ed dam

ag in g in s e c t c o lle c t io n s in Germany by E ric h so n (1 8 4 6 ), and s in c e

then th e re have been numerous re fe re n c e s to i t s damage to museum

specim ens (se e H in to n , 1 9 4 5 ). Th e re a re o n ly th re e A Y Lth fizn u 4 sp e c ie s

in d ig en o u s to B r it a in - A . \ j v i b c i 4 c X ( L . ) , A . m u 4 < i o f i u m ( L . ) , and A . 6 u . 6 c . u 6 O liv . Fo ur o th e rs a re o c c a s io n a lly in tro d u ce d - A . l l a v L p o . 4 LeC o n te ,

A . p J L m p J b i c Z Z a c . F a b ., A . 4 c f i o p k u t a f L L a e . ( L . ) , and A . c . o L o n . < x t u 4 R e it t e r ,

b u t none o f th ese have become e s ta b lis h e d h e re (W o o d ro ffe , 1 9 6 7 ).

1 .1 .2 S ta tu s and h a b its o f A . 4 a f i Y i L c . u 4

In J u ly 1961 la rv a e o f an unknown A Y \ t h n . c n u 4 sp e c ie s w ere re c e iv e d by

M r. R . Edwards o f R e n to k il L t d . , from a dom estic in fe s t a t io n in

S t .M a r t in s , G u e rn sey , Channel Is la n d s . These la rv a e w ere re a re d on

a d ie t o f w o o llen m a te r ia l, fish m e a l and y e a s t a t 25-27°C & 40-50%

r e la t iv e h u m id ity ( r . h . ) . The a d u lts th a t emerged co u ld n o t be

id e n t if ie d from th e l i t e r a t u r e and in 1962 D r. M acie j M roczkow ski

a t th e P o lis h Acadamy o f S c ie n c e s , W arsaw , d e sc rib e d i t a s a new

s p e c ie s , a s s ig n in g i t the name AYith.fi2.YLu4 4 c m . Y i L c . u 4 , a f t e r 'S a rn ia '

th e Roman name fo r th e Is la n d o f G uernsey (M ro czko w sk i, 1 9 6 2 ).

The n e x t re c o rd was from London in May 1963 , and up to 1968 th e re

w ere a t le a s t s ix co n firm ed re co rd s o f in fe s t a t io n s around th e S.W .

p o s ta l d is t r ic t s o f London, and one re c o rd from a m il it a r y camp on

S a lis b u ry P la in , W ilt s h ir e (Ed w ard s, 1 9 6 9 ). Edwards co n s id e re d th a t

i t was w id e ly p re se n t in w est London and p o s s ib ly o th e r a re a s o f

so u th e rn Eng land w here i t was b e in g o verlo o ked by e n to m o lo g is ts .

By 1971 i t had been c o lle c te d from n in e lo c a t io n s in London

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( C o rn w e ll, 1 9 7 1 ), and the f i r s t re co rd o f th is in s e c t as a museum

p e s t was in 1973 w here la rv a e had caused c o n s id e ra b le damage to

C o le o p te ra c o lle c t io n s in the B r i t i s h Museum (N a tu ra l H is t o r y ) ,

(BM (N H )), London SW7 (P e a co ck , u n p u b lish e d ), and su b seq u en tly was

found damaging costum es in the V ic t o r ia and A lb e rt Museum, London

SW7 (H a ls te a d , 1 9 7 5 ). Up to 1984 th e re have been 33 co n firm ed

re c o rd s , ce n tre d around London, a lth o u g h more re c e n t f in d s sug gest

th a t i t i s in c re a s in g i t s d is t r ib u t io n in the U n ited Kingdom . The

o n ly fo re ig n re co rd to d a te i s from Am sterdam , N e th e rla n d s , w here

a la r v a l in fe s t a t io n was re p o rte d from a house (A non , 1 9 7 5 ). I t i s

co n sid e re d th a t t h is sp e c ie s d id n o t o r ig in a te in th e Channel

Is la n d s b u t was m ost l i k e ly im ported from abroad on com m od ities.

To d a te i t s o r ig in s and n a tu ra l h a b ita ts a re unknown.

A . 6 a f in t a u 6 may in f a c t be more abundant in the U .K . than re co rd s

tend to suggest and i s b e in g o verlo o ked o r n o t id e n t if ie d beyond

'c a rp e t b e e t le ', o r m is id e n t if ie d because o f i t s s u p e r f ic ia l ly

c lo s e resem blance to the n a t iv e A nth .fie .n u 6 s p e c ie s . The a d u lts o f

A .6 a .t in tc .u 6 resem b le A .i> e.fiba.6ct and A .m u 6 e .o fiu m , bo th o f w h ich a re

common in so u th ern En g lan d , b u t g e n e ra lly th e 'new ' sp e c ie s i s

la r g e r , more e lo n g a te and lig h t e r in c o lo u r (P la t e l a ) . The co lo u r

p a tte rn in g i s form ed from p a tch es o f b la c k , y e llo w and w h ite s c a le s

and i s v e ry v a r ia b le . Edwards (1 9 6 9 ) i l lu s t r a t e s a d a rk and a l ig h t

fo rm , b u t p a tte rn s from a lm o st com plete g re y -w h ite to b la c k have

been observed in th e p re se n t s tu d y . G e n e ra lly b la c k s c a le s a re

d is t in c t in the m id - lin e o f th e e ly t r a where they form a ro u g h ly

W -shaped p a tte rn e xte n d in g la t e r a l ly about h a lf-w a y a c ro ss each

e ly t ro n . The s c a le s a re b ro a d ly t r ia n g u la r in shape and a re s im ila r

to tho se o f A .m u6e.ofium and A .^ it4cu4 , b u t im m ed iate ly se p a ra te s i t

from A . v e A b a .6 c t w h ich h as e lo n g a te o v a l s c a le s . The m ost r e l ia b le

c h a ra c te r fo r se p a ra tin g a d u lts from o th e r A n th n .e jn u 6 sp e c ie s i s the

number o f an te n n a l segm ents. A .6 a f i n t c u 6 has 10-segm ented an ten n ae ,

th e o th e rs have 1 1 , 9 , 8 o r 5 segm ents. M roczkow ski (1 9 6 2 ) found

th a t m ales may have segm ents 6 & 7 p a r t ly fu se d , the antennae

ap p earin g 9-segm ented, b u t t h is t r a i t was n o t observed in th e co u rse

o f th e p re se n t in v e s t ig a t io n .

I t i s n o t p o s s ib le to se p a ra te th e la rv a e o f the n a t iv e sp e c ie s

from tho se o f A .6 a f i n t c u 6 w ith any co n fid e n ce (P la te I c & P la te I l a ) .

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W oodroffe (1 9 6 7 ) found th a t in la rg e la rv a e the second segment o f

th e antennae i s a t le a s t 3^ tim es as long as b ro ad , w h ile in the

n a t iv e sp e c ie s i t i s n o t more than 3 tim es as long a s b ro ad , a lth o u g h

t h is c h a ra c te r i s n o t co n sid e re d to be r e l ia b le (P e a co ck , p e rs . com m .).

From the in fe s t a t io n s d e sc rib e d by W oodroffe (1 9 6 7 ), la r v a l fe ed in g

h a b its appear to be v a r ie d , a lth o u g h s im ila r to th e n a t iv e A . v€A6a.4cL.

In the G uernsey in fe s t a t io n damage was to c lo th in g in cupboards in a

p r iv a te h o u se . In two in fe s t a t io n s in London f l a t s , la rv a e w ere

found in accu m u la tio n s o f f l u f f and food d e b ris in c ra c k s between

flo o rb o a rd s and b eh ind a p a n e l c o v e rin g a d isu sed e le c t r ic f i r e ,

damaging edges o f c a rp e ts and c lo th in g in a w ard robe . In th e S a lis b u ry

P la in in fe s t a t io n la rg e numbers o f la rv a e were found on a dead p igeon

b eh ind a p a n e l c o v e rin g a d isu se d f ir e p la c e and s m a lle r numbers w ere

found on f l u f f and food d e b ris beh ind p a n e ls . In museums la rv a e

h ave been re p o rte d damaging in s e c t c o lle c t io n s , s tu ffe d an im a ls and

w ool based c lo th in g . An t h t i z m i* la rv a e were found in la rg e numbers in

p igeon n e s ts and m o ist guano in h e a tin g tow ers o f th e BM(NH) in 1981.

From W o o d ro ffe 's (1 9 6 7 ) la r v a l d e s c r ip t io n th ese appeared to be

A .4 am cc .u 4 , b u t w ere k i l le d b e fo re th ey co u ld be re a re d through to

th e a d u lt sta g e and th e sp e c ie s co n firm e d .

P u p a tio n c h a r a c t e r is t ic a l ly o ccu rs w ith in the la s t la r v a l s k in

(P la t e l i b ) , and s e x u a l dim orphism o f th e g e n ita l appendages i s

ap p aren t a t t h is sta g e (H a ls te a d , 1 9 6 3 ). The g e n ita l p a p illa e o f

■ A . AOLn.YuLc.u.6 a re s im ila r to those o f A . v Z A b o L tcJ i. In th e m ale they a re

g lo b u la r and co n verg en t and in th e fe m a le , 3-segm ented, s tro n g ly

p ro tu b e re n t and n e a r ly p a r a l le l (P la t e I I I ) . When th e a d u lts emerge

from the pupa th ey rem ain q u ie sc e n t w ith in the la s t la r v a l s k in

(P la t e l i e ) . D u ring t h is p e rio d h ard en in g o f the c u t ic le and m atu

ra t io n o f the gonads ta ke s p la c e .

1 .1 .3 P e s t s ta tu s o f A n £ k > ie jw 6

W ith in f iv e y e a rs o f i t s d is c o v e ry in th e BM(NH), A .-4ativuLcu.* had

become the most s e r io u s p e s t damaging in s e c t and s tu ffe d an im a l

c o lle c t io n s in th e museum. P r io r to i t s d is c o v e ry , th e museum had

s u ffe re d o n ly sm a ll sp o ra d ic in fe s t a t io n s o f A.ve/i6a>5c.I. Such ra p id

in v a s io n s o f in tro d u ce d d erm estid s and th e app aren t e c lip s e o f the

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native species is not unusual. Hinton (1945) states that in parts of North America A . v e x b a t e . * , was overtaken by T K o g o d o jim a . vq.k 6 jlc . o I o k

(Creutz), as a serious pest of museum collections and in the collections of the Natural History Museum in Vienna both A .v Q .K b a .6 c u L and A .m u .6 Q.0K um had nearly completely been replaced by 1934 by A . c. olucol6JL c. u 6

Reitter, which was first introduced in 1910.

The early 1980's saw an alarming population explosion of A.6aKruLc.u6 in the BM(NH) and it became apparent that current pest control practises were ineffective at preventing damage to specimens. Museum staff had little knowledge on which to base control measures, only generalised comments on its habits and biology had been published (Edwards, 1969; Woodroffe & Hill, 1969), and information regarding the use and safety of pesticides in museums was scant and largely outdated (Edwards oX al., 1981). Recently Woodroffe's studies on the biology of A.6clkvu.cu6 have been published posthumously (Coombs & Woodroffe, 1983), but this work was largely unfinished and lacks sufficient replication. As most An £h.K Q Jiu .6 are pests of only minor or no economoc importance, they are a little studied group of insects. Hinton (1945) reviewed the literature up to 1943 of the known biology of eight species either indigenous or casual introductions into the U.K. Subsequently only A.vojiba.6cX and A.ta.vXjpo.6 have received much attention from biologists, the former being a cosmopolitan domestic, museum and wool and silk trade pest, and the latter an important pest of woollen materials in warm climates. The major works on the biology of A.voAba6cX are attributable to G.M. Blake, initially as a PhD thesis submitted in 1955 (Univ. of London), and continuing after this to span a period of some 20 years. Her published papers will be discussed in context with the results for A. 6olkvuxlul6 in the relevant sections below.

The aims of this thesis were to investigate the biology of A . 6 clkhX c. u 6

and more generally, some aspects of the control of insect pests in museums. From the point of view of control it is of obvious importance to determine the kinds of habitats which under natural conditions support populations of pest insects. In order to obtain more information on the pest potential of A . 6 clkyu .c. u 6 experiments were undertaken to determine its distribution, natural habitats and

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se a so n a l a c t iv i t y in the London a re a . L a b o ra to ry s tu d ie s on th e

b io lo g y o f A . 6 a n . r u i c a 6 w ere aim ed p r im a r ily a t in v e s t ig a t in g th e

e f fe c t s o f co n sta n t and f lu c tu a t in g c o n d it io n s on the d eve lo pm enta l

s ta g e s , u s in g stan d ard p ro ced u res fo r s to re d p ro d u cts in s e c t s , in

o rd e r th a t a com parison o f i t s p e s t p o te n t ia l co u ld be made w ith

k .v o .n .b c L 6 c JL .

1 .1 .4 T rap p in g exp erim en ts

B la k e & B o r re t t (1 9 5 2 ) sam pled w ild p o p u la tio n s o f k . v & i b a 6 c J L

u s in g s u c tio n tra p s and co lo u re d p ap ers im pregnated w ith o d o u rs,

b u t found n e ith e r method s u c c e s s fu l. B u t as k .\ ) Q A .b a 6 c .J i i s a t t ra c te d

p red o m in an tly to p a le b lu e , w h ite and y e llo w co lo u red flo w e rs

(Im am ura, 1935) and o th e r An th .n .zy iu .6 sp e c ie s have been reco rd ed on

s im ila r typ es o f flo w e rs (H in to n , 1 9 4 5 ), w h ite and y e llo w co lo u re d

in te rc e p t io n tra p s were s e t up in th e grounds o f the BM(NH) to

sam ple fo r A . 4a>ivU,c.u.4 o u td o o rs , complemented w ith su rv e y s o f flo w e rs

in in fe s te d a re a s .

The m a jo r ity o f s to re d p ro d u cts in s e c ts w i l l f l y tow ards l ig h t a t

some p e rio d in t h e ir a d u lt l i f e , and th e p resen ce o f p e s t sp e c ie s

can o fte n be d e te c te d in b u ild in g s and an e stim a te o f t h e ir p o p u la tio n

numbers made by c o lle c t in g th o se trapped a t windows and in l ig h t

f i t t in g s . Indeed Howe (1 9 5 7 ) quotes a number o f re p o rts w here th e

d e te c tio n and c o n tro l o f L a.6 jL ode ,> im a. A e ji tu L c o t in e , ( F . ) was advocated

by sm earing windows in w arehouses w ith eng ine o i l o r co v e rin g w ith

s t ic k y paper in o rd e r to c a tc h em erging a d u lt s . Museum s t a f f had

noted th a t A . acl'i y u .c.u a w ere commonly found on the in s id e o f w indow s,

on window s i l l s and w e ll illu m in a te d a re a s d u rin g th e summer m onths,

a p p a re n tly a tte m p tin g to escape o u td o o rs . T rap p in g in d o o rs was

c a r r ie d o u t, e x p lo it in g th e in s e c t s ’ p h o to ta c tic b e h av io u r to

in te rc e p t a d u lts a t windows in the museum, thus p ro v id in g in fo rm

a t io n on f l ig h t a c t iv i t y , in c id e n c e o f in fe s t a t io n s and e s tim a te s o f

p o p u la tio n s , a s w e ll as p ro v id in g a so u rce o f b e e t le s fo r d is s e c t io n s

to d eterm ine o v ip o s it io n a l s t a tu s .

A ttem pts by Peacock and Rogers (p e r s . comm.) to tra p A .4 am cc it4 in an

in fe s te d s to re room u s in g a Robinson m ercury vapour l ig h t tra p w ere

u n s u c c e s s fu l. H owever, they found th a t i f the U .V . l ig h t so u rce was

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re p la c e d w ith a tun g sten l ig h t b u lb , then sm a ll numbers o f b e e t le s

w ere caught in th e t r a p s . C o n seq u en tly , d u rin g the co u rse o f the

p re se n t stu d y an in te rc e p t io n tra p in c o rp o ra tin g a tu n g sten l ig h t

so u rce was desig ned and o p erated in th e s to re room.

1 .1 .5 O va ria n developm ent and ag e-g rad in g s tu d ie s

A g e -re la te d changes in b e h av io u r o f c e r ta in in s e c t sp e c ie s have been

shown to be a s so c ia te d w ith changes in the anatomy o f th e fem ale

re p ro d u c tiv e system . Where t h is o ccu rs i t i s o fte n p o s s ib le to

d eterm in e the c h ro n o lo g ic a l age o f fem ale in s e c ts from th e v a r io u s

s ta g e s o f o v a ria n developm ent. Such methods have been w id e ly used

in th e ag ing o f D ip te ra (D e tin o v a , 1 9 6 8 ), b u t few s tu d ie s h ave been

made on re p ro d u c tiv e developm ent in th e C o le o p te ra .

D ic k (1 9 3 7 ) observed a g e - re la te d changes in the fem ale re p ro d u c tiv e

o rgans o f T n .JLb o tiu m c.on£u.6um D u v ., and e s s e n t ia lly id e n t if ie d fo u r

s ta g e s o f o v a ria n development in a d u lt b e e t le s : im m ature, m atu re ,

p re o v ip o s it io n ( i . e . eggs in c a ly c e s ) , and p o s t- o v ip o s it io n , in

w h ich the c a ly c e s and o v id u c ts w ere d iste n d e d from p re v io u s o v i-

p o s it io n and d eg en eratin g egg f o l l i c l e s (co rp o ra lu t e a ) , w ere

p re se n t to a g re a te r o r le s s e r d eg ree . In more re c e n t s tu d ie s

w o rke rs have sco red o v a ria n developm ent u s in g a r b it r a r y s c a le s

w h ich th ey c o rre la te d w ith ag e . In V l a b ^ o c t l c a v j& ig jL fieA a Le C o n te ,

f iv e s ta g e s o f developm ent co u ld be re co g n ise d from em ergence o f

th e a d u lt to c e s s a tio n o f o v ip o s it io n some 40-50 days la t e r

(S h o rt & H i l l , 1 9 7 2 ). C o f fe lt & B u rk h o ld e r (1 9 7 3 ) re co g n ise d e ig h t

s ta g e s in LoL6X,odo,fima A eA su Lco sin e . ( F . ) b u t o n ly co n tin u ed t h e ir

in v e s t ig a t io n up to th e m a tu ra tio n o f th e f i r s t o o cytes ( i . e . th e

f i r s t 4 -6 days o f a d u lt l i f e ) . L ik e w is e G erb er (1 9 7 5 ) d e sc rib e d

f iv e s ta g e s o f o o cyte m a tu ra tio n in TdYUibfiJio m oJUXon. L . , b u t was

o n ly concerned w ith th e f i r s t g onad otrop h ic c y c le . G angesalingham

(1 9 7 4 ) s tu d ie d the m orphology and d if f e r e n t ia t io n o f the o va ry o f

S l t o p h l t u . 6 z euzmcuu M o tsc h ., from a d u lt emergence to d e a th . An age-

re la te d ra n k in g scheme was fo rm u la te d , b u t the maximum number o f

f o l l i c l e s in each o v a r io le was found d u rin g th e f i r s t 25 days o f

a d u lt l i f e , once an egg had been d isch a rg e d a d is t in c t co rp us

luteum was form ed and b e e t le s o ld e r than 50 days d id n o t m ature

fu r th e r f o l l i c l e s .

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An investigation was undertaken to determine if age-related changes were to be found in females of A.-6an.vuLc.u6. This was done by dissection of laboratory reared beetles from the start of the quiescent adult period to cessation of oviposition. Having defined criteria for age-grading, 'wild' beetles collected during the trapping experiments at the BM(NH) were dissected to ascertain whether or not beetles had mated and oviposited before they became flight active. Gut analysis was also used to determine whether or not those beetles collected from the insides of windows were individuals which had originated from outside or from within.

PLATE ISTAGES IN THE LIFE-CYCLE OF AWT H R E N U S SARWICUS

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(a). Active adult. Length 4mm. approx.

(b). Eggs. Length 0.75mm. approx.

(c). Early instar larvae. Length 1.5-2.Omm. approx.

PLATE IISTAGES IN THE LIFE-CYCLE OF A N T H R E N U S S A R N 1 C U S

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(a). Late instar larva. Length 6mm. approx.

(b). Pupa in last larval skin. Length 6mm. approx.

(c). Quiescent adult in last larval skin. Length 6mm. approx. (The pupal skin can be seen posteriorly).

46

PLATE IIISEXUAL DIMORPHISM IN A N T H R E N U S S A R N I C U S

Ventral view of female (left) and male (right) pupae removed from last larval skin to show the genital papillae.Length 5mm. approx.

iK>' ' JI

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1.2 Materials and Methods1.2.1 Habitat surveys

It was important to determine if was occupying birds'nests, and if so, whether it was competing or coexisting with the native A . v 2 J i b a 4 c . X , . Initial attempts at collecting birds' nests from buildings in the London area involved observing bird behaviour, looking for nesting activity and removing old nests by prior arrangement with the building's proprietors. Between November 1981 and March 1982 postal requests were sent to District Works Offices, Property Services Agencies, public buildings and pest control companies in the central London area, requesting their co-operation in obtaining birds' nests. Pest control companies were asked also for specimens of dermestid beetles from domestic infestations. In addition requests for specimens and birds' nests were published as notes in the Entomologist's Monthly Magazine (1981, 117 pg.xi), and Antenna (1982, 6(2) pg.218).

Material collected from these sources was brought back to the laboratory in sealed plastic bags and sorted within one week of collection. The nests were teased apart by hand and sieved through a 3mm sieve. The 'course' and 'fine' fractions were sorted separately in a white tray,illuminated overhead, and to some extent heated by, two 100W bulbs. Although rather tedious, this method was found to be more satisfactory than using Tulgren funnels, as the quantity of material to be examined was often very large and the presence of debris varying in size from large twigs to fine dust required much preliminary separation (also noted by Woodroffe (1953)). In addition the light and heat from the low wattage bulb used in the Tulgren apparatus was often insufficient to drive-out dermestid larvae or ptinid beetles from the nest material. All insects were removed, identified and counted, and where necessary larvae were reared through to the adult stage for identification. Only the A n t h t i o j i u . * data is dealt with in this thesis.

1.2.2 Outdoor activities of adults

Attempts were made to trap beetles outdoors in the grounds of the BM(NH) initially using two designs of white and yellow coloured

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interception sticky traps. The first type were modified aphid water traps (Figure 1.1a), composed of two upright baffles at right angles to each other to form a cross, (each vein measuring 22cm wide x 48cm high), fixed over a tray (45 x 45 x 8cm), containing water to which a little detergent had been added. The baffles were coated with a liberal layer of a proprietary sticky material,'Stick-Em' (J.T.Eaton & Co.,Inc.). Insects flying into the trap were either intercepted by the sticky coating or drowned in the water in the tray. Each trap was placed on a stand 0.8m high. One white and one yellow coloured trap were sited in a garden approximately 180 metres from the west wall of the museum building.

The second type of trap was a white circular plastic dish (17cm diam. x 6cm deep), fixed bottom surface uppermost onto the tops of poles hammered into the ground and approximately 1.4m high (Figure 1.1b). The outer surface of the dish was coated with a thin layer of Stick-Em. Eight of these traps were sited 2-4m from the west wall of the museum building and 3-5m apart from each other.The interception area of these traps (0.05m2) was much smaller than the modified aphid traps (0.85m2), but were considered to look superficially not unlike the tall white umbel flowers of Hogweed (HojiCLC.lo.um spp.) plants which are known to be highly attractive to feeding adults of A . v & i b a A c X , (Blake, 1961). Traps were placed only along the west west face of the building because this was out of public view, and it was considered by museum officials that siting them elsewhere may have spoiled the aesthetics of the building.Traps were operated between May and September 1982, checked weekly and all potential pest insects removed. Periodically, accumulated debris had to be removed from the sticky-surfaces which were then recoated with Stick-Em. Weekly maximum and minimum shade temperature readings were recorded at the garden site.

From the experience gained using these traps, white coloured traps of a more refined design were used for the 1983 and 1984 field seasons. These were composed of sheets of white flexible plastic (70 x 50cm), which were coated with a liberal layer of Stick-Em.The plastic sheets were folded lengthwise into a cylindrical shape with the sticky side outermost, and fixed to wooden poles using

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bolts and wingnuts. The advantages of these traps over those used previously was that if the sticky trap surface started to loose its efficiency through accumulations of debris and insects, the cylinder could be taken off the post and replaced. Four traps were sited 2-4m from the west wall and 8-10m apart. Traps were checked weekly, all potential pest insects removed, identified, and the An t k ^ 2, n a6 species retained for the dissections described in Section 1.2.19. Thermograph readings were recorded using a Casella 7-day instrument and chart papers replaced at weekly intervals. In 1983 traps were set up in the last week of May and run until the middle of September. In 1984 they were set up in early May and run until the end of September. In both cases trapping was terminated after no catches were observed in two consecutive weeks.

In addition to sticky-trapping approximately 15 minutes once a week was spent examining plants in the garden and grounds of the museum for k n £ k n . z n u . t > congregating on flower-heads. Any beetles found were collected, identified and specimens of A.-6a.>iyu,cu4 retained for dissection. At infrequent intervals during periods of peak flight activity of A.-6cl>i y u .c.il6 between 1982 and 1984, visits were made to Imperial College SW7, Kensington Gardens W8, Onslow Gardens SW7,Queens Gate Gardens SW7, and Jubilee Gardens WC2, to look for A n t l w . z n u . 4 on f lower-heads.

1.2.3 Window trapping

An experimental trial was conducted in 1982 in the General Herbarium, where large numbers of A.4a'inTcu4 had been reported at windows in previous years. Double-sided adhesive tape (3M Ltd.),25mm wide was stuck onto window-frame ledges with one edge close to the window pane for the full width of the window. These strips were coated with a liberal layer of Stick-Em. Beetles flying into the window-pane dropped on impact and fell onto the sticky-band below. A proportion of those that missed the sticky-bands on falling were caught subsequently as they crawled along the window ledges towards the light. Sticky-bands remained effective for 9-12 months, but those that lost their tackiness through accumulation of dust and debris, or which began to peel off the window ledge, were replaced as necessary. 6m of south facing window space was banded in the last week of April, and checked weekly until the first week of October. No record

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was kept of indoor temperatures during this trial.

As the preliminary trial proved to be very effective at trapping A. 6an.Yiic.ai>, more extensive sticky-band trapping was undertaken in 1983 and 1984. 12.5m of south and north facing windows were banded in the General Herbarium in 1983 and 1984. In 1982, building work prevented trapping on the windows in the Entomology Building, but 245.5m of north, south and west facing window on the six floors of the building were sticky-banded in 1983, and 219.7m in 1984. In 1983 windows were banded in the first week of April, in 1984 banding was carried out in the second week of April and these were checked weekly until the end of October. Collection of trap data in the Entomology Building was co-ordinated by Mrs.E.R.Peacock, who allocated one person on each floor of the building the task of checking the traps and recording captures; all specimens were sent to her for identification.

In all cases bands were checked weekly, when beetles were removed, identified and retained for later dissection. Insects from the Entomology Building were preserved in Pampel’s fluid (4pts. glacial acetic acid, 6pts. 40% formaldehyde, 15pts. 95% ethanol, 30pts. distilled water), because of the time delay in receiving the beetles at the laboratory for dissection. Thermohygrograph records were kept on the second floor of the Entomology Building using a Casella 7-day instrument, chart papers were replaced weekly, and temperature and humidity calibrations checked every four weeks.

1.2.4 Indoor light trapping

The Zoology store room of the BM(NH) housed a large collection of stuffed animals, bones and artefacts, which in 1980 were found to be harbouring A.4a.tiYuLc.ii6. This basement room had no outside windows and was in complete darkness except for occassional visits by staff.

A simple light-trap (referred to as a cylinder light-trap), was made from a clear plastic cylinder (30cm diam. x 50cm high), coated on its outer surface with Stick-Em and placed on a white plastic tray

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Figure 1.1 Interception sticky-traps used to sample A.6CLtinjLe.u.6 at the British Museum (Natural History).

(a) Modified aphid water trap(b) Dish trap(c) Outdoor cylinder trap(d) Cylinder light trap

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f(c.)

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(45.5 x 35.0 x 2.0cm), containing a layer of liquid paraffin. Illumination was provided from an 'Angle-poise' lamp with a 60W tungsten bulb, the light being directed downwards through the centre of the cylinder. Two traps were used in opposite comers of the room, placed against the walls. Insects flying towards the light source were either intercepted by the sticky cylinder or would hit the wall and drop into the liquid paraffin tray. With the traps in position, the light from one trap was not visible from the other, because of the rows of tall cabinets between them. The traps were set up in the middle of April 1982, and operated for 22 weeks. The trial was abandoned at the end of September when safety lighting was installed in the store-room which made light trapping ineffective. Traps were checked weekly when all insects caught were removed, identified and recorded.

1.2.5 Culture methods(i) Origins of stock

An initial stock of sixty A . a c l >i vU xlijl4 adults was obtained from the Agriculture Science Service, Slough Laboratory, in September 1981, and a further culture of approximately 200 larvae of unknown age from the same establishment in May 1982. These were descendants of a stock of larvae collected from a dead pigeon (C o l u m b a . sp.), at a military camp in Wiltshire, U.K., in 1966 (Woodroffe, 1967). Subsequently further cultures were started in 1982 and 1983 from adult beetles and larvae collected in the environs of the BM(NH), London SW7.

Two further A n i k t i m u * species, A . v Q A b a 4 c . j L and A, LauLpe4,were cultured for insecticide bioassay experiments. Both were started from stock obtained from the Slough Laboratory. A . v z . ' i b a . A c X . were descendants of beetles collected from flowers in south east England during the 1950's (Blake, 1955), and were supplemented with adults of indeterminate age collected from flowers during May-June in 1982-83 at Silwood Park, Ascot, Berkshire. The origins of the A.^£avLpe4 cultures were unknown. As far as could be ascertained, none of the stock had had any previous exposure to insecticides.

(ii) MediaStock cultures were maintained on a diet of fishmeal, yeast and

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cholesterol, in the proportions 50:12.5:1 by weight. The yeast and cholesterol were ground together with a pestle and mortar and then thoroughly mixed with the fishmeal, placed in glass ’Kilner' jars and sterilised in an oven at 60°C for 3 hours. This diet is referred to as "standard medium". In addition pieces of old, undyed, pure- woollen blanket material (45 x 15cm.), dusted with approximately 4gm of dried yeast, heat sterilised and rolled up into cylinders, were added to the cultures, providing an oviposition site for the adults and subsequently refuge and food for the larvae. The larvae of A. LauLpe.4 are voracious feeders, so the yeast treated wool was replenished periodically. A n t h t u m u . * cultures have been reared successfully on similar diets for over forty years (Griswold, 1941; Porter, pers. comm.).

(iii) Culturing proceduresA . 6 a n . v u , c u 6 and A.ueA6a4cX have circannual life-cycles in constant temperature rearing conditions, therefore the maintainance of serial cultures was initially difficult until sufficiently large stock culture populations had developed. From mid-May 1982 onwards, emerging adults were collected from stock cultures weekly (or daily during peak emergence periods), and placed in 71b. jars containing approximately 300gm of standard medium, plus a piece of yeast treated woollen material. Fresh cultures were set up after 4 weeks so that serial cultures started with 40-200 adults, and spaced at monthly intervals were available. A . f i l a v X p e , * has a much shorter life-cycle,5-7 weeks at 30°C on a diet of woollen fabric plus yeast (Ayappa d t a£.,1957), and new cultures were established at weekly intervals, from 100-200 adults taken from preceding cultures. Old cultures of A . ^ Z a v L p u were destroyed after 12 weeks. Glass jars were fitted with filter paper lids sealed in position with paraffin wax.

(iv) Rearing conditionsStock cultures of A . 6a'ivu,c.u.4 were first kept at constant conditions of 25 + 1°C, 50 + 10% relative humidity (rh), 16 hours light, 8 hours dark (16:8LD) photoperiodic cycle. Later studies showed that the optimum for larval development was closer to 20°C, therefore subsequent cultures were maintained at 20 + 1°C, 65 + 5% rh, 16:8LD photoperiod, as were the A.vevibaacZ cultures, k . l l a v L p o . 6 cultures were kept at 28 + 1°C, 70 + 5% rh, in constant darkness.

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(v) Control of opportunist pestsFlour mites, Ac.a'tu<6 6 JLa o L., and Psocids, L l p o t c z Z i A sp., were present in low numbers in most of the controlled temperature rooms used, and precautions were taken to prevent their entry into cultures. Jars were fitted with black filter paper lids sealed in position with paraffin wax (m.p. 60°C), and were placed on trays containing liquid paraffin, thereby preventing infestation from surrounding areas and effectively isolating infested cultures should outbreaks occur. The use of black filter papers made it easier to spot mites on the lids, and as a further safeguard jars and their lids were swabbed with absolute alcohol before opening. Despite these precautions contamination by A . 6 a jl o did occur on a few occa-S-ions in cultures of A m a i n t a i n e d at 28°C, 70% rh. The combination of high temperature and humidity, apart from favouring population build up of mites, tended to soften the paraffin wax seals and dampen the filter paper lids causing them to peel open at the edges. This was remedied by smearing jar rims with soft white paraffin wax to seal up any gaps, and no further infestations were encountered.

1.2.6 Control of physical environments

Experimental relative humidities were maintained in desiccators and air-tight plastic boxes using saturated salt and potassium hydroxide (KOH) solutions. For egg development experiments graded solutions of KOH were used to obtain the desired humidities (Solomon, 1951). For larval development experiments, which were in progress for extended periods of time, saturated salt solutions were used, as these are self-regulating at the equilibrium humidity. The particular salts used (Buxton, 1931; Solomon, 1951; Weast & Astle, 1982), and the actual humidities subtended are listed in Table 1.1. 100ml of the required saturated solution was placed in a 10cm diameter crystallising dish containing an excess of the solid phase, the dish was then placed in the bottom of the desiccator or plastic box.

For some temperature-humidity combinations suitable salts were not available, therefore KOH solutions were used. The specific gravity of these solutions was checked weekly by hydrometry, and adjusted as necessary by the addition of distilled water or concentrated KOH. Saturated salts were checked weekly to ensure that solutions had not dried-up or that salt was still present in excess. Strips

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Temp°C

Required humidity % rh20 30 70 90

12.5 - - KOH-

15.0 - -

NH,N0o 4 3(71.4) -

17.5 - -

NH.NO- 4 3(70.8) -

20.0 KC2H3°2(20.0)

CaCl2(32.3)

NH,N0~ 4 3(67.4)

ZnSO,(90.0)

25.0kc2h3o2(22.0)

CaCl2(31.0)

SrCl2(71.2)

BaCl2(90.2)

30.0 - -

NaNOo(72.8) -

32.5 - -

KOH-

Table 1.1 Saturated salt solutions used to maintain relative humidities at different temperatures.Where potassium hydroxide solutions were used this is indicated by KOH. Figures in parentheses are the actual humidities obtained.

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of cobalt thiocyanate paper (80 x 30mm. 0.55mg Co(CNS)2 percm2,BDH Ltd.), were placed in the environment chambers and the colour of these checked periodically against standard papers suspended over KOH solutions in 0.5 litre ground-glass stoppered bottles, pertaining to the required relative humidity for the appropriate temperature (simplified method of Solomon, 1957). Consistently there were no differences in colour between test and standard papers from qualitative observation by eye, and in view of the precautions taken it was considered that humidity was maintained well within the limits of + 5% rh.

Experimental temperatures were maintained in constant temperature rooms and thermostatically controlled cooled incubators, errors are indicated in the appropriate sections. Light-dark cycling was controlled with standard domestic time-clocks. For experiments where constant darkness was required, light-tightness was ensured by keeping boxes in a double layer of black PVC photographic bags (Gallenkamp Ltd.). This procedure was shown to be light proof by interleaving a piece of unexposed photographic film (Ilford FP4), in a black cardboard template and enclosing this inside a box with its double layer of PVC bags. The whole was exposed to direct illumination from two 100W bulbs for about 1 hour, but the developed film showed no sign of the template.

1.2.7 Egg development

Pairs of adults were placed in 4cm diameter plastic petri dishes with a 25 x 20mm piece of black flannel cloth, to provide a surface for the attachment of eggs. The cloth had been teased first with a wire brush, as a "woolly" substrate is preferred by ovipositing females. The dishes were kept at 20 + 1°C, 70% rh, 16:8LD photoperiod, and checked daily when pieces of cloth upon which eggs had been laid were removed and replaced with fresh cloth. The number of eggs on each piece of cloth were counted and the cloth plus eggs placed in open topped 50 x 25mm glass tubes. Newly laid eggs were fragile, and were not removed from the cloth because even careful handling with a camel-hair brush was found to result in high mortalities. These tubes containing 0-1 day old eggs were placed in desiccators at the required temperature- humidity combinations, and checked daily for emerging larvae at roughly the same time each day.

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In addition data on the duration of the egg stage and percentage hatch of eggs laid in the actual conditions in which they were to hatch were obtained from the oviposition and fecundity experiments described in Section 1.2.16.

1.2.8 Larval development - General

Larvae were reared on standard medium plus a small piece (20 x 15mm) of woollen blanket material. Medium was pre-equilibrated to the required temperature-humidity combinations by spreading thin layers alternating with 'Kimwipe' tissue (Kimberley-Clarke Ltd.), which were placed over KOH solutions subtending the required humidity, in desiccators at the required temperature for at least 1 week. For larvae reared in naturally fluctuating physical conditions, media was equilibrated to 20°C, 70% rh. Approximately 1.5gm of preconditioned medium was placed into each 50 x 25mm glass tube and compressed with a plastic plunger, just smaller than the inside diameter of the tube. Previous authors (Blake, 1958; Coombs & Woodroffe, 1983), did not compact the medium, but it was found that this greatly facilitated finding the early instar larvae (1-1.5mm in length), and their cast skins subsequently. The piece of woollen material was placed on top of the medium and the inside rims of the tubes coated with 'Fluon' (polytetra-fluoroethylene emulsion, I.C.I. Ltd.), to prevent larvae from escaping. Using Fluon eliminated the need for putting muslin closures over the tubes, thereby reducing the chances of ’’dead-spaces” occurring and hence eliminating the possibility of humidity gradients within the system.

Newly emerged 0-1 day old larvae from eggs laid by batches of 50- 100 adults and incubated at 25°C, 70% rh, were placed individually in the prepared tubes which were in turn put into sealed plastic boxes 26 x 15 x 9cm, each containing a dish with salt solution for the required humidity. Each box accommodated about 30 tubes. To prevent invasion of mites the gap between the box lids and rims were smeared with soft paraffin wax and boxes placed on trays of liquid paraffin. Boxes were observed weekly (unless stated otherwise in the sections below), when cast skins and dead larvae were removed and noted. At the onset of pupation they were observed daily and pupation, formation of quiescent adults and adult emergence noted.

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1.2.9 Larval development in constant conditions

The constant temperature-humidity combinations used for the experiments are indicated in Table 1.2. These larvae were reared in constant darkness, but in addition at 20 and 25°C only, larvae were also reared in a 16:8LD photoperiod. Because the larvae reared in darkness were exposed to light for short periods during weekly observations, thereby providing periodic disturbance and possible light cueing, one batch at each of 20°C, 70% rh and 25°C, 70% rh, were kept undisturbed in constant darkness. These were set up in parallel with the regularly observed batches, but not opened until the first pupation was noted in the regular inspections.

Larvae from the Slough Laboratory stock were used in all the temperature and humidity conditions described above, but because the beetles at the BM(NH) were of a ’wild' population and might have a different development rate, batches of larvae from museum stock were set up at 20°C and 25°C, 70% rh, in constant darkness and constant 16:8LD photoperiods. It was not known either at the start of these experiments whether the standard medium used was a nutritionally complete diet for A . t a ' u v L c . u * . A deficiency could have been responsible for the protracted life-cycle encountered in this species reared in the laboratory, although this was considered unlikely as many A n tk ^ io ,n u .6 species have circannual life-cycles. However two batches of larvae, one at 17.5°C, 70% rh, and one at 25°C, 70% rh, in constant darkness, were reared on a meridic (semisynthetic) diet which had been developed by Klein & Beck (1979) for T t io g o d z t im a .

spp., and other dermestid beetles. The composition of the diet is given in Table 1.3, and was made up by the procedure described by Klein & Beck (1979). Approximately lgm of preconditioned diet was placed in each tube without the addition of woollen material.

1.2.10 Larval development in naturally fluctuating conditions in a pigeon loft

Larvae were reared on standard medium in a pigeon loft at Silwood Park (Latitude, 51° 28' N.), where domestic pigeons were kept and reared. It was considered that the conditions of naturally fluctuating temperature, humidity and photoperiod experienced would be

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Temp°C

Relative humidity %rh20 30 70 90

12.5 + 1 - - X -

15.0 + 1 - - X -

17.5 + 1 - - X -

20.0 + 2 X# X# X# X#25.0 + 3 X# X# X# X#30.0 + 1 - - X -

32.5 + 1 - - X -

Table 1.2 Temperature-humidity combinations used in larval development experiments.(X) indicates constant dark only, (X#) constant dark and 16:8LD photoperiod.

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Dry diet components Lactalbumen

gm/lOOgm of dry diet 48

Glucose 36Fructose 12

Cholesterol 2

McCollum-Davis mineral mixture No.185 2

Fatty acidsMethyl linoleate

ml/ 10 0 gm 0.06

Methyl linolenate 0.06Vitamins

Nicotinic acidug/gm dry diet

25.0Thiamine 25.0Riboflavin 6.3Pantothenic acid 25.0Pyridoxine-HCl 12.5Folic acid 2.5Ascorbic acid 10 0 .0

Choline-Cl 10 0 .0

i-Inositol 50.0p-Aminobenzoic acid 25.0

Distilled water 20ml/lOOgm dry diet

Table 1.3 Composition of meridic diet used for rearing A . 6 a n . n X , c . u 6 larvae.

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similar to the bird nest habitats A n t k t i t m u are known to exploit.An initial batch of fifty 0-1 day old larvae, in individual rearing tubes as described above, were placed in boxes without humidity control, in the pigeon loft in July 1982. Second and third batches of 15-20 larvae (number depending upon availability), were added in September and November 1982. From January to September 1983 further batches were incorporated at monthly intervals. In addition batches of 15-20 larvae were reared in the same conditions but in constant darkness, to determine if photoperiod had any effect upon larval development and the initiation of pupation. These were placed in the loft at monthly intervals from February to September 1983 inclusive.

Larvae were examined weekly when cast skins and dead larvae were removed and noted. At the onset of pupation they were examined daily, but since emergence normally occurred in discrete groups, examination was reduced to once a week when all the first group of pupae had emerged, and increased again to daily when further pupae were seen. Maximum and minimum temperatures in the pigeon loft were recorded at weekly intervals from a maximum-minimum thermometer.

1*2.11 Larval development in fluctuating conditions in the laboratory

Larvae were reared on standard medium in a laboratory at Ashurst Lodge, Silwood Park, where they were subject to ambient conditions. One group of larvae were exposed to the 'natural' light conditions of the room, while the other group was kept in constant darkness.For both conditions batches of 15-20 larvae were started in February 1983 and further batches were incorporated at monthly intervals until September 1983 inclusive. Larvae were examined weekly when cast skins and dead larvae were removed and noted, at the onset of pupation they were examined daily. Maximum and minimum temperatures experienced in the laboratory were recorded at weekly intervals over the period of the experiment with a maximum-minimum thermometer.

1*2.12 Some effects of photoperiod on larval development

The effects of incremental changes in photoperiod on the rate of larval development were investigated at 20°C, 70% rh. A batch of fifty 0 - 1 day old larvae were subjected to increasing photoperiod,

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starting with a 7:17LD photoperiod during the first week, then \ hourly increments of the photophase each week until the 22nd., week, after which photoperiod was held constant at 18:6LD for the rest of the developmental period. A control batch of 50 larvae was kept in constant dark, except for the brief exposure to light once a week when cast skins were removed and recorded and pupations noted.

1.2.13 Effects of larval diet on development

As little was known of the natural habits of it wasimportant to determine the types of food which were capable of sustaining populations of this insect. The potential for larval development was investigated on the following diets:

1. Standard rearing medium.2. Dried T<LYio.bfiJio m o t i t o f i L., beetles.3. Old woollen blanket material.4. Old woollen blanket material soaked in a solution of

cholesterol and yeast and dried.5. Sterilised floor sweepings from a laundry room.6. Human hair.7. Sterilised sparrow (Pa44eA d o m t e t u n u ) nest material.8. Sterilised, dried guano and nest material of the feral

pigeon ( C o l u m b a L l v j Lcl) .9. Dried oak tree ( Q u e . s i c u 4 K o b u n . ) leaves.10. Old herbarium plant specimens (Compositae).

A small quantity of each (chopped or crushed where necessary), was placed in 50 x 25mm glass tubes and preconditioned at the experimental conditions of 20°C, 70% rh, 16:8LD photoperiod,for one week. 0-1 day old larvae hatched at 20°C from BM(NH) cultures were placed individually into the tubes. Thirty replicates were used for each diet. Tubes were examined every four weeks, until pupae were found, when observation was increased to once a week. No record was kept of larval moults, and mortality was calculated from the proportion of tubes which failed to produce live adults. Adults were weighed within the first 3 days of emergence from the last larval skin.

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1.2.14 Pupal and quiescent adult stages

Durations and mortalities of the pupal and quiescent adult stages at different temperature-humidity combinations were obtained from larvae pupating in Section 1.2.9. Observations were made at approximately the same time each day, thus the maximum recording error was + 1 day. Pupae were sexed using the genital papillae character described by Halstead (1963).

1.2.15 Effects of larval rearing conditions on adult emergence weight

Emergence weights of adult beetles from larvae reared at different temperature-humidity combinations were obtained from the larval development experiments of Section 1.2.9. Weights of beetles emerging from larvae reared on different diets at 20°C, 70% rh were obtained from Section 1.2.13. Beetles were weighed to the nearest microgramme on their first day of emergence from the last-larval skin using a Perkin Elmer AD-2Z Autobalance.

1.2.16 Effects of temperature on adult life and oviposition

Pupae were collected daily from stock cultures at 20°C, 70% rh, sexed, and the sexes kept separately in petri dishes at 20°C, 70% rh. Upon emergence from the last larval skin the active adults were weighed, paired and placed in 50 x 25mm glass tubes (rims coated with Fluon to prevent escape), containing a 25 x 20mm piece of 'teased' flannel cloth. As there are no reliable characters for determining the sex of adult beetles, males were marked by rubbing off a patch of scales on the right elytron, this greatly facilitated the recording of deaths of the sexes and avoided the need for dissection. Tubes were examined at 3 day intervals when the pieces of cloth with oviposited eggs were removed and replaced with fresh cloth. Tubes were also checked for eggs which had been "dropped" by females, or fallen off the cloth during handling. Egg numbers were recorded and used for the incubation experiments described in Section 1.2.7. Throughout the experiment beetles were not provided with food or water, and observation continued until both sexes had died. Fifteen replicate pairs were set up at 65-70% rh, and 15, 17.5, 20, 25, & 30°C, in constant darkness.

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1.2.17 Effects of adult diet on length of life, fecundity and oviposition

The methods used in this experiment resemble those of Blake (1961), in order to provide a comparison of the reproductive potential of A . w i t h A.ve'iba.4cL. As A. 4 c l s u v l c l l 6 has been found outdoors feeding on the pollen and possibly nectar of flowers, it was of interest to determine the effects of adult feeding upon fecundity. Since it was not possible to collect pollen in sufficient quantities from the plants upon which A . 6 cl>i y u .c i l 6 had been found feeding, pollen was gathered from Hazel ( C o s i y l u . 6 a v e Z l a n a L.), during March 1983; ample quantities could be obtained by tapping male catkins over wide-mouthed bottles. The nutritional composition of this pollen was unknown, therefore some groups of beetles were provided with a standard source of protein in the form of powdered egg albumen (Sigma Ltd.). Artificial "nectar" was made of the same sugar mixture as that used by Blake (1961), equal proportions of reagent quality sucrose, glucose and fructose, were dissolved in distilled water and made up to a total solution strength of 18% (w/w). Blake does not explain why she used this particular solution strength, and it is not known if this composition is analagous to that of nectar. In addition, water, which would be available periodically to beetles outdoors in the form of dew or rainwater, was provided to some groups of beetles as distilled water.

Liquid diets were made available to beetles by soaking absorbent polyporous strips (10 x 4 x 4mm), with the solution, excess being removed with filter paper. Strips given to beetles on a protein diet, were dusted with pollen or egg albumen as appropriate, using a camel hair brush, and were placed in the tubes so that they adhered to the sides of the glass.

For the first experiment conducted at 25°C, 70% rh, 16:8LD photoperiod, pollen was not available, and the egg albumen, sugar solution and distilled water were combined to give four different diets, control beetles were deprived of food and water, but given untreated polyporous strips. In a second experiment conducted at 20°C, 70% rh, 16:8LD photoperiod, when pollen was available, the food sources were combined to give six different diets, plus the control. The diets were, water, sugar solution, water & pollen, water & albumen, sugar solution & pollen and sugar solution & albumen. 20-25 replicate

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pairs of beetles were set up for each diet at the two experimental conditions.

The handling procedure was essentially the same as that in Section 1.2.16, except that tubes were examined daily, when eggs were removed and counted, deaths recorded, and feeder strips topped-up with diet as appropriate; strips were removed completely every 4 days. Egg fertility was recorded by maintaining the eggs in the experimental conditions in which they were laid and counting the proportion of eggs hatching for each female.

1.2.18 Ovarian development

The beetles used in this study were from BM(NH) stock kept at 20 +1 °C, 65-70% rh. Pupae were collected from cultures, sexed and the sexes placed separately in 10cm petri dishes lined with filter paper (Whatman No.l) at 20°C, 65% rh. They were examined daily when quiescent adults were removed and placed separately in 50 x 25mm glass tubes. Three groups each of 10 quiescent adults were dissected at 0-1, 2-4 and 7-8 days from the time of splitting of the pupal skin. Active adults were recorded as 0 days old on the day they emerged from the last larval skin, i.e., the first day after cessation of the quiescent stage. Eleven groups each of 10 females kept individually were paired with a single male on day 0 , and the females from each group dissected after 0-2, 3, 4, 6, 9, 12, 15, 18, 21,29, and 36 days of active adult life. In addition 3 groups of 10 unmated (virgin) females were dissected after 6,9 and 20 days of active life. Beetles were not provided with food or water and if the male of a pair died it was not replaced.

Beetles were dissected by sticking them with 'Bostik No.l' adhesive (Evode Ltd.), ventral side down onto black filter paper in the bottom half of a 10cm petri dish. The elytra and wings were removed and the petri dish filled with insect Ringer’s solution (Peacock, 1955) . The abdominal terga were removed and the size of the fat body scored on an arbitrary scale from 0-4. The criteria used were: [4] fat body filling entire abdominal cavity, organs not visible,[3] fat body less, particularly under the terga, usually gut vis

-49-

ible, [2] fat body less extensive, confined mainly to the sides of the abdominal cavity, gut and ovaries visible, [l] fat body slight, small amounts around viscera and abdominal margins, [0] fat body absent. The reproductive system was carefully removed, fat teased away, mounted in insect Ringer's solution on a microscope slide and examined at 30-100X by light microscopy. Scale drawings were made of an ovary from each beetle dissected, and the following measurements recorded using a calibrated eye-piece graticule: ovary length from top of the germarium to the base of the calyx; length of the most mature ovariole in the ovary, measured from the top of the germarium to the base of the ovariolar stalk; length of the most mature egg in the ovary.

1.2.19 Dissection of field collected beetles

All beetles collected in 1983 from window traps in the Entomology Building and General Herbarium and from outdoor traps and flowers, were dissected using the methods described in Section 1.2.18.

As far as possible beetles were dissected within 1-2 days of removing them from the sticky-traps, though most of the collected material from the Entomology Building was preserved in Pampel's fluid because it was not possible to dissect these specimens until some weeks after the collection date. This preservation procedure tended to result in some shrinkage of the viscera, but it was still possible to determine the ovarian stage and extent of the fat body. Before dissection the body length, measured from the frons to the tip of the elytra, was recorded. Sex was determined from the reproductive system, as the antennal character described by Woodroffe (1967), was considered unreliable. For males,only the size of the fat body and gut contents were recorded, no attempt was made to investigate age-related changes in the male reproductive system. The same criteria were used for scoring ovarian development and fat body size as described above, but in addition the alimentary tract was examined for signs of adult feeding. Because most of the specimens were dead at the time of dissection, it was difficult to see sperm within the spermatheca, but by tearing open the bursa-copulatrix and spermathecal duct and expelling the contents by applying pressure to the cover-slip, sperm could be detected when present.

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1.3 Results1.3.1 Habitat surveys

Of the 26 postal requests for birds' nests, 20 replies were received and 9 respondents supplied nest material. A total of 49 nests were collected. None of the pigeon nest material, which formed the bulk of the samples, was found to be harbouring Anth.sie.nuL6 larvae, but two Anthn.e.mi4 were found in the only sparrow's nest collected during the survey, from the Science Museum, London SW7. These were reared through to the adult stage and both were identified as female A. 6 a r u v L c . u . 4, indicating that A. 6 < u i r u L e . u 6 larvae do inhabit birds' nests. As Anthn.e.nub larvae had previously been found in pigeon nests in the BM(NH) ventillation towers, these sites were re-examined in some detail. Unfortunately they had been cleaned out and treated with a 50% emulsifiable concentrate of fenitrothion, the year prior to the start of this investigation.The small samples of guano collected from the towers did not contain AYithn.z.Yiu.6 larvae, although a number of cast larval skins were found. Moderate numbers of Pttnu.4 te.ctu6 Boie., and Ste.gobA.um pantc.zum (L.) beetles and larvae were present, indicating either that the disinfestation had not been completely successful or that re-invasion was occurring. Further pigeon nest material was collected from ventilation grilles on the front wall of the museum in 1983, but no Antk>iejiu4 larvae were found.

Following up an enquiry received by Rentokil Ltd., a large infestation of A .6a..Yu.c.u6 was discovered in July 1983 in an old clothing warehouse, Brixton, London SW9. Large numbers of dead and live adults were found on window sills, and further examination of the premises revealed large numbers of larvae (all ages), thriving on woollen floor sweepings, dust and debris, which had accumulated over many years under floorboards.

Additional responses were obtained from the published requests, 3 confirmed records of A . 6 c w .y u ,c u a were recorded: adults, but no larvae in a top floor flat, London Wl; 1 adult found at a window in a house, London SW13, and larvae were found infesting insect collection material in the Liverpool museum. The Liverpool infestation is the first record of this species outside the home counties and suggests

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that the species is increasing its distribution in the U.K. The origins of the infestation were not known, although it could easily have been introduced to the museum in infested loan or accession specimens or packaging materials.

1.3.2 Outdoor activities of adults

The preliminary trapping experiments in 1982 indicated that the white aphid traps were more effective at trapping A . 6 c A . n j . c . u 6 than yellow ones, with a total year catch of 37 for the former and only 12 for the latter (Figure 1.2). The white dish traps yielded a total of 43 A . 6a.n.YULC.u.6 (Figure 1.3), a larger number than the white aphid trap, despite their smaller total interception area. However, the two types of trap were located at different sites in the grounds of the BM(NH), and this may have had some influence on catch efficiency. A . v o n . b ( L 6 Q . L and A. I u.6 c.ul6 were also found on the traps. A . v z ^ i b a 6 c X , was only caught on the white ones (42 aphid, 26 dish), while A. ^ u 6 c . u 6 was also found, although in very small numbers, on the yellow trap (10 white aphid, 3 yellow aphid, 6 dish). A . 6 a ^ . n j . c u 6 was caught outdoors for most of the summer period, from the second week in May to the end of August. A . v Q . t i b a . 6 ( U . was most abundant in early June and no adults were caught after mid July. A. 6 u . 6 c . u 4 was never very abundant and appeared in small numbers between late May and early July, a single adult was caught in mid August.

Far larger numbers of A . 6 c M . n i . c u . 6 were caught on the traps used in 1983-84 (Table 1.4), with 1983 appearing to be a peak emergence year for the 3 years that systematic trapping was undertaken.

Species 1982 1983 1984A . 6 an.yuijc.u6 92 232 114A. VQA.bGL6C.JL 68 32 4A . I ul6c.ul6 19 109 12

Table 1.4 Total numbers of A n £ h > i Q . n u L 6 spp., caught on outdoor sticky-traps during the 3 year study.

Mea

n Te

mp.

°c.

N

umbe

r of

Ind

ivid

uals

.

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MAY JUNE JULY AUGUST

Figure 1.2 Weekly numbers of adults of three A n t k ^ e j i u . 6 caught on white & yellow coloured modified aphid interception traps in the grounds of the BM(NH) in 1982, with weekly mean temperatures during the trapping period.

Mea

n Te

mp

.°c.

N

umbe

r of

In

div

idua

ls.

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MAY JUNE JULY AUGUST

Figure 1.3 Weekly numbers of adults of three A n X k t i Q j m i * species caught on the white dish traps in the grounds of the BM(NH) in 1982, with weekly mean temperatures during the trapping period.

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In 1983 A. A C L t i n L c u . * was captured outdoors from mid-June to the first week of September, and in 1984 from mid-June to the second week of September (Figure 1.4). A.û4cti4 was numerous in 1983, particularly in the first two weeks of July, but in 1984 numbers had declined to about the 1982 level. A.i/e'iba-dcL was most abundant in 1982, but was never caught in as large numbers as A . A a t u v L c u A .

Examination of flowers in the gardens of the museum revealed that during favourable summer weather conditions A . 6 a t iyijLc.u6 does aggregate on flower-heads of a number of species of plant with white or yellow coloured flowers, where they feed on pollen and possibly nectar (Table 1.5). No A . A a ' i n X c . u A were found on flowers in other gardens in London, although small numbers of A . v Z A b a 6 c > L and A. u.4c.iz4 were found at some of these sites.

1.3.3 Window trapping

The total numbers of A.6an.viLc.uJ) caught in the General Herbarium traps for the 3 years is given in Table 1.6. As less window space was sticky-banded in 1982 compared to 1983-84, the total weekly numbers of beetles caught has been expressed in terms of the number of captures per metre length of window banded, thereby providing valid comparisons for the 3 years data. The general pattern of weekly capture numbers was the same for all 3 years (Figure 1.5). Beetles first appeared in early May, the peak abundance varied each year between early June and early August, and there were no further captures after the end of September. Temperature records were not kept in the General Herbarium, but the fluctuation in numbers correlated well with mean outdoor temperatures in 1982 (overlay to Figure 1.5). In 1983-84 thermograph records were kept in the Entomology Building, and though the absolute temperatures may have differed between the two locations, the mean weekly temperature changes would be similar because heating systems were off during the trapping periods. Thus the major influence on temperature at both locations would be the ambient outdoor conditions.On all occasions a rise in mean weekly temperature resulted in higher trap captures than the previous week, whereas a decrease in mean temperature generally resulted in a decline in numbers. Peak capture periods coincided with peak ambient temperatures. The total number of beetles caught per metre of window each year were: 94 in

- 55-

Figure 1.4 1983-84 captures of A n . t l v i e . m i 4 species on whitecoloured interception sticky-traps in the grounds of the British Museum (Natural History) and weekly maximum and minimum outdoor temperatures.

Date

V>l oro O

A oo\ o

9*6

9*91

9*£Z

9*0£

L'L

m L‘I

Z

L‘ Q

Z

9‘P 8*11

8*61

8*92

6* l 6*8

9*£

Temperature

°C—>

roO

Ol --

----

r

Number of individuals caught

t i

r

l -----r

i

vO 00 U>

wrrwuv? *V ?n3rrui/V9

1982----------- YEAR ------------

1983 19842nd.June SpXjiazantha sp. (6) 9th.June SpXjiozantha sp. (2)

7th.July Ro4a sp. (1)LXjguAttium ovatthottum (1 )

14th.JulyLigu6£>ium ovatthottum (6)

2 1st.Julykzhtttza mXJtzhottum (10)

28th.JulyAzhXJtza mULlo.holX.um (2)

4th.Aug Chtiytanthomum sp. (4) kc.h.XJLtQ.a. mXJtzhottum (1)

1 1 th.Augkc.hXJLto.CL mXJtzhottum (2)

22nd.June SpXjiazantha sp. (4) 5th.July

Ltgu&ttium ovatthottum (3) 1 2 th.July

Ltgu6tn.um ova.tthotX.um (5) 26th.July

kc.hXJ.tza mXJtzhottum (2)

YEAR R TOTALS 0 27 14

Table 1.5 Numbers of k . A a f i n t z u * (in parentheses) caught on flower-heads of plant species in the grounds of the BM(NH) between 1982-84.

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1982 1983 1984DATE TOTALS No./m

window DATE TOTALS No./mwindow DATE TOTALS No./m

window5.5 12 2.04 4.5 6 0.4813.5 43 7.31 11.5 7 0.56 10.5 8 0.6420.5 42 7.14 17.5 2 0.16 17.5 1 1 0 .88

26.5 10 1.70 25.5 3 0.24 24.5 3 0.242 .6 58 9.86 3.6 10 0.80 31.5 3 0.249.6 94 15.99 9.6 31 2.48 6 .6 5 0.4016.6 50 8.50 15.6 41 3.28 14.6 13 1.0423.6 38 6.46 23.6 78 6.24 2 2 .6 47 3.7630.6 14 2.38 30.6 100 8.00 29.6 62 4.967.7 40 6.80 7.7 183 14.64 5.7 40 3.2014.7 45 7.65 14.7 139 1 1 . 1 2 12.7 63 5.0421.7 30 5.10 21.7 138 11.04 18.7 103 8.2427.7 14 2.38 28.7 50 4.00 26.7 96 7.685.8 31 5.27 4.8 43 3.44 2 .8 1 1 2 8.96

1 1 . 8 13 2 . 2 1 1 1 . 8 8 0.64 9.8 86 6.88

18.8 8 1.36 19.8 2 0.16 16.8 77 6.1625.8 4 0.68 25.8 3 0.24 23.8 61 4.881.9 3 0.51 1.9 2 0.16 30.8 58 4.6415.9 2 0.34 8.9 3 0.24 6.9 25 2 .0 0

23.9 3 0.51 13.9 7 0.5620.9 3 0.24

YEART'TLS 554 94.2 849 67.7 883 70.6

Table 1.6 1982-84 weekly captures of A . 6 a t i r u , c . u 6 at window sticky traps in the General Herbarium.

Overlay to Figure 1.5

1982

I—I

\J1 <J1 VJ1 VJ1 CT\CTv CT\ CT\ ^ —J —J —I CD 03 00 CD 0 3 VO VO VO VOCol lection date

F&feVHfgyi ^S|Sr^l?Snera - Herbarium window trap captures of A .6dn.nJic.ii6

NUMBER OF BEETLES CAPTURED PER METRE OF WINDOW STICKY-TRAPPED

16 6014

12

108

6

42

1982

L b taVJl Oi roO roON ro VO OV ro04 04O -P* ro ro VJl 00 roVJl —a 03 VJl ro04VJl VJl VJl VJl OV CT\ OV ov OV —4 ■ o 03 03 CO 03 VO VO VO VO

io r

8 -

6 4 -

2 -rT~T-

1984

04 o -J ro 04 --j aro ro03 VJl ro VO roON ro VO ON ro04 04o OV 04 roo ro

VJl VJl VJl VJl VJl ov Ov ov ov - J - j 00 03 00 03 oo VO VO VO voCo I Iect i on date

Figure 1.5 1982-84 General Herbarium window trap captures of A.4a'uiXc.u-6

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1982, 68 in 1983 and 71 in 1984.

Total weekly captures of A n i k t i z y i u . * in 1983-84 for the Entomology Building are given in Table 1.7. Again because different window areas were banded in the 2 years, the data are expressed in terms of the total number of beetles caught per week per metre of window banded, and are presented on a log scale in Figure 1.6. The overlay to this figure of weekly maximum and minimum temperatures recorded in the Entomology Building indicates that to some extent catch numbers are influenced by ambient temperature conditions. Overall the pattern of captures for the 2 years was similar, peak numbers were recorded in mid-July in 1983 and late June in 1984. For both years no catches were observed after the first week in October. The total number of beetles caught per metre of window each year were:2.2 in 1983 and 1.8 in 1984. These figures are far lower than their equivalents for the General Herbarium, although direct comparisons are not possible particularly when one considers differences in building design which may influence the efficiency with which beetles are attracted to windows at the two locations.

1.3.4 Indoor light trapping

The pooled weekly captures of A . 6 a ^ y U , c . a ^ for the two traps are illustrated in Figure 1.7. Data for the week ending 14th. July was not available because the bulbs in both traps had blown when they were checked on this date, and as only a very small number of beetles were found on the traps, it was assumed that the lights had not been operational for most of that trapping period. A. A a t u v i c u . * was caught in the traps from the start in mid-April up until the end of September when the experiment was abandoned. Trap catches were at their peak between mid-June and mid-July. Numbers declined in late July and by the middle of August only small numbers (2-3 per trap) were caught each week. Trap captures would have been influenced somewhat by the room being lit while staff visited the store. Certainly during late August to September the room-lights were on most days for much of the working day, which may have aggravated the rapid decline in trap captures from this period.

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1983 1984

DATEA . A a n

TOTALS.yiL c.ul6No./mwindow

A.vtznbaAcJLTOTALS

A.ÛACJUATOTALS DATE

A. 6a.f TOTALS

iruLdULv No./in window

A.v e n b a A C A .TOTALS

A.fiuACUA

TOTALS

15.4 - -22.4 2 0.00829.4 - -

6.5 1 0.004 4.5 - -

13.5 - - 11.5 - -20.5 3 0 .0 12 18.5 - -

27.5 - - 24.5 - -3.6 2 0.008 1 . 6 3 0.014

10 .6 5 0.020 8 .6 2 0.00917.6 29 0.118 15.6 13 0.05924.6 47 0.191 1 2 2 .6 40 0.182 3 1

1.7 40 0.163 1 29.6 67 0.305 48.7 107 0.436 2 6.7 63 0.287 1

15.7 142 0.578 1 13.7 59 0.269 1

22.7 73 0.297 1 20.7 44 0.200 1

29.7 31 0.126 1 27.7 40 0.1825.8 14 0.057 3.8 30 0.137

1 2 . 8 15 0.061 10 .8 9 0.04119.8 7 0.029 17.8 10 0.04626.8 2 0.008 24.8 - 2 0.0092.9 5 0.020 31.8 6 0.0279.9 1 0.004 7.9 2 0.00916.9 3 0 .0 12 14.9 3 0.01423.9 1 0.004 21.9 3 0.01430.9 - - 28.9 - -

7.10 1 0.004 5.10 1 0.005 -

YEART'TLS 531 2.16 1 6 397 1.81 8 3

Table 1.7 1983-84 weekly captures of An t h s i m u A spp., at windowsticky-traps in the Entomology Building.

TEMP

ERAT

URE

°e

-E9-

€86V

NUMB

ER O

F BE

ETLE

S/ME

T^|B

fpgf

^J‘(J^

£IOp

£:a I e)

m *

0.002

0J|

«5.4. ^ uxoitui ^ »ifl* JPi&F^'vtc&P s .

CoiteEtlbfit'adlSlWg k Mfihg)°^ ^ Building window trap captures of A.4a^^Xca4.

NUM

BER

OF

BEE

TLES

/MET

RE

OF

WIN

DOW

(L

og

10

sca

le)

*

o oC o l le c t io n date (week ending)

Figure 1.6 1983-84 Entomology Building window trap captures of

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^ Ln Ui L n L n C T ' C T ' C T ' C T ' ^ ' v j — l — l 0 0 0 0 0 0 00 vO vOv£)APRIL MAY JUNE JULY AUGUST SEPT.

C o lle c t io n d a te

F ig u re 1 .7 1982 w eekly c a p tu r e s o f k . 6a.tiYiLc.u.6 in th e c y l in d e r l i g h t

t r a p s lo c a te d in the Zoology s t o r e room.

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1 .3 .5 Egg developm ent

The d u ra tio n o f the egg s t a g e and p e rc e n tag e h atch over a ran ge o f

tem p erature-h um id ity com bin ation s fo r eggs l a i d a t 2 0 °C, 70% rh ,

and th o se l a i d in the c o n d it io n s in which they h atch ed , i s shown

in T ab le 1 .8 . The ran ge o f en viron m en tal tem p eratu res over which

egg h atch o ccu rred was 1 5 .0 - 3 2 .5 °C , and the in cu b a tio n p e r io d d e

c r e a s e d w ith r i s e in tem p eratu re (F ig u re 1 .8 ) . D if fe r e n c e s in egg

h a tch were o b served between the two s e t s o f d a ta . None o f the egg s

l a i d a t 20°C and t r a n s fe r r e d to 15°C h atch ed , w hereas 34% o f th o se

l a i d a t 15°C h a tch ed . In a d d it io n the d u ra tio n o f the in cu b a tio n

p e r io d was s i g n i f i c a n t l y sh o r te r fo r eggs l a i d a t 25°C compared to

th o se l a i d a t 20°C and t r a n s fe r r e d to 25°C . For eggs l a i d a t 30°C

th e p e r io d was s l i g h t l y s h o r t e r , bu t the d i f f e r e n c e was n ot s i g

n i f i c a n t . The h ig h e s t p e rc e n ta g e h atch reco rd ed was 85% a t 25°C ,

70% rh .

Humidity a f f e c t e d the in cu b a tio n p e r io d and p e rce n tag e h a tch o f e g g s .

In th e tem p erature ran ge 20-30°C an in c r e a se in hum idity d e c re a se d

th e d u ra tio n o f the egg p e r io d . However, d i f f e r e n c e s a t each temp

e r a tu r e were sm a ll and n ot s t a t i s t i c a l l y s i g n i f i c a n t . T h is may be*

due to the f a c t th a t egg h a tch was on ly reco rd ed a t 24hour i n t e r v a l s .

At 25 and 30°C the p ro p o r t io n s h a tch in g were s i g n i f i c a n t l y low er fo r

e g g s h a tc h in g in the c o n d it io n s in which they were l a i d . G e n e ra lly

fo r any o f the 3 h u m id it ie s u sed a t each tem p eratu re , the h ig h e s t

h a tch reco rd ed was a t 70% rh , b u t a t 2 7 .5 °C i t was a t 90% rh .

1 .3 .6 L a r v a l developm ent in c o n sta n t c o n d it io n s

F ig u re 1 .9 shows the frequ en cy d i s t r ib u t io n s o f p u p atio n tim es fo r

la r v a e re a re d under d i f f e r e n t c o n sta n t environm ental c o n d it io n s .

F or each tem p erature-h um id ity com bination t e s t e d , ex ce p t a t 15 °C ,

where p u p atio n was d i s t i n c t l y b im o d al, the b u lk o f the p u p a tio n s

o ccu rre d between weeks 36 and 64 . Some in d iv id u a ls a t a l l temp

e r a tu r e s however, pupated a t in fre q u e n t in t e r v a l s a f t e r th e main

p u p atio n p e r io d . At 25°C a few la r v a e from both Slough L ab o ra to ry

and BM(NH) s to c k s p upated a f t e r only 9-20 w eeks.

m

Temp°C

%rh

Laid at 20°C, 7 0 % rh aid in hatch conditions Sig.of diff. between ipean incubgtion Denods (t-test)

Sig.of diff. between,* RllSh(d-test)

No.used

Mean period (days) + SE

Range (days)

No.hatch

%hatch

No.used

Mean period (days) + SE

Range(days)

No.hatch

%hatch

15.0 30 38 - - 0 0.070 26 - - 0 0.0 287 43.8 + 0.16 40-46 97 33.8

17.5 70 387 30.3 _+ 0.08 28-33 235 60.720.0 30 75 26.0 + 0.15 24-28 53 70.7

70 115 25.1 + 0.10 24-27 95 82.6 569 25.0 +_ 0.05 22-28 426 74.9 N.S. N.S.90 75 24.9 +_ 0.14 23-27 57 76.0

25.0 30 100 15.2 + 0.09 14-16 81 81.070 102 15.1 + 0.07 14-16 87 85.3 517 14.5 +_ 0.05 12-16 392 75.8 p<0.001 p<0.05

27.5 30 98 14.6 + 0.11 13-16 51 52.070 83 14.4 + 0.11 13-16 43 51.890 79 13.9 + 0.12 13-15 45 57.0

30.0 30 94 11.0 + 0.12 10-12 46 48.970 122 10.8 + 0.08 10-12 77 63.1 138 10.7 +_ 0.13 9-12 43 31.2 N.S. p<0.00190 106 10.6 + 0.10 10-12 58 54.7

32.5 30 43 - - 0 0.070 57 10.3 + 0.14 10-11 12 21.190 46 - - 0 0.0

Table 1.8 Duration of the egg stage (days) and percentage hatch of eggs under different temperature and humidity conditions for eggs laid at 20°C, 70%rh and in the conditions in which they hatched. N.S.= no significant difference.

-68-

P

Figure 1.8 Effect of temperature on the duration of the eggincubation period.Error bars indicate 95% confidence limits.

L.~ -Reared in constant Dark o Reared in 16: 8 LD photoperiod T VMean pupation times Q).- .

.00 s Eo. 4 15 ° c.700/o rh , ::J::J 2 zo. . _ .. - - - ... • • •••••• ... -- ...-

'" < '. '.~' •• " ••••••

t '90' '92' '94' '96' '98'

'lOd 110t \04' \06' ',oa' '110' T

17·5°c. 70% rh I· •• 1 •• 11_ .•. I 20° c. 200/0 rh I T V

• -ca ..... ... -=:J r-II-. _ Ii}. -=:I .nn- e - c - ... c:::I - 0

200c.300/0rh I dl.IJy V

• ..::1 ____ 111 00-c e:.- - ...

200c.70% rh I. V T I

BM(NH)stock e- .or.lj I b ., 0"

\.0 ... -- - • - 0 CI I

200c.700/orh 'n~w:wL •• 0 0 e n -20°c.900/orh · .rb. iJJJ- • .JJ- ..::I

25°c.200/0rh , V

~ 11::1 .... ... ""0 n...... • c -=:I - -25°c.30 0/orh

25°c. 70o/0.f.b .. BM ( NH) stock T V

•• c .... D =-' I I b I I:M -=:J CloD -=s 0 Cl ... 25°c.70% rh·

.. ' V T

"""""" ... 00 __ -r-IIII •• IIC)a.-oo.......n e n..-.On r::I

25°c.90 % rh T V

• -=-111 UJ - c:::I - n 0

30oc.70o/~ rh T _. -' 1_.- • •• • 17·5 DC. 70% rh T

Mer\dlc diet __ •• 1111.1 __ • 25°c.700/orh Meridic diet T

_ .- .llal .a_. _ • - - •

'10' ',2

' '14' '16'

'18' '20' '36' '36'

'40' '42' '44' '46' '48' 'so' '52' '54' '56' '58' '60

' '62' '64' '66' '66' '70' 'n' ',74.' '76' '78' '60' 'a2' '84' '86' '6'0 • '90' '92' '94' '96' '~' '),od \02' • i

104

TIME TO . PUPATION (WEEKS)

Figure 1.9 Frequency distributions of pupation times for A. -6al(lt.l.c.U-6 larvae reared under

envi.ronmental conditions.

-70-

Larval development data were analysed using the GLIM statistical package (Baker & Nelder, 1978). GLIM was used because it allows one to fit a series of models, as in a stepwise regression, so that the statistical significance of treatment effects may be measured while controlling for differences in the overall variability between treatments. At the time of producing the model the 15°C data were not available, therefore these results were added later and were not included in the analysis of variance. It was considered that this did not alter the statistical significance of the model because 15°C is at the extreme end of the developmental range, resulting in extended larval development periods and number of instars, which if anything would have increased the significance of treatment effects. In the initial stages of modelling it was determined that rearing larvae in constant dark or 16:8LD photoperiods, or on meridic v. standard diet, did not affect development, and there were no differences between stock from the Slough Laboratory and the BM(NH). Temperature, humidity and sex however, did have significant effects on the duration of larval life and number of larval moults. The results of the final model, which includes only the significant factors, is given in Appendix I. Data are tabulated as series of means and standard errors for development times and number of moults for each sex, and the significance of treatment effects tested by 3-way analysis of variance. These data are plotted as histograms in Figure 1.10, along with additional information on the proportions of larvae surviving to pupation.

Sex had a significant effect upon the duration of larval life, with males pupating earlier than females. The shortest mean rate of development was 41 weeks for males and 43 weeks for females at 20°C,90% rh (Figure 1.10a). Taking into consideration larval survivorship however, which was low at 90% rh (Figure 1.10c), optimal developmental conditions were closer to 20°C, 70% rh, over the humidity range tested. Larval life was significantly shorter and survivorship highest at 20°C. The number of larval moults were significantly different between the sexes and both temperature and humidity had a large effect upon the number of moults before pupation (Figure 1.10b). Males underwent consistently fewer moults than females for all temperature-humidity combinations tested.

- 71-

Figure 1.10 The effect of temperature and humidity on:(a) the duration of the larval period(b) the number of larval moults(c) the percentage of larvae surviving to pupation

Larv

al p

erio

d (w

eeks

)

P

Larv

al p

erio

d (w

eeks

)

-Zl-

\ \

\ \

\h-1

I—Ui

v£) h-

LoNo.

of larval moults

90

70

50

30 % surviving to

pupation

<5. %

\ \

\ \

\M-

H-*Ln

VD u>

No.

of l

arval moults

-£L~

-74-

The least number of moults observed was at 17.5°C, 70% rh, and 70% rh appeared to be optimum in terms of lowest number of ecdyses before pupation at all temperatures.

As the GLIM model predicted that rearing larvae either in constant dark or in a 16:8LD photoperiod had no significant effect upon development, only the results for larvae reared from Slough Laboratory stock in constant dark are considered further. The length of time larvae remained in each instar was calculated for each temperature-humidity combination and this data is illustrated in Figure 1.11. This shows the range of times larvae remained in each instar and the median value, i.e., the time taken for 50% of larvae to moult to the next instar or pupate. Larvae failing to survive to pupation were not included in the analysis, therefore declining numbers of larvae represents pupation. Most larval deaths occurred at the 1 st instar stage, deaths in mature larvae were usually associated with abnormal moulting behaviour, involving an excessive number of moults terminating in a failure to ecdyse properly, or failure to moult after an extended larval instar. In 'normal' larvae development was characterised by fairly regular instar durations up to the 4th or 5th instar, then an extended instar duration between the 6th and 9th instars, depending upon temperature-humidity conditions, terminating in pupation or further regular moults before pupation (e.g. Figure l.lld-f). At 20°C the protracted period was generally the 6th or 7th instar (Figure l.lld-g), while at 25°C it was the 7th, 8th or 9th instar (Figure l.llh-k). The longest instar duration recorded was 40 weeks at 15°C, 70% rh (Figure 1.11a). At the temperature extreme of 30°C (Figure 1.11c), and high humidities (Figure l.llg & k), extended larval instars were not as obvious, instead larvae continued to moult at frequent but irregular intervals, resulting in a large number of larval instars before pupation. At high temperature-humidity combinations this 'abnormal' development may have arisen because of mould growth in the rearing medium.Since larvae left on mouldy food invariably died, they had to be transferred to fresh food as soon as fungal growth became apparent. This introduced additional variables into the experiment, namely, change of food quality and excessive disturbance, both of which have been shown to affect larval development in other dermestid beetles (Burges, 1959).

- 75-

Figure 1.11 Durations of larval instars (weeks) and numbers of larvae remaining in each instar for larvae reared in constant temperature-humidity conditions. The declining number of larvae represents pupation, vertical lines (|) indicate the range of instar durations and dots (f) the median duration.

WEE

KS

N

UM

BER

OF

LAR

VA

E

40

30

20 -

10 -

24 r

20 -

16 -

12 -

8 -

4 -

b c.

17-5 ° c 3 0 °c70% 70%

15°ca.

IN STAR

WEE

KS

NU

MBE

R

INSTARFigure 1.11 (contd.)

WEE

KS

N

umbe

r of

lar

vae

20% 30% 70% 90%

1 2 3 A 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 1011 12 131415

Fiaure 1.11 (contd.)INSTAR

-7 9 -

1.3.7 Larval development in naturally fluctuating, conditions in a pigeon loft

The data presented from this investigation are incomplete as a proportion of the larvae introduced to the experimental conditions from March 1983 onwards appear to be undergoing semivoltine development and had not pupated by October 1984. It is hoped to continue observations into 1985 for final publication. The weekly maximum and minimum temperature records and approximate daylengths (including civil twilight), for latitude 50°N., are recorded in Appendix II.

All of the 1st instar larvae introduced to the experimental conditions between November 1982 and February 1983 died within a few weeks without moulting. The pupation frequencies for August '82 and September '82 larvae are complete, those for March '83 onwards represent only the univoltine individuals (Figure 1.12). All the pupations in 1984 occurred within a 9 week period from the end of May to the end of July, regardless of when larvae were introduced to the experimental conditions. This meant that some larvae underwent an extended developmental period of up to 106 weeks, while others pupated at around 50 weeks, a period similar to larvae reared at constant temperature-humidity conditions (Section 1.3.6).The proportion of larvae which were univoltine or semivoltine was related to the time of year they were introduced into the pigeon loft (Table 1.9). The majority of larvae starting development early in the year had grown sufficiently to overwinter as mature larvae and pupated the following spring/summer. Those starting development from July onwards had only a short favourable period before the onset of winter conditions and therefore overwintered as young larvae, requiring a second period of active growth before overwintering as mature individuals and pupating the following year when favourable conditions returned. The main difference between larvae reared in natural photoperiod and in constant dark was in the proportions of univoltine and semivoltine individuals, with a larger proportion of those reared in constant dark requiring 2 years to complete larval development. The overwintering instar was dependant upon the maturity of larvae at the onset of unfavourable conditions. Figure 1.13 shows the range of durations of each instar, the overwintering instar is indicated by an ex-

NUMBER OF INDIVIDUALS PUPATING

-8 0 -

September '8294_______________ m n ___________

March '83

April '83

May '83

June ’83

July '83

65

jsa. £ 2 .60

54P53 1

52

I E$3— rea

47

Pupation dataTTT-In r i H J T 1 j-a. 1 hO 1n r r n r r ho■P" i— -P- 00 Ln ho vO cr>

-O L/i CP1 CT> CT' CP *JJuly 1983 May June July 1984

= constant dark □ = natural photoperiod

Figure 1.12 Pupation dates of larvae reared under outdoor conditionsin a pigeon loft, introduced as 1 st instar larvae into the experimental conditions at Monthly intervals. Numbers indicate the duration of larval life (weeks) of the first individualto pupate in each batch. (-- > indicates data is incomplete& further pupations are expected in 1985).

- 81-

Month i n+roduced

NATURAL PHOTOPERIOD CONSTANT DARK

No.used

MORT.%

%surv pupat 1 y r .

i vors i ng in

2yrs.No.

usedMORT.

%

% sur pupat 1yr.

v i vors i ng in 2yrs.

A u g .* 8 2 50 5 0 .0 8 . 0 9 2 .0 - - - -

S e p t . *82 15 4 0 .0 0 . 0 1 0 0 .0 - - - -

N o v . ' 82 15 1 0 0 .0 - - - - - -J a n . ' 8 3 15 1 0 0 .0 - - 15 1 0 0 .0 - -

F e b . ' 83 15 1 0 0 .0 - - 15 1 0 0 .0 - -M ar.* 8 3 15 > 6 .7 9 2 .9 7 .1 ? 20 > 1 0 .0 6 1 .1 3 8 .9 ?A p r i l * 83 15 > 1 3 .1 9 2 .3 7 .7 ? 2 0 > 2 0 .0 5 0 .0 5 0 .0 ?May '8 3 15 > 0 . 0 9 3 .3 6 .7 ? 17 > 1 1 .8 6 6 .7 3 3 .3 ?J u n e '8 3 19 > 2 1 .1 6 6 .7 3 3 .3 ? 15 > 6 .7 3 5 .7 6 4 .3 ?J u l y * 83 17 > 1 1 .2 4 6 .7 5 3 .3 ? 14 > 1 4 .3 0 . 0 100?A u g . ' 83 19 > 1 5 .8 0 . 0 100? 15 > 6 .7 0 . 0 100?S e p t . '8 3 17 > 2 9 .4 0 . 0 100? 16 > 1 8 .8 0 . 0 100?

Tab le 1 .9 P ro p o rtio n o f la rv a e p u p atin g in 1 o r 2 y e a rs when

in tro d u ce d as 1 s t in s t a r la rv a e to outdoor c o n d it io n s

in a p igeon lo f t and exposed to n a tu ra l p h o to perio d o r

co n sta n t d a rk fo r the d u ra tio n o f la r v a l developm ent.

? in d ic a te s p ro p o rtio n exp ected to pupate in 1985.

- 82-

tended p e r io d . F o r exam ple , la rv a e in tro d u ce d to th e e xp e rim e n ta l

c o n d it io n s in August '8 2 sp en t th e ir f i r s t w in te r in the 3 rd o r

4 th in s t a r and the second w in te r in th e 6 th o r 7 th in s t a r . Those

in tro d u ce d in M arch '8 3 e n te red th e w in te r as 5 th o r 6 th in s t a r s .

In f a c t o v e rw in te rin g o ccu rre d a t a l l in s t a r s a p a rt from th e 1 s t

w here m o rta lity was 100%.

1 .3 .8 L a r v a l developm ent in f lu c tu a t in g c o n d it io n s in the la b o ra to ry

W eekly maximum and minimum tem p eratu res a re reco rd ed in Appendix I I .

In g e n e ra l tem peratu re v a r ia t io n s throughout the y e a r w ere s m a ll.

The b u lk o f the developm ent d a ta i s p re sen ted in T a b le 1 .1 0 . D if

fe re n c e s in the d u ra tio n s o f la r v a l developm ent p e rio d s were observed

between la rv a e re a re d in n a tu ra l p h o to perio d and tho se in co n sta n t

d a rk (F ig u re 1 .1 4 ) . In co n sta n t d a rk a l l groups developed w ith

a p p ro x im a te ly the same mean p e r io d , ran g in g from 40-45 w eeks. T h is

re s u lte d in p u p atio n s o c c u rr in g between the b eg in n in g o f December

'8 3 and the b eg in n in g o f J u ly '8 4 - a p e rio d o f 32 w eeks. In n a tu ra l

p h o to p erio d how ever, the d u ra tio n o f the la r v a l p e rio d d ecreased

th e la t e r in the season th e la rv a e w ere in tro d u ce d in to the e x p e r i

m en ta l c o n d it io n s . F o r exam p le , la rv a e in tro d u ce d in Fe b ru a ry had

a mean p e rio d o f 59 weeks and tho se in Septem ber, 37 w eeks. By

com parison w ith la rv a e re a re d in co n sta n t c o n d itio n s w here the mean

deve lo pm enta l p e rio d was around 40-52 weeks (S e c t io n 1 . 3 . 6 ) , la rv a e

in tro d u ce d e a r ly in the season underw ent a p ro lo n g a tio n o f la r v a l

l i f e , w h ile tho se in tro d u ce d la t e in th e season underw ent an a c c e l

e ra te d la r v a l p e r io d . T h is re s u lte d in a l l b a tch es o f la rv a e pup

a t in g w ith in a p e rio d o f 18 w eeks, from la t e Fe b ru a ry to m id Ju n e .

A l l b a tch es o f la rv a e re a re d in co n sta n t d a rk showed s im ila r p a tte rn s

o f m o u ltin g , w ith s l ig h t ly extended 6 th o r 7 th in s t a r s (F ig u re 1 . 1 5 ) .

In n a tu ra l p ho to perio d ho w ever, the p a tte rn o f m o u lting v a r ie d

between b a tc h e s , w ith extended in s t a r d u ra tio n s o c c u rrin g between

th e 5 th and 8 th in s t a r s , w h ich w ere g e n e ra lly o f lo n g e r d u ra tio n

than those in co n sta n t d a rk . C e ssa tio n o f m o u lting was c o in c id e n t

w ith the se a so n a l d ecrease in p h o to p erio d and to some e x te n t temp

e ra tu re , between m id-O ctober ’ 83 and m id -Feb ru ary '8 4 (A ppend ix I I ) . .

-83-

F ig u re 1 .1 3 D u ra tio n s o f la r v a l in s t a r s (w eeks) and numbers

o f la rv a e rem a in in g in each in s t a r fo r la rv a e

re a re d in f lu c tu a t in g c o n d itio n s in a p igeon l o f t

e ith e r in n a tu ra l p ho to perio d o r co n sta n t d a rk .

Newly emerged la rv a e w ere in tro d u ce d in to the

e xp e rim e n ta l c o n d it io n s in the month in d ic a te d .

The d e c lin in g number o f la rv a e re p re se n ts

p u p a tio n , v e r t ic a l l in e s ( | ) in d ic a te the range o f

in s t a r d u ra tio n s and d o ts ( f ) the m edian d u ra t io n .

1*

-8 4 -Naturai PhotoperiodNatural Photoperiod

Wee

ks

No.

of

larv

ae

Wee

ks

No.

of

larv

ae

Wee

ks

No.

of

larv

ae

NATURAL PHOTOPERIOD CONSTANT DARK-8 5 -

INSTAR INSTAR

Figure 1.13 (contd.)

+

/

Wee

ks

No.

of

larv

aeW

eeks

<ji T cn m 3 oo co

cn 1

N) CO ■r- cn

ro oCO o

—r

\ W \ h-

/ H \ i

o n l

cn 3

No.

of

larv

ae

Wee

ksN

o. o

f la

rvae

cn Tcn

c= CD U)

cr)

o

cncn

CP co

NATURAL PHOTOPERIQD CONSTANT DARK

No. of larvae Length of larval life (weeks) Number of larval moults Adult emergence weight (mg.)MONTH LARVALSTARTED TOTAL M F MORT.% TOTAL MALE FEMALE TOTAL MALE FEMALE TOTAL MALE FEMALE(a) NATURAL PHOTOPERIOD •FEBRUARY 20 12 7 5.0 58.7+0.82 59.0+0.79 58.3+1.87 7.7+0.24 7.3+0.19 8.3+0.52 4.90+0.19 4.64+0.35 5.35+0.96MARCH 15 5 8 13.3 53.8+0.81 53.2+1.24 54.1+1.11 7.2+0.20 6.6+0.24 7.6+0.18 5.18+0.66 4 . 4 7 + 0 . 2 2 5.6 2+0.41APRIL 19 7 11 5.3 52.2+0.62 50.9+0.99 53.1+0.72 7.6+0.12 7.4+0.20 7.6+0.15 5.21+0.14 4.80+0.20 5.46+0.15MAY 18 8 8 11.1 47.9+0.46 47.9+0.83 47.9+0.44 7.2+0.14 7.1+0.13 7.3_+0.25 4.84+0.19 4.41+0.21 5.27+0.26JUNE 19 6 12 5.3 44.9+0.31 44.7+0.56 45.0+0.39 6.6+0.17 7.0+0.37 6.3+0.14 5.24+0.15 4.79+0.26 5.46+0.16JULY 18 7 10 5.6 42.9+0.39 43.4+0.48 42.5+0.56 6.1+0.22 5.6+0.20 6.4+0.31 5.32+0.20 4.60+0.13 5.83+0.22AUGUST 19 11 8 0.0 39.4+0.46 38.5+0.41 40.6+0.75 6.5+0.16 6.4+0.15 6.6+0.32 5.48+0.12 5.12_+0.10 5.97+0.08SEPTEMBER 20 6 14 0.0 37.2+0.55 36.3+0.76 37.5^0.72 6.0+0.14 5.8_+0.17 6.0+0.18 5.37+0.16 4.78^0.29 5.63^0.16

(b) CONSTANT DARKFEBRUARY 21 10 9 9.5 44.9+0.81 45.4+1.33 44.3+0.93 7.7+0.15 7.9+0.26 7.4+0.18 5.24+0.15 4.75+0.11 5.78+0.16MARCH 15 8 6 6.7 42.1+0.78 41.1+0.93 43.5+1.18 7.0+0.20 6.6+0.26 7.3+0.21 5.60+0.23 5.12+0.31 6.24+0.12APRIL 20 9 10 5.0 39.4+0.57 39.2+0.81 39.6+0.83 7.0+0.14 6.7+0.24 7.2+0.13 5.71+0.15 5.35+0.17 6.03+0.19MAY 18 9 9 0.0 40.8+0.51 40.8+0.88 40.8+0.57 7.1+0.17 6.7+0.17 7.4+0.24 5.38+0.19 4.85+0.23 5.91+0.20JUNE 20 7 11 10.0 40.3+0.38 39.9+0.71 40.6+0.43 7.2+0.12 7.3+0.18 7.1+0.16 5.61+0.24 5.21+0.31 5.87+0.32JULY 20 7 11 10.0 43.5+0.72 42.6+1.13 44.1+0.94 7.4+0.16 7.3+0.36 7.5+0.16 5.25+0.21 4.68+0.31 5.61+0.22AUGUST 20 10 9 5.0 41.6+0.56 41.0+0.83 42.2+0.74 6.8+0.19 6.6+0.27 7.1+0.26 5.02+0.13 4.71+0.17 5.36+0.11SEPTEMBER 19 8 11 0.0 41.0+0.39 40.8+0.53 41.2+0.57 6.7+0.11 6.6+0.18 6.7+0.14 4.55+0.11 4.22+0.16 4.79+0.09

Table 1.10 Development of A.6 a > i r u , c . u . 4 in fluctuating conditions in the laboratory (a) in natural photoperiod (b) in constant dark.

108642

00P•H4-icd&a.V )1-cd'd•H>.5U-lO(Dz

-8 8 -

.□ n.

v F e b ru a ry

Hnnllnn n

M arch

n H n n n n n

A p r il

.D-n Jl n. n n

T V May

✓

n .n l i i i . i i -August

lm u i

Septem ber

34 35 36'37 38 39*40*4r 42*43*4?45*461 47* 481 491 50* 511 521 531 54* 551 5^ 5"/ 581 5^ 6cf 6 6 6D u ra tio n o f la r v a l s ta g e (w eeks)

1— l

= constant dark ■ = natural photoperiod V T = mean value

F ig u re 1 .1 4 P u p atio n fre q u e n c ie s o f A .4am icu-6 re a re d in th e la b o ra to ry

under f lu c tu a t in g tem peratu re and h u m id ity c o n d it io n s .

- 89-

Figure 1.15 Durations of larval instars (weeks) and numbers oflarvae remaining in each instar for larvae reared in fluctuating conditions in the laboratory either in natural photoperiod or constant dark.Newly emerged larvae were introduced into the experimental conditions in the month indicated. The declining number of larvae represents pupation, vertical lines (|) indicate the range of instar durations and dots ({) the median duration.

*

reek

s N

o.of

lar

vae

Wee

ks

No.

of

larv

ae

1 2 3 4 5 6 7 8 9 10 11

15 i-

1 2 3 ‘ 4 5 6 7 8 9 10 11INSTAR

Constant Dark

1 2 3 4 5 6 7 8 9 10 11

1 2 3 4 5 6 7 8 9 10 11INSTAR

Wee

ks

No.

of l

arva

e W

eeks

N

o. o

f la

rvae

W

eeks

N

o. o

f la

rvae

- 91-

Wee

ks

No.

of

larv

ae

Wee

ks

No.

of

larv

ae

Wee

ks

No.

of

larv

ae-92-

INSTAR INSTAR

-93-

1 .3 .9 Some e f f e c t s o f p h o to perio d on la r v a l developm ent

The regim e o f in c re a s in g p h o to p erio d reduced the le n g th o f the

la r v a l p e rio d (F ig u re 1 .1 6 a ) . In co n sta n t d a rk the mean p e rio d was

4 4 .7 weeks ( S . E . 0 . 6 4 ) , s im ila r to th e r e s u lt s o f S e c tio n 1 . 3 . 6 .

In in c re a s in g p h o to perio d the mean p e rio d was o n ly 2 5 .4 weeks ( S . E .

0 . 7 6 ) , a lth o u g h a sm a ll p ro p o rtio n (7 % ) , took 40-43 w eeks. The

p h o to p e rio d ic reg im e a ffe c te d bo th th e d u ra tio n and number o f la r v a l

in s t a r s (F ig u re 1 .1 6 b ) . In co n sta n t d a rk , la rv a e underw ent an

extended 6 th o r 7 th in s t a r and the m a jo r ity pupated a f t e r co m p letin g

7 o r 8 in s t a r s . Under in c re a s in g p ho to perio d a m arked ly in c re a se d

in s t a r d u ra tio n was n o t ap p aren t and most la rv a e pupated a f t e r com

p le t in g 6 in s t a r s . T h is in d ic a te s th a t in co n sta n t d a rk a la r v a l

’ r e s t in g ' p e rio d i s re q u ire d b e fo re pup atio n can take p la c e , w h ile

under in c re a s in g pho to p erio d th e re s t in g p e rio d i s m arked ly reduced

o r a b se n t.

1 .3 .1 0 E f f e c t s o f la r v a l d ie t on developm ent

D ata were a n a ly se d u s in g the GLIM s t a t i s t i c a l p ackag e , and i s ta b

u la te d in Appendix I I I as a ta b le o f means and stan d ard e r ro r s fo r

developm ent t im e s , and the s ig n if ic a n c e te s te d by a n a ly s is o f v a r

ia n c e . D ie t had a s ig n if ic a n t e f f e c t upon the r a te o f co m p letio n o f

th e la r v a l s ta g e . F ig u re 1 .17 i l lu s t r a t e s the p u p atio n fre q u e n c ie s ,

most pupated between weeks 3 6 -5 0 , b u t some, p a r t ic u la r ly on d ie t s

w h ich were p ro b ab ly n u t r it io n a l ly in co m p le te ( e . g . b la n k e t m a t e r ia l) ,

rem ained in the la r v a l stag e fo r up to 93 weeks b e fo re p u p atio n took

p la c e . On a d ie t o f d r ie d T z n z b ^ o b e e t le s , some la rv a e pupated a f t e r

o n ly 10-16 w eeks. T a b le 1 .1 1 shows th e mean la r v a l developm ent p e r

io d s on the d if f e r e n t d ie t s w h ich a re ranked in o rd e r o f s u i t a b i l i t y

fo r developm ent u s in g the param eter lo g S /T d e riv e d from Howe (1 9 7 1 ) .

T h is in d ex condenses two k in d s o f in fo rm a tio n , the p ercen tag e o f

in d iv id u a ls co m p le tin g a stag e o f th e l i f e - c y c le (S ) and th e d u ra tio n

o f t h is stag e ( T ) , in to one e x p re s s io n . L a rv a e re a re d on d rie d p la n t

m a te r ia ls , nam ely oak le a v e s and h erb ariu m sp ecim ens, d ie d as 1 s t

in s t a r la rv a e w ith o u t fe e d in g .

-9 4 -

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8 9INSTAR

Figure 1.16 Effects of constant dark and a regime of increasing weekly photoperiod on (a) the duration of the larval period and (b) the duration and number of larval instars.(Decreasing numbers of larvae in (b) represents pupation).

1.Standard rearing mediumi ••t

2.Dried beetlesj=f=L

3Q.t_d)XIE

3.Woollen blanket material

4.Woo I & yeast + cholesterol

5.Floor sweepings

6.Human hair

7. Sparrow nest material

8.Pigeon guano

nj=n. n _Q=l

_n__ r-H

JH

JZT"1—i .m .-.O .

— «— T~1

IvOL/i

i i i i i i r ' r n A i m i i n ~i~ i i i i i i i t r i i r i i i r n m i i i i i i i i i i i i i i i i i i i i i i n i i i' i i i i r i i n10 12 14 16 18 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84 86 88 90

WEEKS

Figure 1.17 Effects of larval diet on the pupation frequencies of A , 6 a ^ . n J L c . u 6 at 20°C, 70% rh, 16:8 LD photoperiod

-96-

Diet

Mean period

(weeks) T.SSsurv i va 1

S. log S/TStand ard medium 4 2 .2 80 .0 0 .1 0 4 (2 )

D rie d b e e tle s 3 3 .3 83 .3 0 .1 3 3 (1 )

Wool m a te r ia l 6 6 .4 36 .7 0 .0 5 4 (8 )

Wool + y e a s t & c h o le s te ro l 4 6 .8 66 .7 0 .0 9 0 (5 )

F lo o r sw eepings 5 3 .5 5 3 .3 0 .0 7 4 (7 )

Human h a ir 4 7 .1 4 3 .3 0 .0 8 0 (6 )

Sparrow n e s t m a te r ia l 4 5 .1 6 3 .3 0 .0 9 2 (4 )

P igeon guano 4 1 .9 66 .7 0 .1 0 0 (3 )

Oak tre e le a v e s - 0 .0 - (= 9 )

H erbarium specim ens - 0 .0 - (= 9 )

T a b le 1 .11 L a r v a l deve lopm ental p e rio d s (T ) and p ercen tag e

s u r v iv a l (S ) on v a r io u s d i e t s , to g e th e r w ith t h e ir

grow th in d ic e s ( lo g S / T ) . The ra n k o f the d ie t i s

g ive n in p a re n th e se s .

»

-9 7 -

1 .3 .1 1 P u p a l and q u ie sc e n t a d u lt sta g e s

T a b le 1 .12 shows the d u ra tio n s o f the p u p al and q u ie sc e n t a d u lt

s ta g e s fo r a range o f tem p era tu re -h u m id ity c o n d itio n s in co n sta n t

d a rk . The d u ra tio n s o f bo th sta g e s d ecreased w ith r i s e in tem pera

tu re (F ig u re 1 . 1 8 ) . Th ere were no d iffe re n c e s between d u ra tio n s o f

m ales and fem ales fo r the tem p era tu re -h u m id ity co m b in atio n s te s te d .

A t 20 & 25°C th e re was a tendency fo r the d u ra tio n o f the p u p a l

sta g e to d ecre ase w ith in c re a s e in h u m id ity , b u t d iffe re n c e s were

n o t s ig n if ic a n t . S u c c e s s fu l p u p atio n and a d u lt emergence o ccu rre d

a t a l l co n sta n t tem peratu res a t w h ich la r v a l developm ent was p o ss

ib le , i . e . 1 5 -3 0 °C . P up a l m o r ta lity was v e ry v a r ia b le and d id n o t

appear to be c o rre la te d w ith tem peratu re o r h u m id ity . The h ig h e s t

m o r ta lity reco rd ed was 20% a t 25°C , 90% r h . No m o rta lity was ob

se rve d in the q u ie sc e n t a d u lt stag e o ve r the tem peratu re and h u m id ity

range te s te d .

1 .3 .1 2 E f f e c t s o f la r v a l re a r in g c o n d it io n s on a d u lt emergence w e ig h t

D ata on em ergence w e ig h t o f a d u lts from la rv a e re a re d in co n sta n t

te m p era tu re -h u m id ity c o n d it io n s w ere an a lyse d as p a r t o f th e GLIM

model d e sc rib e d in S e c tio n 1 . 3 . 6 . The ta b le s o f means and stan d ard

e r ro r s and the 3-way a n a ly s is o f v a r ia n c e i s ta b u la te d in Appendix

I . The r e s u lt s a re i l lu s t r a t e d as h isto g ram s in .F ig u r e 1 .1 9 . Th e re

was a se x d if fe r e n c e , w ith fem ales b e in g s ig n if ic a n t ly h e a v ie r than

m ales a t a l l tem p era tu re -h u m id ity co m b inatio ns te s te d . Em ergence

w e ig h t was a fu n c t io n o f th e fa v o u r a b ilit y o f th e environm ent fo r

la r v a l developm ent. The h e a v ie s t a d u lts w ere reco rd ed from la rv a e

re a re d in c o n d it io n s most fa v o u ra b le fo r ra p id la r v a l developm ent,

th e optimum in the range te s te d b e in g 20°C , 70% r h .

As d ie t d id n o t a f f e c t th e r a te o f la r v a l developm ent i t was n o t

in c lu d e d in th e f in a l GLIM m odel. H ow ever, d ie t d id have a s ig

n if ic a n t e f f e c t upon emergence w e ig h t. L a rva e re a re d on m e rid ic

d ie t re s u lte d in s ig n if ic a n t ly h e a v ie r a d u lts than tho se re a re d

on stan d ard medium (p < 0 . 0 5 ) , a t 1 7 .5 & 25°C (T a b le 1 .1 3 ) .

PUPAL STAGE Q U IE SC E N T ADULT STAGEMALES & FEMALES SEX ES POOLED MALES & FEMALES SEX ES POOLED

Temp rh sex No. % Range Mean period % Range Mean period No. Range Mean period Range Mean period°C % used mort (days) (days) + SE mort (days) (days) + SE used (days) (days) + SE (days) (days) + SE15.0 70 M 15 13.3 35-39 36.6 + 0.33 35-39 36.8 + 0.20 13 15-18 16.5 + 0.24 15-19 16.8 + 0.1812.1 15-19 —

F 18 11.1 35-39 36.9 + 0.25 16 17.0 _+ 0.24 —17.5 70 M 22 0.0 27-31 28.6 + 0.23 22 11-15 12.7 + 0.30 11-15 12.7 + 0.190.0 27-31 28.6 + 0.16 11-15 —

F 20 0.0 27-31 28.5 + 0.22 20 12.7 + 0.30 —20.0 20 M 11 9.1 17-20 18.3 + 0.30 10 9-14 11.0 + 0.54 9-15 11.4 + 0.367.7 17-21 18.5 _+ 0.22 9-15 —

F 15 13.3 17-21 18.6 + 0.31 13 11.7 _+ 0.4930 M 16 12.5 17-19 17.8 + 0.21 14 9-14 10.7 + 0.40 9-14 10.7 + 0.2319 8.6 17-19 17.7 + 0.12 18 9-14 —

F 5.3 17-19 17.7 + 0.14 10.7 _+ 0.2870 M 28 0.0 16-19 17.7 + 0.15 28 8-14 10.0 + 0.30 8-14 10.0 + 0.242.2 16-19 17.7 _+ 0.12 9-14 —

F 17 5.9 16-19 17.6 + 0.20 16 10.0 _+ 0.4290 M 16 12.5 16-18 17.0 + 0.21 14 8-13 10.1 + 0.41 8-14 10.3 + 0.289.7 16-19 17.1 + 0.16 9-14 —

F 15 6.7 16-19 17.2 + 0.24 14 10.4 + 0.3925.0 20 M 8 12.5 9-14 11.6 + 0.69 7 5-8 6.1 + 0.40 6.5 + 0.2711.1 9-14 11.6 + 0.43 — 5-9F 10 10.0 9-14 11.7 + 0.58 9 6-9 6.8 _+ 0.36

30 M 10 0.0 9-14 10.8 + 0.55 10 5-9 6.5 + 0.40 5-10 6.6 + 0.290.0 9-14 10.7 + 0.33 5-10F 13 0.0 9-14 10.7 + 0.43 13 6.7 _+ 0.43 —70 M 23 4.4 9-13 10.5 + 0.25 22 5-10 6.3 + 0.32 5-10 6.5 + 0.249.5 9-14 10.7 + 0.23 5-10F 19 15.8 9-14 10.9 + 0.41 16 6.7 + 0.38 —90 M 10 20.0 8-13 9.6 + 0.32 8 4-8 5.9 + 0.44 4-8 6.2 + 0.2820.0 8-14 10.3 + 0.40 5-8

—F 10 20.0 9-14 10.9 + 0.69 8 6.5 _+ 0.33

30.0 70 M 13 7.7 8-10 8.6 + 0.23 12 3-6 4.4 + 0.29 4.5 + 0.204.8 8-10 8.6 + 0.17 — 3-6F 8 0.0 8-10 8.5 + 0.27 8 4-6 4.3 + 0.25 —

Table 1.12 Effects of temperature and humidity on the duration and mortality of the pupal and quiescent adult stages. M=male, F=female.

DA

YS

-99-

Figure 1.18 Effect of temperature on the duration of (A) the pupal period and (B) the quiescent adult period. Error bars indicate 95% confidence limits.

-100-

*

32

Figure 1.19 Effect of temperature and humidity during larval development on adult emergence weight.

Adult emergence weight (mg)

Adult emergence weight (mg)

-101-

Temp

°C

Mean em ergence w e ig h ts (mg) +SE

STANDARD MED. MERIDIC D IET

m ale fem ale m ale fem ale

1 7 .5 5 .6 2 6 .2 4 7 .72 8 .3 2

+0.09 +0 .10 +0.13 +0.12

2 5 .0 3 .4 1 4 .2 8 6 .49 6 .9 5

+0.32 +0.20 +0.18 +0.27

T a b le 1 .1 3 Mean em ergence w e ig h ts o f a d u lt b e e tle s d e riv e d from

la rv a e re a re d on sta n d a rd medium and m e rid ic d i e t .

The range o f la r v a l d ie t s te s te d a t 20°C , 70% rh a ls o had s ig n if ic a n t

e f f e c t s upon a d u lt emergence w e ig h t (F ig u re 1 .2 0 & Appendix I I I ) .

D ie ts w h ich favo u red ra p id la r v a l developm ent re s u lte d in h e a v ie r

b e e t le s a t em ergence.

1 .3 .1 3 E f f e c t s o f tem peratu re on a d u lt l i f e and o v ip o s it io n

The r e s u lt s a re g ive n in T a b le 1 .1 4 .A n a ly s i s o f v a r ia n c e showed

th a t th e re w ere no s ig n if ic a n t d iffe re n c e s in emergence w e ig h ts o f

m ale and fem ale b e e t le s a llo c a te d to th e f iv e e xp e rim e n ta l temp

e ra tu re s . A se x d iffe re n c e was o n ly reco rd ed a t 25 & 30°C , where

fem a les w ere s ig n if ic a n t ly h e a v ie r than m a le s . Th e re w ere , how ever,

s ig n if ic a n t d iffe re n c e s in the lo n g e v it ie s o f m ales and fem ales

( la y in g and n o n - la y in g ), between the f iv e tem peratu res and the

g e n e ra l tren d in th e r e s u lt s in d ic a te d th a t b e e t le s liv e d lo n g e r

a t lo w er te m p e ra tu re s . A p a rt from 15°C th e re were no s ig n if ic a n t

d iffe re n c e s between the lo n g e v it ie s o f la y in g and n o n -la y in g fe

m a le s ; mean v a lu e s in d ic a te d th a t n o n - la y e rs liv e d lo n g e r b u t the

v a r ia n c e was la rg e .

S u c c e s s fu l o v ip o s it io n o ccu rre d a t a l l tem peratu res t e s te d , and

s ig n if ic a n t d iffe re n c e s w ere reco rd ed fo r the number o f eggs la id

o ve r the tem peratu re ra n g e . The optimum was 20°C w here the h ig h e s t

re co rd ed fe c u n d ity was 82 e g g s/fe m a le , and the le a s t fa v o u ra b le ,

30 °C ,w h ere the h ig h e s t fe c u n d ity was 33 eg g s/fem a le . A la rg e de-

#

-102-

CO o—1 TO> —z mo o>70 a>o mm2 -Hm r~o m— COc2

x: -< c ■ no m oo > o or ~ CO r- or ~ —i r ~ 7 0m mz + z CO£2 o 2 m> 3: > m—1 o T>m I— m7 0 m z— CO — CD> —i > COr ~ m r-

o p®

>TO

<*Figure 1.20 Mean emergence weights of beetles derived from larvae

reared on different diets at 20°C, 70% rh.Error bars indicate 95% confidence intervals.

«

SPARROW NEST

1 5 .0TEM PERA

17 .5TU R E °C

2 0 .0 2 5 .0 3 0 .0Sign.of F-ratio

Male emergence weight (mg) 3.99+0.18 (15) 3.96jK).21 (15) 4.08+0.21 (15) 3.99+0.19 (15) 4.00+0.18 (15) N.S.Female emergence weight (mg) 4.29+0.21 (15) 4.53j+0.23 (15) 4.31+0.33 (15) 4.59j|j0.19 (15) 4.5 7jE 0.21 (15) N.S.Difference between male & female wts. (t-test) N.S. N.S. N.S. * *

Male longevity (days) 53.H2.57 (15) (36-72)

46.6+2.50 (15) (32-65)

30.5+1.79 (15) (21-43)

26.8je2.16 (15) (18-53)

20.1je1.04 (15) (12-26)

***

Longevity of laying females (days) 55.9+4.45 ( 9) (38-82)

40.0^3.30 ( 9) (23-52)

41.6je3.12 (11) (23-60)

41.6je1.59 (12) (31-52)

22.2je3.30 ( 6) (11-33)

***

Longevity of non-laying females (days) 77.5+8.83 ( 6) (52-107)

60.5je10.1 ( 6) (21-94)

55.3je9.37 ( 4) (29-73)

57.3jE 10.9 ( 3) (36-72)

26.9je2.73 ( 9) (15-42)

*•*

Mean No. of eggs/laying female 31,9j+3.93 ( 9) (18-52)

43.0+4.60 ( 9) (21-59)

51.7+6.31 (11) (28-82)

43.1je4.99 (12) (18-79)

23.0_e4.08 ( 6) (6-33)

**

Diff. between longevity of laying & non-laying females (t-test)

* N.S. N.S. N.S. N.S.

Correlation between male emergence weight 8, 1ongev i ty

r=0.73*

r=0.81N.S.

r=0.82N.S.

r=0.56N.S.

r=0.41N.S.

Correlation between emergence weight of laying females & longevity

r=0.70*

r=0.64N.S.

r=0.68*

r=0.76**

r-0.49N.S.

Correlation between emergence weight of laying females & No. of eggs laid

r=0.32N.S.

r=0.64N.S.

r=0.76*#

r=0.52N.S.

r=0.57N.S.

Correlation between longevity of laying females & No. of eggs laid

r=0.63N.S.

r=0.82**

r=0.75**

r=0.68*

r=0.43N.S.

Key Da+a presented in form: mean j+ S.E. (n)(Range)

* significant at p < 0.05, ** significant at p < 0.01, *** significant at p < 0.001 N.S. no significant difference, r Pearson's coefficient of product-moment correlation

T a b le 1 .1 4 E f f e c t s o f tem peratu re on a d u lt l i f e and o v ip o s it io n a t 70% rh in co n sta n t d a rk

-eo

i-

- 104-

g re e o f v a r ia b i l i t y was noted in the number o f eggs la id by in d iv

id u a l fem ales a t a l l te m p e ra tu re s . A t a l l tem peratu res a number o f

p a ir s f a ile d to produce eg g s, the maximum was 60% a t 30°C and the

minimum 20% a t 25°C .

S ig n if ic a n t lin e a r c o r re la t io n s (P e a rso n ’ s c o e f f ic ie n t o f p ro d u ct-

moment c o r r e la t io n ) , were reco rd ed between a d u lt em ergence w e ig h t

and lo n g e v ity fo r bo th m ales and o v ip o s it in g fem ales a t a l l temp

e ra tu re s a p a rt from 30°C fo r bo th sexes and 1 7 .5 °C fo r fe m a le s .

In a l l ca se s the tre n d was fo r h e a v ie r in d iv id u a ls to l i v e lo n g e r

than lig h t e r o n es. A p a rt from a t 20°C no c o r re la t io n was app aren t

between fem ale em ergence w e ig h t and number o f eggs o v ip o s ite d . In

th e tem peratu re range 1 7 .5 -25 °C c o r re la t io n s between fem ale lo n

g e v ity and number o f eggs o v ip o s ite d w ere s ig n if ic a n t , in d ic a t in g

th a t the lo n g er fem ales l i v e the more eggs they o v ip o s it .

1 .3 .1 4 E f f e c t s o f a d u lt d ie t on le n g th o f l i f e , fe c u n d ity and o v ip o s it io n

( i ) R e s u lts a t 25°C

P a ir s o f b e e tle s la y in g le s s than 10 eggs were exclu d ed from the

a n a ly s is . The p e rcen tag es o f such p a ir s fo r the f iv e d ie t s o f no

fo o d , w a te r , w a te r & album en, su g ar s o lu t io n and su g ar s o lu t io n

& albumen w e re : 9 . 1 , 1 3 .0 , 5 . 0 , 9 .1 & 8.7% re s p e c t iv e ly . Th e re

d id n o t appear to be any c o r re la t io n between d ie t and the p rop

o r t io n s o f n o n -la y in g fe m a le s . A n a ly s is o f v a r ia n c e showed th a t

th e re w ere no s ig n if ic a n t d iffe re n c e s in emergence w e ig h ts o f

m ales and fem ales between the f iv e groups o f b e e tle s a llo c a te d to

th e d if fe r e n t d i e t s . However, s ig n if ic a n t d iffe re n c e s in w e ig h t

betw een m ales and fem ales w ere observed in b e e tle s a llo c a te d to

♦ th re e o f the d ie t s and fo r the pooled d a ta (T a b le 1 . 1 5 ) . D ie t

o n ly s ig n if ic a n t ly in c re a se d th e le n g th o f a c t iv e a d u lt l i f e in

b o th se xe s when su g ar (c a rb o h y d ra te ), was in c lu d e d (T a b le 1 . 1 6 ) .

S ig n if ic a n t lin e a r c o r re la t io n s w ere o n ly found in un fed m ales and

fem a le s and m ales on a d ie t o f w a te r & album en, in a l l c a se s the

re g re s s io n eq u atio n , showed th a t h e a v ie r b e e tle s liv e d lo n g e r than

lig h t e r o n es.

«

♦

D ie t

2 5 °C 2 0 °C

MALES FEMALES.o if f .between

sexes MALES FEMALES

. o j f f . between

sexes

No food 3.82 _+ 0 .17 (20) 4 .59 _+ 0 .17 (20) ** 5 .00 +_ 0 .25 (22) 5.11 +_ 0 .19 (23) N.S.

Water 3 .80 _+ 0 . 16 (20) 4 .50 +_ 0 .13 (20) ** 3.72 _+ 0 .15 (21) 3.73 _+ 0 .13 (21) N.S.

Water & albumen 3.75 +_ 0 .15 (19) 4 .53 +_ 0 .16 (19) *** 3 .72 +_ 0 .14 (20) 3 .90 +_ 0 .15 (20) N.S.

Water & po l len - - - 3.93 _+ 0 .12 (20) 3.94 _+ 0 .09 (20) N.S.

Sugar so lu t i o n 3 .86 +_ 0 .19 (20) 4 .08 _+ 0 .16 (20) N.S. 3.52 +_ 0.11 (20) 3 .96 _+ 0 .12 (20) **

Sugar s o l n . & albumen 4.11 _+ 0 .12 (21) 4 .34 _+ 0 .14 (21) N.S. 4 .17 +_ 0 . 2 0 (24) 4 .53 +_ 0 .18 (25) N.S.

Sugar s o ln . & po l len - - - 4 .09 +_ 0 . 29 (22) 3.97 _+ 0 .19 (22) N.S.

Pooled data 3 .88 + 0 .07 (100) 4 . 40 + 0 .07 (100) *** 4 .02 + 0 . 07 (149) 4 .16 + 0 .07 (151) N.S.““

Key Data presented in form: |mean _+ S . E . (n ) |

* * s i g n i f i c a n t a t p 0 . 0 1 , * * * s i g n i f i c a n t a t p 0.001 N.S. no s i g n i f i c a n t d i f f e r e n c e

T a b le 1 .1 5 Em ergence w e ig h ts (mg) o f m ale and fem ale b e e tle s a llo c a te d to each d ie t and the

pooled d a ta fo r exp erim en ts a t 20 & 25°C .

-10

5-

4

D IE TS i gn.of

F - r a t i oNo food Water

Water & a Ibumen

Sugar

s o lu t i o n

Sugar s o ln .

& albumen

Male longev i ty (days) 2 2 . H O . 56 (20)

(18-29)

25.7^1.08 (20)

(18-40)

26 .0+0.92 (19)

(22-35)

35.4^2.54 (20)

(18-67)4 2 . H 3 . 6 2 (21)

(19-74)

***

Female logev i ty (days) A 40 .3+1.90 (20)

(31-61)

3 4 . 5_+1.38 (20)

(29-47)

4 3 . H 2 . 3 8 (19)

(30-52)

68.4^5.62 (20)

(29-130)

75 .3^6.56 (21)

(42-133)

***

D i f f . of longevi ty of males compared to unfed

group ( L . S . R . )- N.S. N.S. * *

D i f f . of longev i ty of females compared to unfed group ( L . S . R . )

- N.S. N.S. * *

C o r r e l a t i o n between male emergence weight & longev i ty

r=0.74***

r=0.03N.S.

r=0.63**

r = 0 . 24

N.S.

r=0.05

N.S.

C o r r e l a t i o n between female emergence weight & longev i ty

r=0.68***

r=0.08

N.S.

r = 0 . 16

N.S.

r=0.03

N.S.

r=0.48

N.S.

Mean No. of egg s/ lay ing female 52 .8+3.89 (20)

(23-75)

71.7+5.72 (20)

(19-104)70.6+5.55 (19)

(16-107)

7 2 . 2+4.83 (20)

(16-102)

79.6+3.71 (21)

(23-109)

*

Propor t ion of eggs hatching 0 .64+0.06 (20) 0 . 69_+0.04 (20) 0.67_+0.05 (19) 0.63^0.03 (20) 0.58_+0.04 (21) N.S .

C o r r e l a t i o n between female longev i ty & No. of eggs l a i d

r = - 0 . 18

N.S.r=-0 .68

N.S.

r = - 0 . 16

N.S.

r=-0 .44N.S.

r=-0.35N.S.

C o r r e l a t i o n between female emergence weight &

No. of eggs l a idr=0.33

N.S.r = 0 . 17

N.S.

r=0.68***

r=0.55

N.S.

r=0.24

N.S.

D i f f . of f e c u n d i t i e s on a d i e t compared to

unfed group ( L . S . R . )- N.S. N.S. N.S. *

L . S . R . l e a s t s i g n i f i c a n t range t e s tKey Data presented in form: mean +_ S . E . (n)

(Range)

* s i g n i f i c a n t a t p ^ 0 . 0 5 , * * s i g n i f i c a n t a t p 0 . 0 1 , * * * s i g n i f i c a n t a t p 0.001

N.S . no s i g n i f i c a n t d i f f e r e n c e , r Pears on ' s c o e f f i c i e n t of product-moment c o r r e l a t i o n

T a b le 1 . 1 6 E f f e c t s o f a d u lt d ie t on lo n g e v ity , fe c u n d ity & f e r t i l i t y a t 25 °C , 70% rh

-107-

The p re o v ip o s it io n p e r io d , i . e . th e p e rio d from the s t a r t o f a c t iv e

l i f e to o v ip o s it io n o f the f i r s t egg b a tc h , v a r ie d from 3-17 days

(T a b le 1 .1 7 ) . In b e e tle s d e p rive d o f fo o d , o v ip o s it io n s ta r te d

between the 4 th -6 th days o f a c t iv e l i f e , the p ro v is io n o f a d ie t

tended to in c re a s e the range o f the p re o v ip o s it io n p e r io d , b u t most

s ta r te d o v ip o s it in g between days 4 -6 .

In F ig u re 1 .21 o v ip o s it io n ra te s (eggs p e r fem ale p e r d a y ) , a re

p lo tte d a g a in s t fem ale age fo r the f iv e d ie t s . D eaths o f m ales and

fem ales a re in d ic a te d by the d e c lin in g numbers w ith in c re a s in g ag e .

F o r a l l d ie t s th e r a te o f o v ip o s it io n was a t i t s peak between days

4 - 5 , th e re a fte r fu r th e r peaks o ccu rre d to a g re a te r o r le s s e r degree

between days 9-10 and 14-17 , and fo r some d ie t s fu r th e r peaks w ere

d is c e m a b le . O n ly b e e tle s p ro v id ed w ith a d ie t c o n ta in in g sug ar

co n tin u ed to o v ip o s it a f t e r 30 d a y s , b u t a t a much reduced r a t e .

Fem ales a lw ays liv e d s ig n if ic a n t ly lo n g e r than m a le s , th e re fo re

th e d e c lin e in o v ip o s it io n r a te may p a r t ly have been due to d eath s

o f m ales (F ig u re 1 .2 1 ) . The p a ir in g o f o n ly one m ale w ith a fem ale

fo r l i f e may have re s u lte d in fe c u n d ity v a lu e s below the p o te n t ia l

fo r t h is s p e c ie s , a lth o u g h t h is has n o t been determ ined exp erim en t

a l l y .

O v ip o s it io n was o n ly observed in v ir g in fem ales p ro v id ed w ith a

d ie t w h ich in c lu d e d sug ar (T a b le 1 .1 8 ) . O v ip o s it io n was n o t re c o rd

ed u n t i l the 18 th day o f a c t iv e l i f e , and th e re d id n o t appear to

be any p a tte rn in the r a te o f egg la y in g (F ig u re 1 .2 2 ) . The mean

t o t a l fe c u n d ity v a lu e s o f 23 fo r b e e t le s fed on su g ar s o lu t io n and

52 fo r sug ar s o lu t io n & album en, w ere s ig n if ic a n t ly lo w er than the

e q u iv a le n t v a lu e s fo r mated fe m a le s .

F e cu n d ity in mated b e e t le s was l i t t l e a ffe c te d by a d u lt d i e t , o n ly

su g ar s o lu t io n & albumen re s u lte d in a s ig n if ic a n t in c re a s e compared

to unfed b e e tle s (T a b le 1 . 1 6 ) . Egg h a tch was n o t a ffe c te d by a d u lt

d i e t , the h ig h e s t reco rd ed mean h a tc h was 68.5% fo r b e e t le s fed on

w a te r o n ly , and the lo w est 57.8% fo r su g ar s o lu t io n & album en.

None o f the eggs o v ip o s ite d by v ir g in fem ales h a tch e d .

D i e t25 ° c N3 O o C

No. of

i n d lv s .

1s t day of

3 4 5 6

o v i p o s i t i o n

7 8 9 17

No. of

i nd iv s .

1s t day

3 4 5 6

of

7

ov i pos i t io n

8 9 10 11 12 13 14 15 19 20

No food 20 12 6 2 23 8 5 4 2 1 3

Water 20 2 6 7 3 1 1 21 1 2 7 3 2 1 1 1 2 1

Water & albumen 19 5 8 2 3 1 20 5 2 7 1 1 1 2 1

Water & po l len - 20 3 7 3 1 2 2 1 1

Sugar so lu t i o n 20 3 9 4 1 2 1 20 4 9 5 2

Sugar so ln . & albumen 21 8 4 2 3 3 1 25 3 5 11 3 1 2

Sugar s o l n . & po l len - 22 4 8 4 2 1 2 1

T a b le 1 .17 Frequency o f the s t a r t o f o v ip o s it io n a t 20 & 25°C , 70% rh in p a ire d b e e tle s

fed on d if fe r e n t d ie t s .

-10

8-

-109-

F ig u re 1 .2 1 Mean d a ily o v ip o s it io n r a te and s u rv iv o rs h ip o f

p a ir s o f a d u lt b e e t le s fed on d if fe r e n t d ie t s

a t 25°C , 70% rh in a 16 :8LD p h o to p e rio d .

*

#

-110-

SUG

AR

SO

LUTIO

N

oi—i

1—i—i

00 oCL►—I > o<UJ

108642

■X.

p"

rl_ - HrJl

n l~L

20161284

10 15

20 25

3 0 35

4050

60

NUMBER OF 8 & (j> BEETLES (Declining population)

[ ----- male / ------ female ]

-111-

Temp

°C D ie tNo. of

indi v s .

No. of

eggs/femaIe

Ov i pos i t-

i ng l i f e

(days )

Length of

a c t i v e

I i f e ( d a y s )

Prop.of

femaIes

ovi p o s 1ng

25

No food 10 0 - 53 .6 _+ 5 .10

(24-73)

-

Water 10 0 - 57 .0 +_ 6 .10

(26-80)

-

Water & albumen 10 0 - 55 .4 +_ 5 .68

(22-78)

-

Sugar s o lu t i o n 10 22 .8 _+ 3 .13 (0 -35)

18-57 67 .0 +_ 6 .78

(33-95)

0 .80

Sugar s o l n . & albumen 10 52.1 _+ 5.62

(0 -81)18-60 77 .3 +_ 7 .70

(39-123)

0 . 8 0

20

No food 10 7 .2 _+ 0 .34

(0 -20)21-50 64.1 _+ 5.49

(35-86)0 . 40

Water 10 10.1 _+ 0 .23

(0 -34)21-54 62.1 _+ 6.32

(31-89)0 . 40

Water & albumen 10 13.1 +_ 0 .22

(0 -32)19-53 60 .2 _+ 2.88

(47-72)0 . 50

Water & po l len 10 10.2 _+ 0 .19

(0 -36)

20-55 69.1 +_ 4 .36

(42-85)

0 .30

Sugar s o lu t i o n 10 25 .7 +_ 0.15

(0 -40)20-62 94 .6 _+ 7.24

(60-131)

0 . 70

Sugar s o l n . & albumen 10 19 .9 _+ 0 .22

(0 -37)21-63 88 .2 _+ 8 .00

(55-136)

0 . 70

Sugar s o l n . & po l len 10 20 .4 _+ 0 .29

(0 -38)

21-64 103.4 _+ 9 .38

(67-157)

0 . 90

K e y Data presented in form: mean _+ S . E .

(Range)

Table 1.18 Oviposition and longevity of virgin females at 20 & 25°C, 70% rh, fed on different diets.

MEA

N

OV

IPO

SIT

ION

R

AT

E

(Eg

gs

per

£

p

er

day

)SUGAR SOLUTION

20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62A G E -------► (D a y s)

Figure 1.22 Mean daily oviposition rate of virgin females fed on different diets at 25°C, 70% rh.

-112-

-113-

(ii) Results at 20°CThe proportions of pairs of beetles laying less than 10 eggs for the 7 diets of no food, water, water & albumen, water & pollen, sugar solution, sugar solution & albumen, and sugar solution & pollen were:25.8, 8.7, 13.0, 13.0, 16.7, 21.9 & 0.0% respectively. There did not appear to be any correlation between diet and the proportions of non laying females. No significant differences in mean emergence weight were observed between the sexes allocated to 6 of the diets and for the pooled data, only the group fed on sugar solution showed any significance, where females were heavier than males (Table 1.15). Analysis of variance showed that there was a significant difference in mean emergence weight between the 7 treatments. Both males and females allocated to the unfed group were significantly heavier than those of the other groups. Examination of the experimental procedure revealed that the pupae from which the unfed beetles were derived had been taken from the stock culture 3 weeks before those allocated to the other diets.

Provision of a diet only significantly increased the length of active life of both sexes when fed on sugar solution & albumen and sugar solution & pollen (Table 1.19). For all diets females lived longer than males. Linear correlations between emergence weight and longevity of the sexes were somewhat tentative, for males significant straight line relationships of increasing length of life with increasing weight were obtained for diets of water & albumen, water & pollen and sugar solution, and for females, water & albumen only. Linear correlation between female longevity and number of eggs laid was only found for the sugar solution diet. Correlations between female emergence weight and number of eggs laid were obtained for the unfed, water and sugar solution & albumen groups.

The preoviposition period varied from 4-20 days, with most individuals on all diets starting oviposition between days 5-6 (Table 1.17). Oviposition rates for the 7 diets are plotted against female age in Figure 1.23. Deaths of males and females are indicated by the declining numbers of beetles with time. For all treatments the peak rate of oviposition occurred between days 5-6, and apart from the unfed group 2 further peaks were evident between days 10-12 and

*

DIETS i g n . o f

F - r a t i oNo food Water

Water & a Ibumen

Water &

p o l le n

Sugar

so lu t i o n

Sugar so ln .

& albumen

Sugar s o ln .

& po l le n

Male longevi ty (days) 30.0_+0.98 (22)

(22-42)30 .3jM.57 (21)

(17-47)29 .6jM.83 (20)

(19-48)

2 9 . 7 M . 0 7 (20)

(19-38)

3 4 . 8+j2.73 (20)

(18-64)

4 4 . 2_+2.98 (24)

(17-62)

5 3 . 5_+2.86 (22)

(26-77)

***

Female longev i ty (days) 47 .5+1.83 (23) (28-62)

40 .0+1.35 (21)

(30-57)43 .0+2.26 (20)

(27-69)40.8j|j2 .10 (20)

(27-58)53.1jM.25 (20)

(29-80)6 7 . 9+j5.14 (25)

(18-124)

82.4jtj2.75 (22)

(60-119)

***

D i f f . of longevi ty of males compared to

unfed group ( L . S . R . )- N.S. N.S. N.S. N.S. * *

D i f f . of longevi ty of females compared to


C o r r e l a t i o n between male emergence weight & 1ongev i ty

r=0.40

N.S .

r=0.41

N.S.

r=0.64** r=0 .70*** r=0.52* r = 0 . 14

N.S.

r=0.05N.S.

C o r r e l a t i o n between female emergence weight

& longevi tyr=0.40

N.S.r=0.00N.S.

r=0.74*** r=0.00N.S.

r=0.03N.S.

r=0.40

N.S.

r=0.06

N.S.

Mean No. of egg s/ lay ing female 5 4 . 4 M . 1 7 (23)

(20-98)

58.OjIj3.54 (21)

(24-89)

54.2jM.11 (20)

(19-81)

59.6j|j5.21 (20)

(20-99)

62.8+4.43 (20)

(29-103)

82.5j*j5.84 (25)

(26-128)

82 .7 jM.80 (22)

(38-132)

***

Propor t ion of eggs hatching 0.70jtj0.03 (23) 0 .80+0.04 (21) 0.80j+j0.03 (20) 0.75_+0.05 (20) 0.67jtj0.04 (20) 0.65_Jj0 .03 (25) 0.70j|j0 . 04 (22) N.S.

C o r r e l a t i o n between female longev i ty & No. of eggs l a i d

r = 0 . 16 N.S .

r=0.27N.S.

r=0.28N.S.

r=-0 .73N.S.

r=0.68*** r=0.38N.S.

r=0.00N.S.

C o r r e l a t i o n between female emergence weight

& No. of eggs l a idr=0.76*** r=0.48* r=0.06

N.S.r=0.32N.S .

r=0.26N.S .

r=0.50** r=0 .40N.S.

D i f f . of f e c u n d i t i e s on a d i e t compared to


Key Data presented in form: mean + S . E .

(Range)(n)

L . S . R . l e a s t s i g n i f i c a n t range t e s t * s i g n i f i c a n t a t p 0 . 0 5 , * * s i g n i f i c a n t a t p $ 0 . 0 1 , * * * s i g n i f i c a n t a t p 0.001

N.S. no s i g n i f i c a n t d i f f e r e n c e , r Pea rs on ' s c o e f f i c i e n t of product-moment c o r r e l a t i o n

Table 1.19 Effects of adult diet on longevity, fecundity & fertility at 20°C, 70% rh

-114-

-115-

UNFED

AGE--------► (Days)

Figure 1.23 Mean daily oviposition rate and survivorship of pairs of adult beetles fed on different diets at 20°C, 70% rh, in a 16:8LD photoperiod.

MEA

N

OVI

POSI

TIO

N

RATE

(Eg

gs

pe

rn p

er

day

)

-117-

and 14-16. In the unfed group only 2 distinct peaks at days 5 & 13 were apparent. Only beetles given a diet including both sugar and protein (albumen or pollen), continued to oviposit significant numbers of eggs after the 45th day. In all cases the majority of eggs were oviposited in the first 20 days of active life.

Oviposition was observed in virgin females allocated to all the diets, including the unfed group (Table 1.18). Mean oviposition rates were significantly lower (p < 0.001) compared with mated females on the same diets. Oviposition did not commence until the 19th day and there was no obvious pattern in the rate of oviposition (Figure 1.24).

Only diets including protein significantly increased the mean total fecundity of mated females above that of unfed beetles (Table 1.19). Egg hatch was unaffected by adult diet, the highest recorded mean hatch was 80% for beetles fed on water & albumen and the lowest,65% for sugar & albumen. None of the eggs oviposited by virgin females hatched.

1.3.15 Anatomy of the female reproductive system

A . 6 a ^ n i c . u 6 has typical telotrophic-meroistic ovarioles, the characteristics of which have been described by Bonhag (1958) and Bunning (1979). Figure 1.25 shows the reproductive system of a 3 day old active adult. The paired ovaries lie against the ventral abdominal stermites. Each ovary is composed of 6 ovarioles (no departure from this number was observed in any beetles dissected), opening into the calyx which is connected to the common oviduct by a short lateral oviduct. The large muscular bursa-copulatrix opens into the junction of the common oviduct and the vagina. In the wall of the bursa there are 3 darkly coloured chitinous structures which point into the cavity of the bursa.lt is assumed that the function of these is to burst the spermatophore, releasing the spermatazoa, in a fashion similar to the signa of Lepidoptera (Hewer, 1934), indeed in one dissection a spermatophore-like body was observed in the proximal region of the bursa, and upon bursting released a mass of threadlike sperm. Leading from the bursa-copulatrix is a structure clear-

*

Figure 1.24 Mean daily oviposition rate of virgin females fed on different diets at 20°C, 70% rh.

MEA

N

OV

IPO

SITI

ON

R

ATE

(E

gg

s p

er £

per

da

y)

UNFED

n n

-120-

Figure 1.25 Diagram of the female reproductive system of A n th .s ie .m i6 6 a n .n t c .u 6 3 days after emergence from the last larval skin.

KeyBC bursa-copulatrixC calyxCO common oviductCS chitinous structures (3)DF distal follicleDSG duct of spermathecal glandG germariumL0 lateral oviduct0 ovaryOV ovariolePF proximal follicleSC spermathecal chamberSD spermathecal ductSG spermathecal glandTF terminal filamentsV vagina

-1 2 1 -

1mm

01mm

*

-122-

ly divisible into 3 regions, a long narrow duct strengthened with chitinous rings, leading to a small ovoid chamber, in turn connected to a large sac, which in some individuals occupied a large proportion of the left-hand side of the abdominal cavity. In live,mated adults, sperm were found in the duct and ovoid chamber, and it is presumed that these structures are the spermathecal duct and spermathecal chamber respectively. The large sac-like structure is believed to be the spermathecal gland. Typically in the Dermestidae the spermathecal gland is relatively small or absent, the reason why this species has such a large gland has not been ascertained.The general organisation of the spermathecal system is similar to that of T t io g o d o j im a . described by Surtees (1961).

1.3.16 Ovarian development

The physiological stages of ovarian development are summarised diagrammatically in Figure 1.26, and the ovary, ovariole and egg measurements illustrated graphically in Figure 1.27.

In 0-1 day old quiescent adults, there were no distinct follicles, the germarium appearing undifferentiated. At 2-4 days 1 or 2 early stage follicles were apparent, and at 7-8 days, i.e. just prior to the start of the active adult period, a chain of up to 3 developing oocytes in each ovariole could be identified. The first oocyte by this time had changed in appearance from translucent white to a denser white colour, no doubt due to yolk deposition (vitellogenesis). Clearly the major part of the maturation process occurred during the period of quiescence, by the time the active adult emerged from the last larval skin the primary oocyte had reached almost full

* maturity. After 3 days into the active period this oocyte had attained full size with chorionic development complete, and a chain of up to four oocytes at different stages of development in each ovariole was apparent, with the second and third oocytes developing rapidly. During the maturation process the ovaries increased greatly in size (Figure 1.27), and by day 3 occupied a major part of the abdominal cavity. By day 4 ripe oocytes had moved from the ovarioles to the calyces and oviducts. It would appear from the fecundity experiments described in Section 1.3.14, that 1-3 oocytes

»

Figure 1.26 Chronological stages of ovarian development inA. 6CL>uvLc.u.tl at 20°C, 65% rh.

(a) 0-1 day old quiescent adult or sterile active adult (STAGE 0).

(b) 2-4 day old quiescent adult.(c) 7-8 day old quiescent adult or 1 day old active

adult.(d) 3 day old active adult (STAGE 1).(e) 4 day old active adult (STAGE 2).(f) 6-9 day old active adult (STAGE 3).(g) 36 day old active adult (STAGE 4).

Scale bar represents 0.5 mm.

-124-

Quiescent — ► — Active adultadult AGE .Days.

Figure 1.27 Lengths of ovary, ovariole and proximal oocyte during ovarian development at 20°C, 65% rh. Error bars indicate 95% confidence limits.

ii— N3 Ln I

-126-

are matured per ovariole before oviposition takes place, as one female may lay up to 31 eggs on day 5. By days 6-9 most females had laid their first batch of eggs: oviposition was characterised by distention of the calyces and lateral oviducts and the presence of opaque yellowish ’’corpora lutea" material in the ovariolar pedicels, although these appeared to breakdown fairly rapidly in beetles developing further batches of eggs. It was not possible to determine the number of ovarian cycles completed, but distention of the intima meant that a nulliparous ovary could be distinguished from a parous ovary. In old females which had completed oviposition the ovarioles were degenerate, occasionally containing small numbers of undeveloped oocytes and the calyces and ovarioles were distended.

For the most part development of individual ovarioles was synchronous, although occasional ovarioles in an ovary appeared to be developing at a slower rate or appeared sterile. Infrequently active adults were found to have ovaries similar in appearance to the 0-1 day old quiescent stage, these were considered to be sterile.

From a consideration of the dissection results it was possible to score the stages of ovarian development in active adults on an arbitrary scale from 0-4. The different categories were:STAGE 0 Germarium undifferentiated (Figure 1.26a).STAGE 1 Presence of mature oocytes in the ovarioles, calyces and

oviducts not distended, i.e. pre-first egg batch ovulation (Figure 1.26d).

STAGE 2 Mature oocytes in the calyces and oviducts, i.e. ovulation (Figure 1.26e).

STAGE 3 Calyces and oviducts distended, corpora lutea may be present,i.e. ovulated at least 1 batch of eggs (Figure 1.26f).

STAGE 4 Ovarioles degenerate, calyces and oviducts distended, i.e. post- oviposition (Figure 1.26 g).

Stages of ovarian development are ranked according to age class in Table 1.20. It is apparent that changes in the ovaries are age dependant. In virgin females, ranked using the same scale (Table 1.20), it can be seen that these tend to retain their eggs and do not ovulate until a late stage.

-127-

Ovary ranking s c a l e Median f a tAge N o . d i s - Median Propor t ion body s i z e

Condi t ion (days) sected 0 1 2 3 4 stage with sperm & ~ange()MATED 0-2 10 10 1 .00 4 (4)

3 10 1 9 1 .40 3 (3 -4 )4 10 7 3 1 .90 3 (3 -4 )6 10 4 3 3 2 .80 2 . 5 ( 2 - 3 )9 10 1 2 7 3 .70 2 (2 -3 )

12 10 3 7 3 .70 2 (1 -3 )15 10 1 2 6 1 3 .80 2 (1 -2 )18 10 1 7 2 3 .60 1 (1 -2 )21 10 1 8 1 3 .40 1 (1 -2 )29 9 5 4 3 .11 0 (0 -2 )36 9 9 4 .11 0 (0)

VIRGIN 6 10 10 1 - 4 (3 -4 )9 10 8 2 1 - 4 (3 -4 )

20 10 6 2 2 2 - 3 (2 -3 )

Table 1.20 Stages of ovarian development, mating condition and size of fat body for mated and virgin females of different age classes, kept at 20°C, 70% rh, 16:8LD photoperiod.

-128-

Whether or not successful copulation had taken place could easily be detected by light microscopy, from the shimmering of the mobile thread-like sperm in the spermatheca. The proportions of females with sperm are indicated in Table 1.20. In addition to age-related changes in the reproductive system it was observed that the extent of the abdominal fat body decreased with increasing age (Table 1.20). In virgin females the fat body decreased in size at a slower rate than mated females.

1.3.17 Dissection of field collected beetles

Data are tabulated in detail in Appendix IV, and summarised in Table 1.21. This shows the yearly totals and means of observations for each trap site. Fewer beetles were dissected than caught because some were damaged when removed from the sticky-traps. Others,which had died on the traps, had become desiccated to such an extent that it was not possible to differentiate the abdominal organs, even after attempts to rehydrate the viscera with Ringer's solution.

Generally males were significantly shorter than females (p < 0.01), although in individuals collected from flowers there was no difference, possibly because of the small sample size (n=27). The histograms of numbers of males amd females caught on the traps each week, show that males become flight active earlier, and possibly emerge earlier than females (Figure 1.28). These differences were significant (p < 0.001) for the Entomology Building and General Herbarium traps, but not for the outdoor traps where activity was more strictly regulated by prevailing weather conditions (see Section 1.3.2).

The conditions of the ovaries and size of the fat body were similar for beetles collected from all the trap sites. In females ovaries averaged the stage 3 condition, and generally there was little fat body in the abdominal cavity. 40-50% of those dissected had sperm stored in the spermatheca. In males the fat body size averaged the stage 2 condition (based on female ranking scheme), and was significantly larger than that of females (p < 0.001). This was not true for beetles collected from flowers however, where there was no significant difference. Again this is probably a reflection of the small sample size collected.

«ft

No. Body length (mm)

caught I M (n) F (n)

A v . f a t body s i z e

M (n) F (n)

Entomology Building sticky-traps

No. d i s s e c t e d with

pol len in gut contents

<%) (36) T o t a l U )

Av .ovary

s tage (n)

No.of females

with sperm

(n ) (%)

531 3 . 0 (270) 3.1 (246)

_+ 0.02 +_ 0.02

2 .2 (270)

+ 0.05

General Herbarium sticky-traps

1.4 (256)

+ 0.05

18 ( 6 . 7 ) 33 (1 2 . 9 ) 51 ( 9 . 7 ) 3 . 0 (248)

+ 0 .07107 (253) (4 2 .3 )

840 2 . 9 (454)+ 0.02

3 . 0 (339)+ 0.02

1 .9 (463)

+ 0.05

1 .0 (356)

+ 0.05

Outdoor sticky-traps

3.1 (331)

+ 0 .06

146 (356) (4 1 .0 )

232 3 . 0 (113)

+ 0 .033.1 (110)+ 0.02

1.8 (116)

+ 0 .061.1 (115)

+ 0.05

49 (4 2 . 2 ) 40 (3 4 . 8 ) 89 (3 4 . 8 ) 3 .2 ( 98)

+ 0 .06

43 (109) ( 3 9 . 5 )

Collected from flowers27 2 . 9 ( 11)

+ 0 .083 . 0 ( 16)

+ 0 .071.0 ( 11)

+ 0.101.1 ( 16)+ 0.10

11 ( 100) 13 (8 1 .3 ) 24 (8 8 . 9 ) 2 . 8 ( 16)

+ 0 .09

8 ( 16) (5 0 . 0 )

Table 1.21 Summary of dissection data for A. 4a'ou.cu4 beetles collected at four sites at the BM(NH) during the 1983 field season.Key M = male, F = female , n = number of b e e t l e s , + = + s tandard e r r o r .

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Figure 1.28 Histograms of numbers of male and female A .6 a > u v L c u .6

caught each week at the three trap sites at the BM(NH) in 1983.

ENTOMOLOGY HERBARIUM OUTDOOR

COLLECTION DATE

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Almost 90% of beetles collected from flowers had pollen in their gut contents. In many of these the foregut was grossly distended with pollen. Only 35% of those collected from outdoor sticky-traps had fed. This may indicate that a proportion of the beetles were making their way to flowers for the first time, not having previously fed. 10% of beetles caught at window sticky-traps in the Entomology Building had pollen in their alimentary tracts. In the majority of these the only traces of pollen to be found were in the hind gut. By comparison with beetles collected from flowers where the gut was distended with pollen, it seems probable that these beetles had fed some days prior to capture and were attempting to escape outdoors again to feed. The presence of pollen fed adults in the Entomology Building corresponded with the peak period of activity of beetles outdoors, suggesting that their was a fairly free exchange of beetles between the indoor and outdoor environments. None of the beetles collected in the General Herbarium contained pollen in their alimentary tracts.

Poolingthe totals of males and females dissected from each trap site, the numbers were 866 and 746 respectively. The sex ratio was therefore 1.2 males : 1 female, which differed significantly from a 1:1 ratio (X2 > p < 0.05), assuming that the sexes were caught with equal efficiency by the traps.

*

*

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1.4 Discussion 1.4.1 Ecology of A.-6cl>iy u .c. ll4

It is probable that A. 4a> in X ,c .u .6 is inhabiting dry birds' nests in southern England, but the fact that larvae were not found in pigeon nests is not surprising, and suggests that its habits are similar to A.veA6a4cL. Woodroffe (1953) found that only 10% of feral pigeon (C o lu m b a . IX ,v Xj i ) nests harboured A.ve'i6a4cX, whereas about 60% of sparrow (Pa44e'i d o m t A t X j L i u ) , house martin ( S £ u >iywl6 vulI qcl>i Xj > ) and swallow (H X ju in d o s u i A t X jL a ) nests were infested. The reasons why A n £ k > ie ,v iu 4 spp., are seldom found in pigeon nests is not known, but may be due to competition from other nidicoles or to the high humidity which exists within the large masses of guano which form the basis of these nests. A more extensive nest survey than time permitted in the present study would be needed to ascertain the extent of sparrow nest infestation by A. 4a/uu,cti4.

During the warmer summer weather A .6 a ^ ,n X ,c u 6 adults were found feeding on the same types of flowers as recorded for A .ve,> ib cL 6e.X . (Blake, 1955). The flight activity recorded by the outdoor traps indicates that the two species are similar in this respect also, except A.4a'uaLctx4 activity continued until mid-September, whereas A.veA6a4cL activity tended to cease at the end of July (Blake, 1958). The fact that A.4a nXca4 was not found on flowers in other areas of south west London may indicate that this species is still only locally distributed. Alternatively the BM(NH) population may be unusually high because of the abundance of bird nesting sites on the building and widespread infestation within the building itself. Where suitable habitats are more diffuse, as one would expect in domestic premises, then populations are likely to be smaller and the chances of finding beetles on flowers proportionately less. Inspection of flowers at sites other than the BM(NH), were usually brief, and clearly a more systematic approach would be needed to determine its true distribution in the London area. Confirmed records suggest that A . a c u iy iL c. u.6 is fairly widespread in London and the record from Liverpool shows that its distribution is spreading in the U.K.The small number of notified records is probably because both adult and larval stages are relatively small and not readily distinguish

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able from other 'carpet beetles', and concern over such insects is not usually raised until significant damage to commodities has been found.

The trapping data have shown that A.4a Kw,c«i4 was present throughout the museum and was flying in the grounds during the summer months. Peak catches were generally correlated with rises in mean outdoor temperature, which is not surprising as the majority of insects in temperate climates are most flight active during warm sunny weather. Indoors A.uc^6a4cX adults tend to emerge earlier, i.e., from mid March compared to early May .for A . 6 a ^ y U , c . a 6 , but the former is not found at windows after late July, while the latter is found until early October. In the Entomology Building in 1983, A .A a t u v L c u A

beetles were caught at windows earlier in the year, this was believed to have been due to the installation of a new central heating system in March of that year. This caused the room temperature to rise dramatically, possibly providing a cue for larvae to pupate, resulting in a flush of adults in late April. Very many adults were collected at some windows, but attempts to find the source of infestations, which must have been large to yield so many adult beetles, were unsuccessful. Almost certainly some emerged from collection material, but generally larval damage was diffuse and could not explain the large numbers of adults caught in the General Herbarium for example, where significant damage to plant materials by A n t lv ie .n u .6 has not been recorded. Examination of roof voids, crevices and under cabinets where dust had accumulated did not reveal their presence in any number, but clearly a systematic search of the museum should be undertaken to identify and eliminate these sources, as far as is practicable.

1.4.3 Egg development

It would appear that the temperature conditions experienced by ovipositing adults affects subsequent egg hatch in A . 6 a n . t v i c . a 6. This phenomenon was also observed by Coombs & Woodroffe (1983) working on the same species. It is possible that suboptimal temperatures experienced by adult beetles decreased sperm viability resulting in increased infertility, an occurrence which is not uncommon in insects (Engelmann, 1970). A second possibility, which cannot be ruled out, is the different procedure adopted for the collection of eggs between the two groups. Where eggs were incubated in the conditions experienced by the adults, eggs were collected from pairs of beetles for the duration of the females ovipositing life, and therefore the proportion hatching represented an average for the total egg load collected from females confined with a single male. Where adults were kept at 20°C and eggs transferred to the experimental conditions eggs were collected from mixed groups of males and females, therefore the likelihood of successful mating and sperm transfer was much greater. As it has not been determined whether multiple mating is necessary to attain maximal egg fertility and realised fecundity, the confining of one male with one female for life may have resulted in reduced fertility and therefore egg hatch. It is not clear what proportion of the failure of eclosion is due to egg mortality and what is due to infertility of eggs. The egg hatch results of the present investigation differ from those of Coombs & Woodroffe in that egg hatch was recorded up to 32.5°C (although only at 70% rh), and the proportions of eggs hatching were consistently higher over the whole temperature range. Coombs considered that the low egg hatch recorded in their investigation was due to mishandling of eggs.

1.4.3 Larval development

For the majority of larvae reared in constant temperature-humidity conditions above 15°C, the developmental period was circannual, with the bulk of the pupations occurring between weeks 38-60. At 15°C pupation was bimodal, with the first group pupating in the circannual time interval and the second at 90-108 weeks, indicating that at

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low temperatures a proportion of the population may undergo semivoltine development. At all temperatures a few larvae pupated at infrequent intervals after the 'mean' period, resulting in skewness in the distribution of pupation frequencies. Similar results were obtained by Coombs & Woodroffe (1983), although at 15°C they recorded two larvae pupating at 153 and 168 weeks, which they considered might be indicative of a 3 year developmental period which would have been clearer if larger numbers of replicates had been used for the experiment. Also they did not observe any successful pupations at 30°C, 65% rh, in the present study 53% of larvae survived to pupation at this temperature-humidity combination. A . v & i b a 4 c . j L

also pupates with a uni- or bi-modal pupation frequency in constant conditions, the proportions pupating in each interval being dependant upon temperature conditions experienced by the developing larvae.At temperatures above 20°C all larvae pupated in the first period and below 17.5°C in the second period, at intermediate temperatures pupation was bi-modal (Blake, 1958).

Extremely early pupation was recorded in a small proportion of the larvae reared at 25°C, 70% rh. This had not been encountered by Coombs & Woodroffe from whose cultures the PICL stock used in the present study were derived. The earliest pupation noted by the previous authors was 37 weeks at 25°C, 70% rh. The possibility that reduced larval period had somehow been selected for by the culturing methods in the intervening 10 years between the previous study and the present work is possible, although similar pupation periods were recorded in larvae from stock comprising 'wild' specimens from the BM(NH), which had been cultured for only one year. All other temperate A Y ith t ie n u .6 species whose biologies have been described, have circannual or longer life cycles. If reduced larval periods can occur in A . 6 olsiyu.c u .4 under normal environmental conditions, then the increased pest potential of this species is clearly evident.

Larval development in constant conditions was characterised at most temperature-humidity combinations by a regular moulting cycle for the first 5-7 instars, followed by an extended instar duration during the 6th, 7th or 8th instar, persisting for up to 40 weeks. After this period of reduced developmental activity some larvae pupated directly

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w h ile o th e rs underwent fu r th e r re g u la r m oults b e fo re p u p a tio n . These

p e rio d s o f deve lopm ental in a c t iv i t y have been co n sid e re d to be

p e rio d s o f d iap au se in A .vdn .bcL6c.Ji (B la k e , 1 9 5 8 ). L ik e w is e , the

p o t e n t ia lly e x tre m e ly long la r v a l d iap au se o f T n .o g o d o .n .m a g n .a n a rd u u m

E v e r t s , i s a s so c ia te d w ith extended p e rio d s o f in a c t iv it y ,in f r e q u e n t

m o u ltin g and h id in g in a c re v ic e (B u rg e s , 1 9 5 9 ). In tem perate

D ic ty o p te ra extended in s t a r d u ra tio n h as been used as a c r it e r io n

to in d ic a te the o ccu rren ce o f nym phal d iap au se (B ro w n , 1 9 8 0 ). S im p le

q u ie sce n ce i s an u n lik e ly e xp la n a tio n fo r th ese p e rio d s o f extended

developm ent in A . 6 cl>iy iL c. u.6 because by d e f in it io n t h is phenomenon i s

a s s o c ia te d w ith a d ir e c t re sp o n se to d e le te r io u s p h y s ic a l c o n d it io n s

w h ich i s te rm in ated when e n v iro n m en ta l c o n d it io n s re tu rn to the

b io lo g ic a lly a cce p ta b le range (B e c k , 1 9 8 0 ). In th e p re se n t stu d y

c o n d it io n s w ere kep t co n sta n t fo r the d u ra tio n o f the e xp e rim e n ts ,

th e re fo re th e re i s l i t t l e doubt th a t the extended in s t a r d u ra tio n s

a s so c ia te d w ith m ature la rv a e a re p e rio d s o f d ia p a u se .

In most ca se s d iap au se appeared to be o b lig a to ry , a lth o u g h the

r a p id ly d eve lo p in g la rv a e d e sc rib e d above , pupated a f t e r o n ly 5-6

in s t a r s w ith o u t undergoing an o b vio us p e rio d o f d iap au se developm ent,

and s t i l l o th e r la r v a e , p a r t ic u la r ly a t h ig h tem p era tu re -h u m id ity

co m b in atio n s underwent numerous m ou lts w ith o u t an o b vio us extended

in s t a r p e r io d . These d iffe re n c e s in developm ent may however be an

e x p re ss io n o f d if f e r e n t in t e n s it ie s o f d ia p a u se . T . g f ic m a f i J iu m fo r

exam p le , e n te rs d iap au se a t tem p eratu res below 30°C and w h ile in

d ia p a u se , la rv a e move ab o u t, feed and may even m o u lt, b u t th ey have

a low ered m e ta b o lic ra te and do n o t com plete grow th and developm ent.

An in c re a s e in tem peratu re r e s u lt s in the te rm in a tio n o f d iap au se

su g g e stin g d iap au se to be o f low in t e n s it y , b u t some la rv a e may

rem ain in d iap au se fo r up to 8 y e a r s , su g g estin g a v e ry in te n se

d iap au se (B u rg e s , 1960, 1 9 6 2 ).

D iapause developm ent in c o n sta n t c o n d it io n s was o n ly e v id e n t in

m ature la r v a e , u n lik e A . v t i b a t c i . , w here a t tem peratu res below 20°C

la rv a e underw ent two d iap au se p e r io d s , f i r s t l y as 2nd-3rd in s t a r s

and then as m ature la r v a e , on co m p letio n o f w h ich they p up ated . A t

tem p eratu res above 20°C la rv a e d iap aused o n ly as m ature la rv a e and

a t 1 7 .5 °C the b eh av io u r was in te rm e d ia te , w ith some la rv a e co m p leting

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developm ent a f t e r one d iap au se p e r io d , o th e rs re q u ir in g two (B la k e ,

1 9 5 8 ). B la k e (u n p u b lish e d ) co n sid e re d th a t g ro w th , d iap au se and

p u p atio n in A .v e s ib a 6 c . i . a re coup led to a s in g le endogenous, c i r c -

an n u a l c lo c k . P u p atio n was shown to o ccu r in up to 3 groups spann ing

about 21 weeks and 42 weeks a p a rt from each o th e r . T h is p e r io d ic it y

was m a in ta in ed a t co n sta n t tem p era tu re -h u m id ity co m b in atio n s between

14 and 2 5 °C , a t 30 and 70% r h , and was th e re fo re tem peratu re compen

s a te d . Such a p re c is e rhythm o f developm ent does n o t appear to be

th e ca se in A .6 a n .y iic .u 6 as in d ic a te d by the w ide sp read in p u p atio n

fre q u e n c ie s o ver the range o f co n sta n t c o n d it io n s s tu d ie d .

The exp erim en ts conducted in a p igeon lo f t have shown th a t A . 6an.yuic.a6

i s cap ab le o f d eve lo p in g s u c c e s s fu lly in outdoor ( a lb e it s h e lte re d )

c o n d it io n s in so u th ern En g lan d . A d u lt b e e tle s a re found outdoors

from May to Septem ber, th e re fo re la rv a e h a tch in g from eggs la id

in s u ita b le outdoor h a b ita ts w i l l emerge from June to Septem ber.

The p ro p o rtio n s o f th ese ta k in g 1 o r 2 y e a rs to deve lo p w i l l depend

on th e tim in g o f emergence and tem peratu re c o n d it io n s d u rin g the

a c t iv e la r v a l growth p e r io d s . L a rv a e h a tch in g from eggs la id e a r ly

in the season grow s u f f ic ie n t ly to d iap au se d u rin g the w in te r as

m ature la rv a e w h ich pupate the fo llo w in g sp rin g o r summer. Those

h a tc h in g la t e r on in the season a re g e n e ra lly s e m iv o lt in e , p a ss in g

th e f i r s t w in te r in the e a r ly in s t a r s ta g e . Growth and developm ent

resum es as soon as fa v o u ra b le c o n d it io n s re tu rn around mid May.

M o u ltin g ce ase s a t about mid O ctober and d iap au se developm ent con

tin u e s u n t i l th e resum ption o f fa v o u ra b le c o n d it io n s around May

th e fo llo w in g y e a r when p u p atio n ta ke s p la c e .

Pho to p erio d a ls o appeared to be h a v in g an e f fe c t upon v o lt in is m .

* When la rv a e w ere re a re d in n a tu ra l p ho to p erio d s under outdoor

c o n d it io n s , th e p ro p o rtio n o f u n iv o lt in e in d iv id u a ls was g re a te r

than those in co n sta n t d a rk . T h is was n o t tru e fo r la rv a e em erging

in August and Septem ber ho w ever, where the sh o rt fa v o u ra b le d eve lo p

ment p e rio d n e c e s s ita te d la rv a e to o v e rw in te r as e a r ly in s t a r la rv a e

re g a rd le s s o f p h o to p e rio d ic c o n d it io n s . They then re q u ire d a second

a c t iv e season o f grow th b e fo re d iap a u s in g as m ature la rv a e and

p u p atin g the fo llo w in g s p r in g . The p h o to p e rio d ic in flu e n c e on la r v a l

developm ent was more obvious in la rv a e re a re d in the la b o ra to ry

under n a tu r a lly f lu c tu a t in g c o n d it io n s , where se a so n a l tem peratu re

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v a r ia t io n was n o t as extrem e . B a tch es re a re d in co n sta n t d a rk a l l

pupated w ith a p p ro x im a te ly the same la r v a l p e rio d o f 41 w eeks, w h ile

in la rv a e re a re d in n a tu ra l p h o to p erio d the tim in g o f p u p atio n

depended upon th e tim e o f y e a r la rv a e h a tch e d . D iffe re n c e s a ls o

e x is te d in the in t e n s it y o f d iap a u se ; in co n sta n t d a rk the d iap au se

sta g e was a lw ays the 6 th , 7 th o r 8 th in s t a r , and th e d u ra tio n o f

d iap au se was g e n e ra lly o f s h o rte r d u ra tio n than th a t o f t h e ir

c o u n te rp a rts in n a tu ra l p h o to p e rio d . In n a tu ra l p h o to p erio d d eve lo p

ment was c h a ra c te r is e d by ra p id grow th and re g u la r m o u ltin g u n t i l

m id O ctober when most la rv a e ceased m o u ltin g and underw ent a p e rio d

o f d iap au se developm ent, th e s t a r t o f w h ich was c o in c id e n t w ith the

autum nal phase o f d e c re a s in g p h o to p erio d and to a le s s e r e x te n t temp

e ra tu re . In c re a s in g d ay le n g th and a s l ig h t u p tu rn in tem peratu re

in Ja n u a ry re s u lte d in a resum ption o f m o u lting and a l l in d iv id u a ls

pupated in the p e rio d Feb ru a ry -Ju n e re g a rd le s s o f the month in the

p re v io u s y e a r th a t la r v a l l i f e began.

C le a r ly la rv a e in co n sta n t d a rk w ere d eve lo p in g in a 'p red e te rm in ed '

rhythm w ith the o n se t o f d iap au se developm ent o n ly o c c u rr in g in

m ature la r v a e . T h is rhythm was n o t in flu e n c e d to any g re a t e x te n t

by s e a s o n a lity because tem peratu re f lu c tu a t io n s in the room through

o u t the y e a r w ere r e la t iv e ly s m a ll. P ho to p erio d m o d ifie d th e d eve lo p

m enta l rhythm ; d e c re a s in g ph o to p erio d re s u lte d in la rv a e d iap a u sin g

a t w h atever in s t a r had been reached a t th a t p o in t in tim e and in

c re a s in g p h o to perio d re s u lte d in th e resum ption o f developm ent and

subsequent p u p a tio n . Where se a so n a l tem peratu re v a r ia t io n s a re

e xtre m e , as in th e p igeon l o f t , tem peratu re i s an im p o rtan t o v e r

r id in g fa c to r upon developm ent. Hence th e developm ent o f la rv a e in

co n sta n t d a rk d id n o t d i f f e r m arked ly from those e x p e rie n c in g n a tu ra l

♦ p h o to p erio d e xce p t in the p ro p o rtio n s ta k in g 1 o r 2 y e a rs to com plete

developm ent. B la k e (1 9 6 0 ) determ ined th a t under outdoor c o n d it io n s

tem peratu re was th e im p o rtan t fa c to r c o n t ro llin g the tim in g o f

p u p atio n in A .vo ,n .b cuc.jL , l ig h t d id n o t appear to p la y any p a r t .

In te ra c t io n between p h o to p e rio d ic and th erm al e f fe c t s on d iap au se

i s w e ll known, indeed d iap au se developm ent i s a tem peratu re s e n s it iv e

p ro c e s s , where th e e f fe c t iv e tem peratu re i s much lo w er than temp

e ra tu re s a f fe c t in g non-d iapause m orphogenesis (B e c k , 1 9 8 0 ). Tauber

& Tauber (1 9 7 6 ) suggested th a t the tem peratu re th re sh o ld fo r d ia

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pause developm ent i s low a t the b eg in n in g o f d ia p a u se , r is in g as

d iap au se p ro ce e d s . When the d iap au se developm ent th re sh o ld r is e s

and re ach es th e th e rm al th re sh o ld fo r m orphogenesis, d iap au se de

velopm ent ce a se s and the in s e c t resum es non-d iapause d if f e r e n t ia t io n

a s en v iro n m en ta l tem peratu res d ic t a t e .

In exp erim en ts w ere la rv a e w ere re a re d in co n sta n t c o n d it io n s o r

f lu c tu a t in g c o n d it io n s in the la b o ra to ry , d iap au se was o n ly o b se r

ved in m ature la r v a e . In the p igeon l o f t , la rv a e in tro d u ce d to

th e se c o n d it io n s in the autumn o ve rw in te re d as 2nd in s t a r la r v a e ,

w hether th ese w ere d iap a u sin g o r s im p ly in a s ta te o f q u ie scen ce

was no t known. Brown (1 9 8 0 ) found th a t 2nd in s t a r nymphs o f the

co ck ro a ch , E c .t o b i .u 6 poJUUidu.6 ( O l i v . ) , o ve rw in te re d by q u ie sce n ce ,

w h ile 3rd o r 4 th in s t a r s showed a d u a l type o f re sp o n se , some e x

h ib it in g q u ie sce n ce and o th e rs d ia p a u se . I t was co n sid e re d th a t

th e se la t e in s t a r nymphs underw ent a p e rio d o f d iap au se developm ent

a f t e r w h ich th ey rem ained q u ie sc e n t u n t i l en v iro n m en ta l c o n d it io n s

became fa v o u ra b le fo r p o st-d ia p au se developm ent.

In c re a s in g p h o to p erio d a t co n sta n t tem peratu re induced la rv a e to

pupate w ith o u t undergo ing a p e rio d o f d iap au se developm ent. Most

in d iv id u a ls pupated a f t e r 5 in s t a r s , w h ile in co n sta n t d a rk d iap au se

developm ent o ccu rre d in the 6 th o r 7 th in s t a r a f t e r w h ich p u p atio n

to o k p la c e . U n fo rtu n a te ly i t was n o t p o s s ib le to in v e s t ig a te the

e f fe c t s o f d e c re a s in g p h o to p e rio d s , o r to d eterm ine the s e n s it iv e

sta g e in the la r v a l l i f e d e te rm in in g d iap au se developm ent. A l

though A . 6dn.nJuc.a6 la rv a e respond to in c re m e n ta l changes in photo

p e r io d , the re sp o n se may have been due to a c r i t i c a l d ay le n g th

e xp e rie n ce d d u rin g a s e n s it iv e phase t r ig g e r in g p u p atio n /n o n -d iap au se

developm ent. A cco rd in g to Tauber & Tauber (1 9 7 8 ) th e re a re e s s e n t ia lly

th re e typ es o f s tim u lu s-re sp o n se p a tte rn s re g u la t in g m aintenance

o f in s e c t d iap au se in n a tu re :

[1 ] a l l o r n o th in g respo nse to a c r i t i c a l p h o to p e rio d ,

[2 ] graded resp o n se in r e la t io n to a b so lu te d ay le n g th d u ra t io n , o r ,

[3 ] resp o n se to the g ra d u a l se a so n a l change in d a y le n g th .

In A .v e .> ib a 6 c .t th e s e n s it iv e phase fo r u n iv o lt in e in d iv id u a ls i s

th e f i r s t 13 weeks o f la r v a l l i f e . When p ro v id ed w ith c o n d it io n s o f

n a t u r a lly in c re a s in g pho to perio d d u rin g th is tim e , la r v a l p e rio d was

- 141-

d ecreased compared w ith c o n tro ls in co n sta n t d a rk . T h is resp o n se

how ever may h ave been due to a c r i t i c a l pho to perio d exp e rie n ce d

d u rin g the in c re a s in g d a y le n g th s . Subsequent changes in ph o to p erio d

a f t e r 13 weeks d id n o t a f fe c t the r a te o f developm ent. The c o n tro l

o f s e m iv o lt in e in d iv id u a ls was determ ined d if f e r e n t ly and was la rg e ly

under the im m ediate c o n tro l o f en v iro n m en ta l l ig h t c o n d it io n s , w ith

d e c re a s in g p h o to p erio d in h ib it in g m etam orphosis (B la k e , 1960; 1 9 6 3 ).

D iapause i s an im p o rtan t a d a p tiv e s tra te g y in in s e c t s , p a r t ic u la r ly

in tho se w ith one o r le s s g e n e ra tio n s p e r y e a r . D in g le (1 9 7 8 )

s ta te d th a t d ia p a u se , "p e rm its escape in tim e , b u t a ls o in te r a c t s

w ith developm ent ra te s to sy n ch ro n ise l i f e c y c le s , d eterm ine p a tte rn s

o f v o lt in is m and g e n e ra lly re g u la te se a so n a l p h e n o lo g ie s" . I t has

a lre a d y beenshown th a t d iap au se re g u la te s se a so n a l emergence o f

a d u lt A . 4 a ' i v u , c t i 4 , th e reb y in c re a s in g the chances o f m ating in an

in s e c t w ith w id e ly s c a tte re d , low d e n s ity p o p u la tio n s . The a d a p tive

advantage o f po lym odal em ergence p a tte rn s have been d iscu sse d by

W aldbauer (1 9 7 8 ). M o d a lity in A . 6 a n . n J i ( n i 6 i s e s s e n t ia lly f a c u lt a t iv e

depending upon the season in w h ich the eggs h a tch and the tem peratu re

c o n d it io n s e xp e rie n ce d by la rv a e d u rin g the grow ing seaso n . The

a d a p tiv e v a lu e o f p ro p o rtio n s o f th e p o p u la tio n ta k in g one o r two

y e a rs to d eve lo p has been co n sid e re d by G r i f f i t h s (1 9 5 9 ) in r e la t io n

to sa w fly la r v a e . He co n sid e re d th a t la rv a e p a ss in g through one o r

two o v e rw in te rin g p e rio d s b u ffe rs th e p o p u la tio n a g a in s t the c a ta

s tro p h ic e lim in a t io n o f an e n t ir e y e a r c la s s . Indeed many in s e c ts

w ith po lym odal emergence p a tte rn s a re a s so c ia te d w ith m a rg in a l a re a s

w here c o n d it io n s tend to v a ry u n p re d ic ta b ly from y e a r to y e a r . As

th e n a tu ra l h a b ita ts o f A . 6 a > i r u . c . u . 4 a re n o t known a t p re se n t i t i s

n o t p o s s ib le to p re d ic t i f i t f a l l s w ith in t h is ca te g o ry o f phen-

o lo g ic a l a d a p ta tio n .

A. 4 c lk.y l l c .il6 i s cap ab le o f s u c c e s s fu l la r v a l developm ent on a w ide

range o f d r ie d an im a l m a te r ia ls . In museums t h is sp e c ie s co u ld

m a in ta in i t s e l f on m a te r ia ls d e riv e d from an im a l p ro d u cts and in

b ir d s ' n e s ts in ro o f v o id s , o r even d u st and d e b ris w h ich accumu

la te s under c a b in e ts , flo o rb o a rd s e t c . P la n t m a te r ia ls a re n o t

s u ita b le fo r com plete developm ent, b u t acco rd in g to Peacock (p e r s .

comm.) la t e in s t a r la rv a e have been noted to damage h erb ariu m

sp ecim en s, a lth o u g h th is may re p re se n t e x p lo ra to ry fe ed in g o n ly .

- 142-

One la r v a was reco rd ed as h a v in g eaten through a ce llo p h a n e p ack e t

c o n ta in in g seed specim ens b u t no fu r th e r damage was n o ted . In con

t r a s t la rv a e o f A .veA6adcX can com plete developm ent on p la n t m ater

i a l s . F o r exam p le , C h itten d en (1 8 9 5 ) showed th a t la rv a e w i l l feed on

a w ide range o f p ro cessed ve g e ta b le d e riv e d fo o d s tu ffs , in c lu d in g

f lo u r and c a k e s , and F e lt (1 9 0 9 , 1 9 1 9 ), d e sc rib e d a c u ltu re w h ich

su rv iv e d fo r 17 y e a rs in a j a r c o n ta in in g o n ly two e a rs o f m a ize .

1 .4 .4 F e c u n d ity and o v ip o s it io n

The r e s u lt s o f o v ip o s it io n a t d if f e r e n t tem peratu res were com parab le

w ith tho se o f Coombs & W oodro ffe , e xce p t th a t in th e p re se n t stu d y

fe c u n d ity was h ig h e r a t tem p eratu res o th e r than 15 °C . T h is was

s u rp r is in g because they a llo w ed b e e tle s p e r io d ic a cce ss to sug ar

s o lu t io n w h ich i s known to bo o st egg o utp ut (S e c t io n 1 .3 .1 4 ) , w h ile

in t h is stu d y b e e tle s were unfed fo r the d u ra tio n o f a d u lt l i f e .

L ik e many members o f the D erm estidae A . 4a .tiYu .cu4 i s autogenous.

Unfed fem ales w ere cap ab le o f la y in g 66% o f the mean number o f eggs

reco rd ed fo r b e e t le s g ive n a d ie t in c lu d in g ca rb o h yd ra te and p ro te in

a t 20 & 25 °C . E c o lo g ic a lly autogeny i s in te re s t in g as i t a llo w s

sp e c ie s to la y v ia b le eggs when a d u lts a re r e s t r ic t e d from f ly in g

outdoors to feed on p o lle n and n e c ta r o f f lo w e rs . T h e re fo re in t o t a l

ly in d o o r environm ents p ro p ag atio n o f th e sp e c ie s i s en su red , a lb e it

a t a s l ig h t ly reduced fe c u n d ity . I t i s p ro b ab le th a t th is re p ro

d u c tiv e s tra te g y i s a m ajo r fa c to r in the su cce ss o f An t h s iz n u * sp e c ie s

as p e s ts in b u ild in g s , p a r t ic u la r ly in urban a re a s where the opp

o r tu n it ie s fo r flo w e r v is it a t io n a re c o n s id e ra b ly r e s t r ic t e d .

F e cu n d ity and a d u lt lo n g e v ity w ere in c re a se d s ig n if ic a n t ly r e la t iv e

to the unfed group in those b e e t le s p ro v id ed w ith a d ie t w h ich in

c lu d ed bo th ca rb o h yd ra te and p ro te in , when fed on e ith e r a lo n e th e re

was no s ig n if ic a n t in c re a s e , e xce p t a t 25°C w here th e p ro v is io n o f

su g ar s o lu t io n in c re a se d lo n g e v ity . Ehgelmann (1 9 7 0 ) co n sid e re d th a t

ca rb o h yd ra te s p e A -de a re n o t d ir e c t ly used in y o lk fo rm a tio n , as

eggs c o n ta in v e ry l i t t l e o f i t , b u t th ey a re p o s s ib ly n e ce ssa ry fo r

u t i l i s a t io n o f d ie t r y p ro te in re s e rv e s . S u r p r is in g ly , the p resen ce

o f w a te r d id n o t have a g re a t e f fe c t upon fe c u n d ity , and indeed

B la k e (1 9 6 1 ) found th a t the p ro v is io n o f w ate r d ecreased fe c u n d ity

*

- 143-

in A .ueA 6a4cX . As k w t h t i e n u . * a re e s s e n t ia lly d ry h a b ita t sp e c ie s by

v ir t u e o f the e c o lo g ic a l n ic h e s th ey e x p lo it , r e lia n c e on fem ales

a c q u ir in g d ie t r y w a te r to m ature eggs would im p a ir t h e ir su cce ss

in such h a b it a t s . F o r the m a jo r ity o f in s e c ts w a te r i s e s s e n t ia l

fo r egg m a tu ra tio n as eggs c o n ta in a co n s id e ra b le amount- 30-80%

(Engelm ann , 1 9 7 0 ). I t i s p ro b ab le th e re fo re th a t s u f f ic ie n t w a te r

i s o b ta in ed from m o b ilis a t io n o f the f a t body re s e rv e s and i t s a s s

o c ia te d re le a s e o f m e ta b o lic w a te r .

O v ip o s it io n was a c y c l ic a l p ro ce ss w ith the m a jo r ity o f eggs be ing

la id in the f i r s t 2-3 weeks o f a d u lt l i f e , d u rin g w h ich tim e a

number o f more o r le s s d is t in c t peaks (u s u a lly 3 o r 4 ) , in the

o v ip o s it io n r a te w ere o b served . Peaks in the r a te o f o v ip o s it io n

w ere co n sid e re d to be a s so c ia te d w ith the c y c l ic a l n a tu re o f egg

m atu ra tio n in t h is sp e c ie s (S e c t io n 1 .3 .1 6 ) . The p e r io d ic it y o f

peaks v a r ie d somewhat te n ta t iv e ly w ith both tem peratu re and d ie t ,

bu t th e re was a g re a t d e a l o f v a r ia t io n between in d iv id u a l fe m a le s ,

and d iffe re n c e s between d ie t s w ere n o t c o n s is te n t a t th e two temp

e ra tu re s te s te d . Coombs & W oodroffe (1 9 8 3 ) d id n o t o b serve any p a t

te rn in the r a te o f o v ip o s it io n o f k .6 a n .r u jL u 6 . T h e ir d e s c r ip t io n

o f egg la y in g su g g ests th a t thene m ight have been had 0-1 day o ld

b e e t le s been used a t the s t a r t o f th e exp erim ent and the number o f

r e p lic a te s in c re a se d to a more re a so n a b le f ig u r e . The e xp e rim e n ta l

tech n iq u es used in the fe c u n d ity s tu d ie s were s ta n d a rd ise d w ith tho se

o f B la k e (1 9 6 1 ) in o rd e r th a t a com parison co u ld be made w ith

k . v & i b a A c J L . C om parative d a ta a re o n ly a v a ila b le a t 20°C where the

o v ip o s it io n r a te s w ere s im ila r . Bo th sp e c ie s s ta r te d o v ip o s it io n

on the 4 th day o f a c t iv e l i f e and 3 (som etim es 4 in k . 6 a ^ y u i c . u 6 )

d is t in c t peaks in th e mean o v ip o s it io n ra te were a p p a re n t. F o r a l l

d ie t s the d u ra tio n o f o v ip o s it in g l i f e was lo n g e r in k . 6 a ^ u v i c . i i 6 .

M ales and fem ales o f k .4 a t in J jL u .6 liv e d lo n g e r than A . ve/iba-dcX on

d ie t s in c lu d in g ca rb o h y d ra te , b u t when t h is was added to the d ie t

th e p o s it io n was re v e rs e d . The o n ly e xce p tio n was k .6 a > u v L c u .6 fem ales

fed on ca rb o h yd ra te and p o lle n w h ich liv e d s ig n if ic a n t ly lo n g e r than

A .ue^6a4cX fem ales on the same d ie t . The mean t o t a l fe c u n d it ie s

w ere h ig h e r fo r k .6 < v iv u x n L6 on a l l d ie t s . The h ig h e s t fe c u n d ity r e

corded fo r k .v Q J ib a .6 c .J L was 6 8 .1 eggs p e r fem ale on a d ie t o f sug ar

s o lu t io n and albumen (B la k e , 1 9 6 1 ), and fo r k .A a . ' i v u .c .u A , 8 2 .7 on a

- 144-

d ie t o f sug ar s o lu t io n and p o lle n .

V irg in fem ales liv e d lo n g e r than mated fem ales on a l l d ie t s a t 20

& 25 °C . Some d id n o t o v ip o s it w h ile o th e rs d id , w ith reduced fe c

u n d ity compared to th e ir mated c o u n te rp a rts . In many in s e c t sp e c ie s

v ir g in s do n o t la y eggs o r la y w ith reduced fe c u n d ity , and m ature

eggs may be re ta in e d in the g e n ita l d u cts o r o v a r ie s o r u lt im a te ly

re so rb ed (Engelm ann , 1 9 7 0 ). V irg in s o f O t iy z a z p Iv L t u * A u tu L n a m w A jU

fo r exam ple , l iv e d 3 tim es lo n g e r than mated fem ales b u t o v ip o s ite d

o n ly o n e - th ird as many egg s. In g e n e ra l, a low ra te o f egg la y in g ,

accom panied by o o so rp tio n , a s so c ia te d w ith a long life - s p a n i s

c h a r a c t e r is t ic o f v ir g in s .

1 .4 .5 In t r in s ic r a te o f p o p u la tio n in c re a s e

The com b ination o f the d a ta on fe c u n d ity , developm ent and m o r ta lit y ,

m o d ified by th e a p p ro p ria te v a lu e s fo r se x r a t io and f e r t i l i t y has

enab led e xp re ss io n s fo r the in t r in s ic r a te o f p o p u la tio n in c re a s e

( r ) , to be e stim a te d and a com parison made w ith A .ue^6a,4cX. _r v a lu e s

w ere c a lc u la te d u s in g the s im p lif ie d method o f Howe (1 9 5 3 ), where

egg p a tte rn i s re p re se n te d by a u n ifo rm ra te o f o v ip o s it io n . The

p aram eter r_ sh o u ld more c o r r e c t ly be d e fin e d as r , the maximum

r a te a t w h ich a p o p u la tio n w ith a s ta b le age d is t r ib u t io n can m u lt

ip ly i f i t has an u n lim ite d food su p p ly . I t i s th e r a te o f growth

th a t a p o p u la tio n o f the sp e c ie s w ould e v e n tu a lly a c h ie v e i f i t

w ere a b le to a vo id a l l e f fe c t s o f overcro w d ing and i s thus an in

d ic a t io n o f th e p o te n t ia l o f th e sp e c ie s (Howe, 1 9 5 3 ).

The optimum tem peratu re range fo r p o p u la tio n in c re a s e o f A . AativuLciiA

i s 20-25°C under th e e xp e rim e n ta l c o n d it io n s used (F ig u re 1 .2 9 ) .

E q u iv a le n t v a lu e s c a lc u la te d from th e d a ta o f Coombs & W oodroffe

(1 9 8 3 ) fo r a 28 day p e rio d a t 65% rh w ere : 0 .1 2 ( la r v a e pu p ating

a f t e r a p p ro x .,1 y e a r ) , 0 .0 8 ( la r v a e p u p atin g a f t e r a p p ro x .,2 y e a rs )

a t 15 °C , 0 .1 6 a t 20°C and 0 .2 0 a t 2 5 °C . A p a rt from 15°C th ese v a lu e s

a re lo w er than t h e ir e q u iv a le n ts o b ta in ed in th e p re se n t s tu d y . The

p r in c ip a l reaso n fo r th is i s the h ig h egg m o rta lity reco rd ed in the

p re v io u s a u th o rs in v e s t ig a t io n . Com parative d a ta fo r k . w i b o i b d L i s

o n ly a v a ila b le a t 20 °C , 70% r h , w here the r v a lu e c a lc u la te d from

- 145-

F ig u re 1 .2 9 In t r in s ic ra te s o f in c re a s e r p e r 28 day p e rio d fo r

k ,6a .tin jLc .u .6 a t d if f e r e n t tem peratu res under co n sta n t

c o n d it io n s . ( I ) in d ic a te s in d iv id u a ls p u p atin g in

1 s t p e r io d , ( I I ) tho se in the 2nd p e rio d a t 15 °C .

- 146-

the d a ta o f B la k e (1 9 5 8 ; 1961) was 0 .3 2 p e r 28 day p e r io d . T h is

su g g ests th a t A.veA6a-6cX has a s ig n if ic a n t re p ro d u c tiv e advantage

o ve r A . 6an .Yu .c.u* under th ese c o n d it io n s . However the r_ v a lu e fo r

th e sm a ll p ro p o rtio n o f r a p id ly d eve lo p in g la rv a e o f A.A a tu v L c u * a t

25 °C , 70% rh was 0 .8 6 p e r 28 day p e r io d . I t i s somewhat a r t i f i c i a l

to c a lc u la te a r a te o f p o p u la tio n in c re a s e based on th e developm ent

o f o n ly a few in d iv id u a ls , b u t i t does g iv e an id e a o f th e p o te n t ia l

o f t h is sp e c ie s under id e a l c o n d it io n s . I t has n o t been determ ined

w hether such ra p id developm ent i s p o s s ib le under f ie ld c o n d it io n s ,

e xp erim en ts in f lu c tu a t in g c o n d it io n s sug gest th a t p e r io d ic changes

in e n v iro n m en ta l c o n d itio n s d ic ta te o th e rw ise .

1 .4 .6 O va rian developm ent

The m ajo r c o n tr ib u t io n o f t h is in v e s t ig a t io n was th a t to a la rg e

e x te n t fem ale age co u ld be determ ined from the c o n d it io n o f the

o v a r ie s . D ata o b ta in ed from d is s e c t io n compared w e ll w ith the r e s u lt s

o f o v ip o s it io n exp erim en ts d e sc rib e d in S e c tio n 1 .3 .1 4 , where u n fe d ,

mated fem ales a t 20 °C , 70% rh s ta r te d o v ip o s it io n on the 5 th day

o f a c t iv e l i f e , and 83% had la id a t le a s t one b a tch o f eggs by the

9 th d a y . T h is ag rees w ith th e d is s e c t io n d a ta , w here the o v a r ie s

had a tta in e d t h e ir maximum s iz e by the 4 th day o f a c t iv e a d u lt l i f e ,

th e c a ly c e s and o v id u c ts b e in g packed w ith eg g s, and by th e 12 th d a y ,

70% o f fem ales had la id a t le a s t one b a tch o f eg g s. A .4a'm Xcu4 ap

peared to o v u la te a number o f eggs o ver a sh o rt p e rio d o f tim e ,fro m

each o v a r io le b e fo re o v ip o s it io n . T h is was a ls o observed by G erb er

(1 9 7 5 ) in T z y ia b n JL o m o Z JU to > i, m ature eggs w ere re ta in e d in the c a ly c e s

and o v id u c ts and fem ales accum ulated com plem ents o f eggs b e fo re the

in i t ia t io n o f o v ip o s it io n . Once the c a ly c e s and o v id u c ts had been

d iste n d e d by eg g s, they rem ained in t h is c o n d it io n , so i t was easy

to d eterm ine i f o v ip o s it io n had o c c u rre d . A f te r the f i r s t b a tch o f

eggs had been o v ip o s ite d , o v a r ie s tended to rem ain in the sta g e 3

c o n d it io n a p a rt from when fu r th e r eggs were o v u la te d , when they

took on the appearance o f a stag e 2 o v a ry .

V irg in fem ales in i t ia t e v it e llo g e n e s is a t the same tim e a f t e r em

ergence as fem ales w ith m a le s . V ite llo g e n e s is i s in it ia t e d b e fo re

c o p u la tio n o c c u rs , s in c e i t was o n ly a f t e r 3 days th a t sperm s t a r t

ed to be found in the sperm athecae o f mated fe m a le s . By the 4 th day

- 147-

90% o f p a ire d fem ales had mated s u c c e s s fu lly and 30% had s ta r te d

o v u la t io n . In c o n t ra s t , v ir g in fem ales rem ained a t the sta g e 1

c o n d it io n a t le a s t u n t i l the 9 th d ay , and even by the 20 th day

o n ly 40% had o vu la te d and o f th ese 20% o v ip o s ite d . These r e s u lt s

a re s im ila r to tho se o b ta in ed by G erber (1 9 7 5 ) fo r T .m o & J t o s i , in

th a t s t im u li a s so c ia te d w ith c o p u la tio n and (o r ) in se m in a tio n a re

n o t re q u ire d fo r the in i t ia t io n o f v it e llo g e n e s is , b u t do a f fe c t

th e o o cyte p ro ce ss la t e r on . Mordue (1 9 6 5 ) found th a t m ating a c c

e le ra te d the r a te o f o o cyte m a tu ra tio n in T .m o V u t o f i and s in c e v ir g in s

r e t a in a lm o st a l l o f the f i r s t m ature o o c y te s , i t i s l i k e ly th a t

egg re te n t io n i s re sp o n s ib le fo r re ta rd in g fu r th e r o o cyte d eve lo p

m ent.

O b se rva tio n s o f m ating b eh av io u r d u rin g th e fe c u n d ity exp erim en ts

(S e c t io n 1 .3 .1 4 ) , in d ic a te d th a t fem ales mate s e v e ra l tim es d u rin g

t h e ir l i f e , b u t i t was n o t determ ined w hether m u lt ip le m atings w ere

re q u ire d fo r fem ales to o v ip o s it t h e ir f u l l complement o f eg g s, o r

w hether the sperm from one in se m in a tio n i s v ia b le and s u f f ic ie n t fo r

th e d u ra tio n o f the o v ip o s it io n p e rio d . M u lt ip le m ating may enhance

fe c u n d ity how ever, s in c e th e re was a d e c lin e in the p ro p o rtio n o f

fem a les w ith sperm a f t e r 21 days when m ales w ere b eg in n in g to d ie .

A fu r th e r in d ic a to r o f age was the e x te n t o f th e f a t body. C o r re l

a t in g t h is w ith the o v a ria n developm ental stag e i t would be p o s s ib le

to d eterm in e i f s tag e 2 fem ales were la y in g th e ir f i r s t o r second

b a tch o f eg g s, as younger fem ales had an e x te n s iv e f a t body, w h ile

o ld e r fem ales a t age 15-18 days had v e ry much le s s f a t . No doubt

d e p le tio n o f f a t body w ould n o t have been so e v id e n t had b e e t le s

been g ive n a cce ss to p ro te in and/o r su g ar and w ate r d u rin g a c t iv e

l i f e . P resum ab ly th e f a t body in v ir g in fem ales d ecreased in s iz e

a t a s lo w e r r a te than mated fem ales because few er o o cytes w ere

b e in g m atured and th e re fo re the req u irem en t fo r m o b ilis a t io n o f

f a t re s e rv e s fo r o o cyte developm ent was le s s .

1 .4 .7 D is s e c t io n o f f ie ld c o lle c te d b e e tle s

The r e s u lt s in d ic a te th a t fem ale A .6cl>iyuLc.u6 do n o t become f l ig h t

a c t iv e u n t i l they have o v ip o s ite d a t le a s t one b a tch o f eg g s, su g g est

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in g th a t i t i s most l i k e ly th a t m ating and o v ip o s it io n o f th e f i r s t

egg b a tch o ccu rs in the p ro x im ity o f w here they em erge. By com parison

w ith the r e s u lt s from d is s e c t io n o f known age b e e t le s (S e c t io n 1 .3 .1 7 ) ,

th e e x te n t o f th e f a t body was in d ic a t iv e o f in d iv id u a ls a t le a s t

9 days in to a c t iv e l i f e . How ever, i t i s p ro b ab ly n o t r e a l i s t i c to

a ttem p t to age b e e t le s w ith in p re c is e l im it s based on th e la b o ra to ry

exp erim en t because o f the lim it a t io n s o f th e e xp e rim e n ta l m ethod.

B e e t le s w ere co n fin e d to g la s s tu b e s , th e reb y r e s t r ic t in g a c t iv i t y

somewhat and p o s s ib ly re d u c in g the req u irem en t fo r m o b ilis a t io n

o f f a t re s e rv e s . The f a t body o f m ales was a ls o red u ced , in d ic a t in g

th a t th ey w ere n o t new ly em erged, a lth o u g h a g e -re la te d changes in

th e m ale f a t body had n o t been s tu d ie d .

The r e s u lt s from th is stu d y a re in agreem ent w ith tho se o b ta in ed

by w o rke rs fo r A .v e jib a .6 (L i,. K u n ike (1 9 3 9 ) s ta te d th a t some o f the

a d u lts found on flo w e rs o r a t windows had a lre a d y co p u la te d and la id

a p ro p o rtio n o f t h e ir eggs b e fo re le a v in g the p la c e in w h ich they

d eve lo p ed . Kuwana (1 9 5 0 ) concluded th a t 80% o f eggs w ere la id b e fo re

fem a les became p h o to p o s it iv e , and 90% o f a d u lts found on flo w e rs

had la id th e ir com plete egg lo a d , w h ile 10% were s t i l l cap ab le o f

o v ip o s it in g . He co n firm ed th is o b se rv a tio n by c o lle c t in g a d u lts

from f lo w e rs , 92% o f w h ich la id no eggs w h ile 8% la id 5-30 eggs

e a ch . B la k e (1 9 5 5 ) concluded th a t i f A .ve /i6 a4 cx mated in th e f i r s t

few days o f a c t iv e l i f e , then fem ales would rem ain a t th e s i t e from

w here th ey emerged u n t i l a f t e r the f i r s t egg b a tch had been la id .

Unmated fem ales how ever, r a p id ly became p h o to p o s itiv e and f le w to

flo w e rs where ag g reg atio n was l i k e ly to r e s u lt in m a tin g . T h is d if f e r s

from th e p re se n t in v e s t ig a t io n in th a t o n ly a sm a ll p ro p o rtio n (< 1% ),

o f fem ale b e e t le s caught outdoors had n o t p re v io u s ly o v ip o s ite d .

T h is su g g ests th a t e ith e r A .^ a tivu Lcu .* a t t a in s a h ig h degree o f m ating

su cce ss b e fo re becoming f l ig h t a c t iv e , w h ich may in tu rn in d ic a te

th a t b e e tle s were em erging from la rg e in fe s t a t io n s w here th e l i k e

lih o o d o f f in d in g a mate was h ig h , an d /o r the age re la te d l ig h t

re sp o n se d if f e r s from th a t o f A .^ e * b a t c l (se e S e c tio n 2 .3 .3 ) .

An im p o rtan t f in d in g was th a t a t le a s t 7% o f m ale and 13% o f fem ale

b e e t le s in 1983 had en te red the Entom ology B u ild in g a f t e r feed in g

o u td o o rs . These f ig u re s a re in f a c t l i k e ly to be u n d e re stim a te s

because o n ly 42% o f m ales and 35% o f fem ales caught on th e outdoor

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tra p s had p o lle n in t h e ir gut c o n te n ts . The fa c t th a t b e e t le s w h ich

had p re v io u s ly been outdoors w ere a tte m p tin g to f l y ou t o f the b u ild

in g a g a in , su g g ests th a t th e re i s a sw itc h in g o f p h o to ta c tic b e h a v io u r,

p o s s ib ly re la te d to egg m a tu ra tio n , a s suggested by B la k e (1 9 5 5 ).

F e c u n d ity in b e e t le s fed on a d ie t o f p o lle n and su g ar s o lu t io n was

in c re a se d 52% compared to unfed b e e t le s (S e c t io n 1 .3 .1 4 ) , th e re fo re

flo w e r v is it a t io n i s l i k e ly to s ig n if ic a n t ly in c re a s e to t a l egg

o u tp u t and a d d it io n a lly i s b e n e f ic ia l in term s o f d is p e r s a l o f g ra v id

fem a les to new h a b ita ts s u ita b le fo r la r v a l developm ent.

None o f the b e e t le s c o lle c te d in the G e n e ra l H erbarium showed s ig n s

o f p r io r fe ed in g on f lo w e rs , p o s s ib ly because windows w ere r a r e ly

opened in t h is p a r t o f the b u ild in g , th e reb y r e s t r ic t in g in te rch a n g e

between in d o o r and outdoor en v iro n m en ts. C le a r ly th e se fin d in g s

h ave im p o rtan t im p lic a t io n s in fo rm u la tin g a s tra te g y fo r c o n tro l

o f k .6 a .f in ic .u 6 and w i l l be d isc u sse d fu r th e r la t e r on in the t h e s is .

«►

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1 .5 Summary

A sp ects o f th e eco logy and b io lo g y o f Aruthn.e.nu6 6an.yuic.u6 w ere s tu d ie d

in the f ie ld and in the la b o ra to ry . The aim s o f t h is p a rt o f the

stu d y were to o b ta in b a s ic in fo rm a tio n on f ie ld a c t i v i t i e s , s ta tu s

and developm ent.

1 . k.6an.Yuic.u6 was reco rd ed in h a b it in g d ry b ird s ' n e s ts in c e n t ra l London

b u t in s u f f ic ie n t n e s t sam ples w ere o b ta in ed to d eterm ine the e x te n t

and im portance o f b ir d s ' n e s ts as a n a tu ra l h a b it a t . I t was co n sid e re d

th a t k.6afinJuc.u6 i s f a i r l y w id esp read in the London a re a d e sp ite the

sm a ll number o f n o t if ie d re c o rd s , p r in c ip a lly because o f t h e ir sm a ll

s iz e and g e n e ra l d i f f i c u l t ie s o f id e n t if ic a t io n o f th e A n th re n in a e .

2 . T rap p in g exp erim en ts a t th e BM(NH) showed th a t a d u lt b e e tle s w ere

found in d o o rs between May and O ctober and outdoors between May and

Septem ber. Peak tra p ca p tu re s w ere a s so c ia te d w ith warm sunny w eather

c o n d it io n s when a d u lts w ere a ls o found feed in g on th e p o lle n and

n e c ta r o f w h ite and y e llo w co lo u re d f lo w e rs .

3 . The l i f e h is to r y o f k.6an.yuicu6 was s tu d ie d in the la b o ra to ry and under

f ie ld c o n d it io n s . Under co n sta n t c o n d itio n s on a d ie t o f f is h m e a l,

y e a s t and c h o le s te ro l developm ent was c ir c a n n u a l, e xce p t a t low

tem p eratu res when p u p atio n was b im odal w ith some in d iv id u a ls ta k in g

1 y e a r to d eve lo p and o th e rs ap p ro x im a te ly 2 y e a r s .

4 . A p e rio d o f d iap au se developm ent ( in d ic a te d by a rre s te d developm ent)

was u s u a lly e v id e n t::in .-m a tu re la r v a e . The d u ra tio n -o f d iap au se was v e ry

v a r ia b le , some la rv a e pupated w ith o u t undergoing an obvious p e rio d o f

d iap au se developm ent w h ile o th e rs rem ained in d iap au se fo r up to 40

w eeks. Developm ent was a ffe c te d by changes in p h o to p e rio d . In c re a s in g

p h o to perio d a t co n sta n t tem peratu re induced la rv a e to pupate w ith o u t

undergo ing an obvious p e rio d o f d iap au se developm ent. A ltho ug h in

cre m e n ta l changes in pho to perio d a f fe c t la r v a l developm ent the r e

sponse may have been due to a c r i t i c a l d ay len g th e xp e rien ced d u rin g

a s e n s it iv e phase t r ig g e r in g non-d iapause developm ent.

5 . Exp erim en ts conducted in a p igeon lo f t have shown th a t s h e lte re d

b ir d s ' n e s ts would be cap ab le o f s u s ta in in g p o p u la tio n s o f k.6an.yuicu6

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in so u th ern En g lan d . The developm enta l c y c le was c lo s e ly syn ch ro n ise d

w ith th e seasons w ith bo th tem peratu re and to some e x te n t changes in

p h o to perio d a f fe c t in g th e developm ental rhythm . The l i f e - c y c le under

outdoor c o n d it io n s may take 1 o r 2 y e a rs to co m p lete .

6 . S u c c e s s fu l la r v a l developm ent o ccu rre d on a w ide range o f d r ie d an im a l

m a te r ia ls . D rie d p la n t m a te r ia ls w ere n o t s u ita b le fo r com plete la r v a l

developm ent.

7 . A d u lts o v ip o s ite d a t tem peratu res from 15 to 3 0 °C , b u t some p a ir in g s

a t a l l tem peratu res w ere in f e r t i l e . The e f fe c t s o f v a r io u s a d u lt

d ie t s on the le n g th o f l i f e , o v ip o s it io n c y c le and fe c u n d ity w ere

in v e s t ig a te d . k,6 a . K Y i L o . \ L 6 i s autogenous and in g e n e ra l fe c u n d ity and

a d u lt lo n g e v ity w ere o n ly in c re a se d s ig n if ic a n t ly r e la t iv e to un fed

b e e t le s when th e a d u lt d ie t in c lu d e d bo th ca rb o h yd ra te and p ro te in .

O v ip o s it io n was c y c l ic a l w ith th e m a jo r ity o f eggs b e in g la id in the

f i r s t 2-3 weeks o f a d u lt l i f e , d u rin g w h ich tim e a number o f more o r

le s s d is t in c t peaks (u s u a lly 3 o r 4 ) in the o v ip o s it io n r a te w ere

o b se rve d . V irg in fem ales liv e d lo n g e r than mated fem ales and some

o v ip o s ite d in f e r t i l e eggs w ith reduced fe c u n d ity compared to t h e ir

mated c o u n te rp a rts .

8 . I n t r in s ic ra te s o f p o p u la tio n in c re a s e w ere determ ined fo r developm ent

a t co n sta n t te m p e ra tu re s . The optimum tem peratu re range fo r dev

elopm ent was 20-25°C .

9 . The anatomy o f the fem ale re p ro d u c tiv e system , p h y s io lo g ic a l sta g e s

o f o v a ria n developm ent and re p ro d u c tiv e b eh av io u r w ere s tu d ie d . An

o v a ria n ra n k in g scheme was d e v ise d and i t was determ ined th a t the

app roxim ate age o f fem ales re a re d in th e la b o ra to ry co u ld be a s c e r ta in

ed from the c o n d itio n o f the o v a r ie s and e x te n t o f the abdom inal f a t

body.

10 . D is s e c t io n o f f ie ld c o lle c te d b e e t le s and exam in atio n o f th e fem ale

re p ro d u c tiv e system s showed th a t fem ale A . 6a.tmjui.UL4 do n o t become f l ig h t

a c t iv e u n t i l they have o v ip o s ite d a t le a s t one b a tch o f egg s. Gut

a n a ly s is showed th a t a t le a s t 7% o f m ale and 13% o f fem ale b e e tle s

trapp ed in th e Entom ology B u ild in g had fed on the p o lle n o f f lo w e rs ,

in d ic a t in g th a t b e e tle s w ere f ly in g in to th e museum from o u ts id e .

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PART I I

BEH A V IO U R S T U D IE S

2 .1 In tro d u c tio n

I t was beyond the scope o f t h is th e s is to u n d ertake w ork on the

b e h av io u r o f A . t a t in X c u .* b u t p re lim in a ry o b se rv a tio n s w ere made o f

a sp e c ts o f b eh av io u r th a t m ight be im p o rta n t, p a r t ic u la r ly in r e l

a t io n to the developm ent o f in fe s t a t io n s and in p la n n in g c o n tro l

s t r a t e g ie s . The a sp e c ts s tu d ie d w ere : se x pheromone re le a s in g behav

io u r , odour d e te c t io n , p h o to ta c t ic resp o n se and h u m id ity d is c r im in

a t io n .

2 .1 .1 Sex pheromone re le a s in g b eh av io u r

A . 6a tiY iLc.u 6 a d u lts had been observed e x h ib it in g a b eh av io u r p a tte rn

th a t has been c o rre la te d w ith the re le a s e o f se x pheromone by fem ale

b e e t le s in A . ^ la v jL p z ,* (B u rk h o ld e r zX a t , 1 9 7 4 ), Atta .g e .v u i6 z X o n g c X u lu .4

Casey (B a ra k & B u rk h o ld e r, 1977) and Jfio g o d zA m a . s p p ., (B u rk h o ld e r

z X a t , , 1 9 6 6 ). R e le a s in g b e h av io u r i s c h a ra c te r is e d by fem ales a s

sum ing a ' h ead stan d ' p o stu re w ith the abdomen e le v a te d from the

s u b s tra te and p a r t ia l exposure o f the o v ip o s ito r segm ents. D ie l

p e r io d ic it y o f c a ll in g b e h av io u r in A. ^ la v X p z .6 has been shown to

o ccu r in a 1 6 :8 LD p h o to perio d (B u rk h o ld e r z X a t , , 1 9 7 4 ). The peak o f

fem ale c a l l in g a c t iv i t y c o in c id e d w ith th e peak in d a ily pheromone

p ro d u c tio n , and was shown to be an endogenous c ir c a d ia n rhythm

e n tra in e d by pho to perio d (Ma z X a t . , 1 9 7 8 ). C irc a d ia n rh y th m ic ity

o f se x pheromone re le a s e h as a ls o been dem onstrated in T>iogodz.n.ma.

g la b ^ iu m (H e rb s t) (Hammack & B u rk h o ld e r, 1 9 7 6 ). B u rk h o ld e r z X a t . ,

(1 9 7 4 ) showed th e a c t iv e pheromone component from A .^ la v X p z .6 to be

an u n sa tu ra te d c a rb o x y lic a c id , w h ich was id e n t if ie d as c i s 3 -d ecan o ic

a c id (F u k u i z X a t , , 1 9 7 4 ). Adams z X a t . , (1 9 7 5 ) found a se x a t t r a c t -

a n t pheromone in A .ve 'i6 a4 cX w h ich they co n sid e re d was a ls o a c a rb

o x y lic a c id . They e va lu a te d the m a le s ’ resp o n se to Cg-C^j s t r a ig h t

c h a in a c id s and found th a t o n ly C ^ (n -u n d ecan o ic ) and p o s s ib ly C^q

( d e ca n o ic ) a c id s w ere a t t r a c t iv e . T*iogodz.n.m a A J ic lu t u m LeC onte have

been shown to produce a complement o f 4 se x pherom ones, 2 o f w h ich

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have been id e n t i f i e d a s ( - ) - 1 4 - m e th y l- c is - 8 - h e x a d e c a n - l- o l and ( - ) -

m e th y l-1 4 -m e th y l-c is-8 -h e x ad e can o a te . C ro ss a t t r a c ta n c y experim en ts

showed th a t some o r a l l o f the 4 compounds, o r c lo s e a n a lo g s th e r e o f ,

a r e in v o lv ed in the se x a t t r a c t a n t s o f o th e r T>iogodQJima. s p e c ie s

(R odin at at, 9 1 9 6 9 ).

The p re se n c e o f se x pheromones i s w id esp read in the D erm estid ae , and

th e u se o f sy n th e t ic pheromones a s p a r t o f a p e s t management s t r a t e g y

a g a in s t th e se in s e c t s h a s been su g g e s te d (V ick at at., 1973; Burkholder

at at., 1 9 7 4 ). I t was im p ortan t th e re fo re to determ ine i f such a

pheromone was to be found in A. 6a intcu6. Experim ents were aim ed a t

in v e s t ig a t in g the r e la t io n s h ip between the t y p ic a l h ead stan d p o s tu re

and pheromone r e l e a s e , d a i ly rh y th m ic ity o f c a l l i n g b e h a v io u r , and

d eterm in in g the age o f fem ale s a t which c a l l i n g began .

2 .1 .2 O lfa c t io n experim en ts

O L factio n i s a l s o im p ortan t in a s s i s t i n g many in s e c t s to f in d fo o d ,

o v ip o s i t io n s i t e s and to a v o id u n fav o u rab le environm ents. F or exam ple

Imamura (1935) found th a t though sc e n t p lay e d no p a r t in a t t r a c t i n g

A.vanboLtci, a d u l t s to f lo w e r s , i t was im p ortan t in e n ab lin g la r v a e to

f in d fo o d . B lak e (1955) on th e o th e r hand, found th a t a d u l t s were

a t t r a c t e d by flow er sc e n t and by the odour o f o v ip o s i t io n s u b s t r a t e s

such a s b i r d s ' n e s t m a t e r ia l , b u t th e se re sp o n se s were dependant

upon the p h y s io lo g ic a l c o n d it io n o f the i n s e c t s . L arv ae were a t t r a c t

ed to b i r d s ' n e s t odour, which was c o n sid e re d by B lak e (1955) to

en su re th a t la r v a e em erging from eggs in a n e s t would rem ain th e re ,

and th o se em erging in the v i c i n i t y o f a n e s t to be s t r o n g ly a t t r a c t e d

to i t . I t was o f i n t e r e s t th e r e fo r e to determ ine i f the odours o f

d r ie d an im al, and p o s s ib ly p la n t m a te r ia ls were a t t r a c t i v e to A.4a^nXca4

a d u l t s and la r v a e , th ereby p ro v id in g fu r th e r in fo rm atio n on the

mechanisms o f in f e s t a t io n by t h i s in s e c t . There h as been much con

tr o v e r sy too over the e f f e c t iv e n e s s o f n aph th alen e and p a ra d ic h lo ro -

benzene (PD B), a s p r o te c ta n t s fo r househ old w oollen p ro d u c ts and

museum specim ens a g a in s t a t t a c k by c lo th e s moths and c a r p e t b e e t le s

(H e r r ic k , 1934; A bb ott, 1 9 3 5 ), th e re fo re sim p le o lfa c to m e te r e x p e r

im ents were conducted to determ in e t h e ir r e p e l le n t p r o p e r t ie s to

A. 6a.n.YiJL(UL6.

*

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2 .1 .3 P h o to ta c t ic re sp o n se o f a d u l t b e e t le s

In A.vejiba6cJL, B lak e .(1955) determ ined th a t the o n se t o f p h o to p o s it

iv e b e h av io u r , and hence f l i g h t a c t i v i t y , was r e l a t e d to m ating

c o n d it io n . V irg in fem ales became p h o to p o s it iv e a t an e a r l i e r age than

m ated fe m a le s , w ith the l a t t e r r e v e r t in g to p h o to n e g a tiv e beh av iou r

d u rin g p e r io d s o f o v u la t io n . I t ap peared th a t a s im i la r phenomenon

was o c c u rr in g in A.6a>uvLcu.4. The d i s s e c t io n s d e sc r ib e d in S e c t io n 1 .3 .1 7

showed th a t a d u l t b e e t le s c o l l e c t e d a t windows were s e v e r a l day s o ld

and th e fem ales had o v ip o s i te d a t l e a s t one egg b a tch p r io r to b e in g

c a u g h t. To determ ine i f th e re sp o n se to l i g h t was dependant upon

ag e an d /o r m ating c o n d it io n , th e r e a c t io n s to l i g h t o f m ated m a le s ,

and m ated and v i r g in fem ales were in v e s t ig a t e d a s they ag ed , u s in g

l ig h t - d a r k ch o ic e cham bers.

2 .1 .4 L a r v a l hum idity d is c r im in a t io n

The m a jo r ity o f d erm estid b e e t le s a r e d r y - h a b ita t s p e c ie s and hum

i d i t y i s c o n sid e re d to be im p ortan t in the s e le c t io n o f s u i t a b le

o v ip o s i t io n and l a r v a l developm ent s i t e s . For exam p le ,Tkogodz ima gfianoLfiLum E v e r t s , p r e fe r r e d dry m alt in s to r a g e and tended to a v o id

m o ist p a tc h e s (B u rg e s , 1 9 5 9 ), and la r v a e and a d u l t s o f A.v<L>ibcL6cJL p r e fe r r e d the low er o f any p a i r o f h u m id it ie s o f f e r e d , which B lak e

(1970) c o n sid e re d to be ad van tageou s in th a t b i r d s ' n e s t s b u i l t in

exposed s i t u a t io n s r a r e ly su rv iv e lon g enough to su p p o rt th e 1-3

year- l a r v a l developm ent p e r io d o f t h i s in s e c t . As A.4a-micu-6 i s

c a p a b le o f com pletin g developm ent over a wide ran ge o f h u m id it ie s

(S e c t io n 1 . 3 .6 ) , i t i s u n l ik e ly th a t environm ental m o d ific a t io n o f

hum idity cou ld be employed to c o n tr o l t h i s in s e c t in museums.

However i t was o f i n t e r e s t to determ ine th e hum idity p re fe re n c e o f

l a r v a e , p a r t i c u l a r ly a s an in f e s t a t io n o f an u n id e n t i f ie d AnthtiejwA s p e c ie s had been found in m o ist p igeo n guano a t the BM(NH). I f in

f a c t A .ôaioLcu.* p r e fe r r e d a d i f f e r e n t hum idity ran ge fo r d e v e lo p

ment compared to th e n a t iv e AnthKzna6s p e c ie s , then t h i s may have

im p ortan t im p lic a t io n s in term s o f n ich e s e p a r a t io n , and would g i^ e

fu r th e r c lu e s a s to the k in d s o f h a b i t a t s which a re l i k e l y to be

su p p o rt in g w ild p o p u la t io n s o f A. AasivuLcuA.

2 .2 M a te r ia ls and Methods

2 .2 .1 Sex pheromone r e le a s in g beh av iou r

The b e e t le s u sed were from a c u lt u r e m ain tain ed a t 25 + 1 °C , 40-50%

r h , in a 16:8LD p h o to p erio d . A l l experim en ts were conducted in th e se

c o n d it io n s u n le s s s t a t e d o th e rw ise . Pupae were sexed and m ales and

fem ale s k ept s e p a r a te ly . Upon em ergence from the l a s t l a r v a l sk in they

w ere termed 0 d ays o ld , and fem ales were p la c e d s in g ly in 50 x 25mm

g l a s s tu bes w ith a 25 x 20mm p ie c e o f p le a te d f i l t e r p ap er a s a

c ra w lin g s u r f a c e .

In a p re lim in a ry experim ent the a s s o c ia t io n o f h ead stan d beh av iou r

w ith the r e l e a s e o f pheromone was in v e s t ig a t e d u s in g the d i s k b io

a s s a y tech n iqu e o f Burkholder oX al.,(1 9 7 4 ). 6mm d iam eter f i l t e r

p ap e r d i s k s (Whatman N o . l ) , p ie rc e d onto s t a i n l e s s s t e e l entom ol

o g ic a l p in s were h e ld 4-5mm above a s t a t io n a r y fem ale fo r 15 m ins.

I f th e b e e t le was d is tu r b e d a t a l l d u r in g the in tro d u c tio n o f the

d i s k , then the d i s k was removed and th e b e e t le l e f t to s e t t l e down

fo r %hr b e fo re the n ex t re c o rd in g in t e r v a l . The le n g th o f p in re q

u ir e d fo r the d i s k to be the a p p r o p r ia te h e ig h t above the b e e t le was

p re ju d g e d and th e le n g th a d ju s te d a c c o rd in g ly beyond th e su p p o rtin g

c o rk (25 x 25mm), which r e s t e d on th e top o f the tube d u rin g d i s k

ex p o su re (F ig u re 2 .1 ) . The co rk s u r fa c e was covered w ith aluminium

f o i l which was re p la c e d fo r each t e s t , red u c in g the l ik e l ih o o d o f

pheromone p erm eatin g the co rk s u r fa c e and con tam in atin g l a t e r a s s a y s .

A n o te was made o f fem ales th a t had e x h ib ite d th e c a l l i n g p o s tu re

d u rin g a 15 min ex p o su re to the d i s k s , a f t e r which th e d i s k s were

prom ptly b io a s sa y e d w ith 5 m ales h e ld in a s t a i n l e s s s t e e l c i r c u l a r

a re n a (54mm d ia m .) , r e s t in g on f i l t e r p ap e r (Whatman N o . l ) . The

d i s k exposed to th e fem ale was p la c e d in one h a l f o f th e are n a and

a c le a n c o n tr o l d i s k p la c e d in the o th e r . The number o f m ales ex

h ib i t in g e x c i t a b le b eh av iou r tow ards th e d i s k s w ith in 60 secon ds

was re co rd e d . 20 v i r g in fe m a le s , 4-8 days o ld a t the s t a r t o f the

experim ent were a s sa y e d w ith 3-7 day o ld m ale s , 5 to each o f 20

a r e n a s . D isk s were in tro d u ced to the fem ales 6hrs in to th e photo

p h ase (1 2 .0 0 h r s GMT), and the experim ent re p e a te d on 3 c o n se c u tiv e

d ay s u s in g the same in d iv id u a l s . A c o n tr o l experim ent was c a r r ie d

o u t where a s im i la r number o f d i s k s were exposed to m ales (5 -9 day

o l d ) , in s te a d o f fe m a le s , and the d i s k s a ssa y e d w ith grou ps o f 5

m ales (6 -1 0 day o ld ) .

- 156-

«F ig u re 2 .1 Diagram o f d i s k b io a s s a y tech n iqu e to c o l l e c t se x

pheromone from fem ale k.6a.n.nJjn±& (n o t to s c a l e ) .

*

- 157-

The ex p e rim e n ta l p rocedu re d e sc r ib e d above was adopted to o b se rv e

i f th e re was d a i ly p e r io d ic i t y in c a l l i n g b e h av io u r . D isk s were in t r o

duced to fem ales a t %hr in t e r v a l s from lh r b e fo re the s t a r t o f the

p hotoph ase (5 .0 0 h r s GMT), u n t i l the b eg in n in g o f the sc o to p h ase

(2 2 .0 0 h r s GMT). A c t iv it y d u rin g the sco to p h ase was ob serv ed by th e

l i g h t from a re d darkroom s a f e l i g h t (Kodak W ratten s a f e l i g h t f i l t e r

N o .2 ) . A lthough no t e s t s had been u ndertaken , i t was assum ed th a t re d

w avelen gth s were o u t s id e th e v i s i b l e spectrum o f A. 4a.sivu.cu6, a s

shown by D e th ie r (1963) f o r o th e r in s e c t s p e c ie s . As in the p re v io u s

experim ent fem ale p o s tu re was n oted and the d i s k s b io a s sa y e d w ith

grou ps o f 5 m a le s . 20 v ir g in fem ales 6-7 days o ld were a s sa y e d w ith

100 m ales (3 -1 0 day o ld ) , a s b e fo r e , and the experim ent re p e a te d over

4 c o n se c u tiv e days u s in g the same i n s e c t s .

To determ ine the age a t which c a l l i n g b e g a n ,25 v ir g in fem ales were

k e p t in d iv id u a l ly and ob serv ed on 5 c o n se c u tiv e days from the s t a r t

o f a c t iv e l i f e ( i . e . 0-1 days o ld a t the s t a r t o f the ex p e rim e n t). The

number o f fem ales e x h ib it in g c a l l i n g b eh av iou r S^h rs in to the p h o to

p h ase was n o ted , b u t the m ale b io a s s a y was n ot u sed a s i t had p r e

v io u s ly been shown th a t th e h ead stan d ( c a l l i n g ) p o s tu r e was a s s o c

i a t e d w ith pheromone r e l e a s e .


The o lfa c to m e te r u sed was b a se d on the d e s ig n o f S p an g le r (1 9 6 5 ) . The

a p p a ra tu s c o n s i s t e d o f a sm a ll a re n a w ith a w ire mesh bottom r e s t i n g

on two fu n n e ls se rv in g a s in f lu e n t p o r t s d i r e c t in g two a ir s t r e a m s

through the mesh (F ig u re 2 .2 ) . The a ren a c o n s is t e d o f a p ie c e o f

p e rsp e x 10 x 7 x 0.5cm w ith a 7 x 4cm h o le c u t in th e c e n tr e . A 30

mesh b r a s s sc re e n f lo o r was s tu c k to the u n d e rsid e o f the p e r sp e x ,

c o v e r in g the h o le , and an a re n a 5cm h ig h made o f p l i a b l e p l a s t i c

cov ered w ith b la c k p ap er on the o u t s id e and c o a te d w ith Fluon on

th e in s id e to p rev en t e sca p e o f th e t e s t i n s e c t s , was f i t t e d in to the

h o le , b u t t in g up a g a in s t the sc re e n f l o o r . U sing f l e x i b l e p l a s t i c to

e n c lo se the r e c ta n g u la r a re n a gav e th e a re n a sm oothly rounded

c o m e r s , thereby e lim in a t in g ’ d e a d -sp a ce s * in which the t e s t in s e c t s

c o u ld a g g r e g a te . The twin fu n n el arrangem ent was made by c u t t in g

h y p e rb o lic s e c t io n s from two 3.5cm p o ly e th y le n e fu n n e ls , which were

*

- 158-

F ig u re 2 ,2 Diagram o f m o d ified v e n tu r i- ty p e o lfa c to m e te r a p p a ra tu s(n o t to s c a l e )

Sat. salt solns. Dividing baffle

F ig u re 2 .3 A lte r n a t iv e chamber u sed in t e s t s o f h um idity d is c r im in a t io n

- 159-

then cemented to g e th e r w ith a th in p ie c e o f p l a s t i c between the c u t

s u r f a c e s . Two h o r iz o n ta l b a f f l e s o f 30-mesh sc re e n were p la c e d in

each o f the fu n n e ls to more even ly d i s p e r s e the a i r p a s s in g through

them. The fu n n e ls were f ix e d ben eath the aren a w ith th e c e n t r a l

p a r t i t i o n b i s e c t in g the bottom o f the aren a in to two e q u a l h a lv e s .

The aren a was le v e l l e d u sin g a sm a ll s p i r i t - l e v e l .

The a i r su p p ly was p ro v id ed from a s ta n d a rd B r i t i s h Oxygen Company

a i r c y l in d e r , and was co n d itio n e d to ap p rox im ate ly 70% rh by bub

b l in g through a 21 f l a s k c o n ta in in g s a tu r a te d sodium c h lo r id e s o l

u t io n . A ir flow was re co rd e d and a d ju s te d w ith 'R o tam eter' flow

m e te r s , and fo r a l l t e s t s a i r a t a r a t e o f 200cm3/m in was p a sse d

through each s id e o f the a re n a . The 'o d ou ro u s ' m a t e r ia l s were t e s t

ed by p la c in g a sm a ll amount between wads o f g l a s s wool in g l a s s

tu b e s 8 x 2cm d ia m ., in s e r i e s w ith one o f the a i r l i n e s . The g l a s s

w ool pads reduced the l ik e l ih o o d o f p a r t i c l e s b e in g c a r r ie d in the

a i r stream to the in f lu e n t fu n n e l. The second a i r - l i n e was f i t t e d

w ith a 'c o n t r o l ' tube c o n ta in in g only g l a s s w ool. A l l experim en ts

w ere conducted a t 25°C in the l i g h t , and a l l in s e c t m a te r ia l was

from c u lt u r e s re a re d in th e same c o n d it io n s (25 + 1 °C , 40-50% rh ,

16:8LD p h o to p e r io d ) . The o l f a c t o r y r e a c t io n s were re co rd e d o f

e a r ly and l a t e s t a g e la r v a e s t a r v e d fo r 2 days p r io r to t e s t in g

when exposed to odour from th e fo llo w in g su b s ta n c e s :

1 . Food m a t e r ia l s :

F ish m eal

C rushed, d r ie d Ttnz.bn.jLo motiton. b e e t le s *

D ried y e a s t

Sp arrow s' n e s t m a te r ia l *

Bran f l a k e s

Old herbarium specim ens

2 . R e p e l le n ts :

N aphthalene *

P arad ich lo rob en zen e (PDB) *

In a d d it io n , the r e a c t io n s o f v i r g in (0 -2 day o ld ) and mated (3 -7

day o ld ) , fem ale a d u l t s were t e s t e d to th o se su b s ta n c e s marked w ith

an a s t e r i s k ( * ) , ex ce p t f o r th e two r e p e l l e n t s , where on ly mated

a d u l t s were t e s t e d .

- 160-

The two r e p e l le n t ch em ica ls were a p p lie d in ace to n e so lu t io n to

5 x 1.5cm f i l t e r p ap er s t r i p s to g iv e d e p o s i t s o f 500mg a c t iv e in

g r e d ie n t . A fte r ev ap o ra tio n o f th e so lv e n t the im pregnated p a p e rs

were p la c e d in the odour cham bers, a lo n g w ith a sm a ll q u a n tity o f

c ru sh ed Ttne.btuLo b e e t le s so a s to p ro v id e a so u rce o f a t t r a c ta n c y

a g a in s t which the r e p e lla n c y c o u ld be t e s t e d (B u sv in e , 1 9 7 1 ). For

th e c o n tr o l t e s t s c le a n a i r was p a s se d through each s id e o f the

o lfa c to m e te r .

20 in s e c t s were u sed fo r each t e s t , they were p la c e d in th e m idd le

o f the aren a a t the s t a r t o f the experim ent and t h e ir p o s i t io n s

re co rd e d every 5 mins fo r a 2hr p e r io d . A fte r each t e s t a l l the

a p p a ra tu s d i s t a l to the odour cham bers was d ism an tled and c le an e d

w ith a b s o lu te a lc o h o l . The odour and c o n tr o l stream s were then

changed over to red u ce any p o s s i b i l i t y o f b i a s in th e a p p a r a tu s , and

th e t e s t r e p e a te d . 4 r e p l i c a t e s were c a r r ie d o u t fo r each su b sta n c e

and each developm en tal s t a g e . D if fe r e n t b a tch e s o f in s e c t s were u sed

f o r s u c c e s s iv e t e s t s on th e same day to e lim in a te any c o n d it io n in g

e f f e c t s o f the o d o u rs.

X 2 v a lu e s were c a lc u la t e d fo r each r e p l i c a t e and tran sform ed to th e

con tin gen cy c o e f f i c i e n t C, w here:

which g iv e s a ro b u st m easure o f the e x te n t o f a s s o c ia t io n between

tre a tm e n ts ( S i e g e l , 19 5 9 ).

2 .2 .3 P h o to ta c t ic re sp o n se o f a d u l t b e e t le s

L ig h t-d a r k a l t e r n a t iv e cham bers were c o n stru c te d from 14cm p l a s t i c

p e t r i d ish e s 1.7cm d eep , h a l f o f which was p a in te d b la c k . B e e t le s

w ere in tro d u ce d onto p ie c e s o f cream co lo u re d p u re w oollen b la n k e t

m a t e r ia l (18 x 18cm ), and the p e t r i d is h chamber im m ediately in

v e r te d over them and f ix e d se c u r e ly to the c lo th w ith ce llo p h an e

ta p e (3M L t d . , S e l l o t a p e ) . Each experim ent was r e p l ic a t e d 4 tim es

and th e cham bers p la c e d on a l e v e l bench p o s it io n e d in d i f f e r e n t

h o r iz o n ta l o r ie n ta t io n s to e lim in a te p o s s ib le com pass o r o th er d i r

e c t io n a l e f f e c t s . The cham bers were u n d istu rb ed fo r the d u ra tio n o f

- 161-

th e ex p e rim e n ts. A l l experim en ts were conducted a t 20 + 1 °C , 65 + 5%

r h , 16:8LD p h o to p e rio d . F lu o re sc e n t s t r i p l ig h t in g in the c e i l i n g

p ro v id e d d i f f u s e i l lu m in a t io n above th e d i s h e s .

F o r the f i r s t experim ent grou ps o f 10 m ale and 10 fem ale 0 -1 day o ld

b e e t l e s were u se d , m ales were marked by ru bbin g o f f a sm a ll p a tch o f

s c a l e s from th e r i g h t e ly t r o n . For the second experim ent grou ps o f

unmated 0-1 day o ld fem ales were u sed . The number o f m ale an d /o r

fem ale b e e t le s on the i l lu m in a te d s id e were re co rd e d every 15 mins

f o r two 2hr p e r io d s d u rin g the photoph ase (5 -7 and 9 - l lh r s from the

s t a r t o f l i g h t s on a t 6 .0 0 h r s GMT). R ecords were taken every 1-2 days

f o r the f i r s t 20 days o f a c t iv e a d u lt l i f e .

2 .2 .4 L a r v a l h um idity d is c r im in a t io n

The a p p a ra tu s u sed was o f th e choice-cham ber type (F ig u re 2 .3 ) , and

was e s s e n t i a l l y a 14cm p l a s t i c p e t r i d ish 1.7cm d eep , d iv id e d in to

two e q u a l h a lv e s by a v e r t i c a l s t r i p o f p l a s t i c 7mm h ig h , f ix e d in

p o s i t io n w ith p a r a f f in wax. A ta u t a ren a o f m uslin c lo t h was g lu e d

onto a c i r c u l a r p l a s t i c fram e 13cm in d iam eter which r e s t e d a c r o s s

th e d iv id in g b a f f l e and was p rev en ted from ro ck in g by su p p o rts f i t

te d to the p e r im e te r o f th e d i s h . The t e s t in s e c t s craw led on the

m u slin a re n a and were p rev en ted from e sc a p in g by an in v e r te d N o .11

d i s h l i d , 10.5cm d ia m ., and 5mm h ig h , the c e n tr e o f which had been

d r i l l e d o u t to p ro v id e an e n try p o r t f o r in tro d u c in g the i n s e c t s .

The in v e r te d d ish l i d a llow ed th e l i d o f the choice-cham ber to be

removed w ith ou t d is tu r b in g the hum idity g r a d ie n t e x c e s s iv e ly . The

r e q u ir e d h u m id it ie s were produced by a p p r o p r ia te s a t u r a te d s a l t

s o lu t io n s ( s e e S e c t io n 1 . 2 .6 ) , p la c e d in the b a s e o f th e chamber

( a p a r t from 50% rh where s u i t a b le s a l t s were n o t a v a i l a b le and K0H

s o lu t io n o f a p p r o p r ia te s p e c i f i c g r a v i t y was u s e d ) . The hum idity

g r a d ie n t was t e s t e d d u rin g p re lim in a ry ru n s by p la c in g c o b a l t th io

c y a n a te p ap er s t r i p s a c r o s s th e a re n a , th e c o lo u r o f th e se p a p e rs

w ere checked a g a in s t s ta n d a rd s k ep t over KOH s o lu t io n s o f known

h um id ity (S e c t io n 1 .2 .6 ) . The hum idity g r a d ie n t ex tended fo r a max

imum o f 1cm between the two h a lv e s o f the aren a and rem ained s t a b l e

f o r a t l e a s t 8 h o u rs .

«

- 162-

The a re n a s were p la c e d on a l e v e l t a b le and e n c lo se d by a b la c k

c i r c u l a r surround 35cm h ig h , i l lu m in a t io n was d i f f u s e from f lu o r

e sc e n t s t r i p l i g h t s in the c e i l i n g . The t e s t in s e c t s were 5 th -6 th

i n s t a r la r v a e from c u l t u r e s k ep t a t 25 + 1 °C , 16:8LD p h o to p e rio d , and

a l l experim en ts were conducted in th e se c o n d it io n s . L arv ae were

p re c o n d it io n e d to e i t h e r 30 o r 70% rh fo r a t l e a s t 2 weeks b e fo r e

b e in g u sed fo r the ex p e rim e n ts. Four h u m id it ie s o f 30 , 50 , 70 &

90% rh were u sed and th e se were combined to g iv e 6 d i f f e r e n t g ra d

i e n t s , 3 0 /5 0 , 3 0 /7 0 , 3 0 /9 0 , 5 0 /7 0 , 50 /90 and 7 0 /9 0 . E ig h t r e p l i c a t e s

were c a r r ie d ou t f o r each com parison , and the cham bers were arran g ed

in d i f f e r e n t h o r iz o n ta l o r ie n ta t io n s to e l im in a te p o s s ib le e x te r n a l

b i a s . F or each t e s t 20 la r v a e were in tro d u ced in to the c e n tr e o f the

a re n a and the numbers on each s id e o f th e chamber re co rd e d every 5

m inutes fo r 2 h o u rs .

- 163-

2 .3 R e s u l t s

2 .3 .1 Sex pheromone r e le a s in g b eh av io u r

C a l l in g fem ales were u s u a l ly found n ear the top o f the p le a te d f i l t e r

p ap e r and when n ot c a l l i n g they tended to be n ear the bottom o f the

v i a l o r c raw lin g over the p ap er s u r f a c e . The c a l l i n g p o s tu r e was

i d e n t i c a l to th a t reco rd ed by Burkholder at at., (1974) f o r A.filavjLpz* (F ig u r e 2 .4 ) .

89% o f m ales o r ie n te d to d i s k s exposed to fem ales e x h ib it in g the

h e ad stan d p o s tu r e , only 15% o r ie n te d to th o se exposed to fem ale s in

th e norm al s t a n c e . In both in s ta n c e s th e re sp o n se to c o n tr o l d i s k s

was low (T a b le 2 .1 ) . M ales d id n ot show any re sp o n se to d i s k s ex

p o sed to m ales o r to the c o n t r o l s . The m ale re sp o n se was c h a r a c te r

i s e d by in c r e a se d e x c i t a b i l i t y w ith an in c r e a se d r a t e o f tu rn in g

upon en cou n terin g a d i s k , r a p id movements o f the an ten n ae , e x te n s io n

o f the g e n i t a l i a , and a tte m p ts to c o p u la te w ith the f i l t e r p ap er

and o th e r m a le s . The r e s u l t s in d ic a te th a t the c a l l i n g p o s tu r e i s

a s s o c ia t e d w ith se x pheromone r e l e a s e . The f a c t th a t 15% o f m ales

resp on ded to fem ales n o t in t h i s p o s tu r e , may be a t t r ib u t a b le to

fem ale s which had been c a l l i n g p r io r to the o b se r v a t io n s , when p hero

mone would have accum ulated in th e v i a l and perm eated th e f i l t e r

p ap e r c raw lin g s u r f a c e .

F ig u r e 2 .4 C a l l in g p o s tu re o f fem ale A.asiruLcu.*.

The d a i ly p e r io d ic i t y o f c a l l i n g a c t i v i t y was s im i la r over the 4

d ay s th a t o b se rv a t io n s were made and a d iu r n a l rhythm o f c a l l i n g

b eh av io u r was ap p aren t (F ig u r e 2 .5 ) . C a l l in g began 2^hrs in to the

ph otop h ase (8 .0 0 h r s GMT), peaked a t 8\ h r s (1 4 .3 0 h r s GMT), and

- 164-

P o stu re

FEMALES IN VIAL Male response to d isk exposed to female (%)

sMale response to

co ntro l d is k (%)

MALES IN VIALS

Male response to d isk exposed to * male {%)

Male response to

co n tro l d is k (%)

NORMAL 1 5 .1 1 .1 0 0

HEAD-STAND

8 8 .7 0 .9 - -

T a b le 2 .1 T o ta l p e rc e n ta g e s o f m ales re sp on d in g to a s s a y d i s k s

c e a se d a f t e r 12% h r s (1 8 .3 0 h rs GMT). The mean number o f fem ales

c a l l i n g a t the p eak p e r io d was 71%. M ale re sp o n se to d i s k s exposed

to fem ale s fo llo w ed the same tren d a s fem ale c a l l i n g b eh av io u r

(F ig u r e 2 .5 b ) , the mean maximum re sp o n se was 64% a t 8-8% h r s in to

th e photophase and no fu r th e r re sp o n se was ob served a f t e r 13 h rs

(1 9 .0 0 h r s GMT). The f a c t th a t m ales responded up to 1 h r a f t e r

fem ale c a l l i n g had c e a se d was a t t r ib u t e d to pheromone m olecu les

d i f f u s i n g from the f i l t e r p ap er c ra w lin g s u r fa c e .

C a l l in g beh av iou r s t a r t e d when fem ales were 1-2 days o ld and q u ic k ly

re ach e d a maximum a t 3-4 days (T ab le 2 .2 ) .

Age (d a y s ) 0-1 1-2 2-3 3-4 4-5

Number c a l l i n g 0 2 8 20 18

% c a l l i n g 0 8 .0 3 2 .0 8 0 .0 7 2 .0

T a b le 2 .2 Change in re sp o n se o f number o f fem ales c a l l i n g a t p e r io d s

a f t e r em ergence from the l a s t l a r v a l sk in

F ig u re 2 .5 D a ily p e r io d ic i t y o f fem ale c a l l i n g b eh av io u r ( a ) and m ale

re sp o n se to d i s k s exposed to fem ales ( b ) . V e r t ic a l l in e s

in d ic a te s tan d ard e r r o r s .


The r e s u l t s a r e i l l u s t r a t e d in F ig u re 2 .6 . When th e re i s a com plete

l a c k o f any a s s o c ia t io n C e q u a ls z e ro , w h ile the upper l im i t i s a

fu n c tio n o f th e number o f c a t e g o r ie s , in th i s c a s e Jh = 0 .7 0 7 . 1 and

5% x 2 p r o b a b i l i t y v a lu e s below which th e re i s no s i g n i f i c a n t a t t

r a c t io n o r re p e lle n c y a r e in d ic a te d . Young la r v a e were a t t r a c t e d to

odou rs d e r iv e d from d r ie d an im al p ro d u c ts , b u t were in d i f f e r e n t to

th e odours o f p la n t d e r iv a t iv e s ( in c lu d in g y e a s t ) . None o f the su b

s t a n c e s t e s t e d were h ig h ly a t t r a c t i v e to l a t e i n s t a r la r v a e ; only

th e odours o f f ish m e a l, cru sh ed b e e t le s and m a r g in a l ly , y e a s t powder,

showed any s i g n i f i c a n t a t t r a c t i o n . R espon ses o f mated and v ir g in

fem ale a d u l t s were s im i l a r , bo th b e in g in d i f f e r e n t to the odours o f

d r ie d b e e t le s and b i r d s ’ n e s t m a t e r ia l . N apthalene and PDB were

s t r o n g ly r e p e l le n t to a l l s t a g e s t e s t e d , w ith PDB ten d in g to be more

so than n ap th a le n e .

2 .3 .3 P h o to ta c t ic re sp o n se o f a d u lt b e e t le s

The number o f co u n ts o f b e e t le s on the il lu m in a te d s id e were c a l c

u la te d fo r each r e p l i c a t e and e x p re sse d a s a p ro p o r t io n o f the t o t a l

in each r e p l i c a t e . A fte r about 16 days a sm a ll number o f the mated

b e e t l e s s t a r t e d to d i e ; the p h o to p o s it iv e p ro p o r t io n s were c o r re c te d

f o r t h i s . A mean re sp o n se fo r th e 4 r e p l i c a t e s was c a lc u la t e d and

th e se r e s u l t s a r e e x p re sse d g r a p h ic a l ly in F ig u re 2 .7 . A h igh p ro

p o r t io n o f bo th mated and unmated fem ales were p h o to n g a tiv e fo r theA

f i r s t 8 days o f a c t iv e a d u l t l i f e ( i . e . p ro p o rtio n p h o to p o s it iv e

> 0 . 5 ) , and when 8-10 days o ld r a p id ly became more p h o to p o s it iv e ,

w ith unmated fem ales becoming so s l i g h t l y slo w e r . The peak re sp o n se

to l i g h t fo r bo th grou ps o f fem ales was between d ay s 16-20 , w ith

v i r g in fem ales e x h ib it in g a s t ro n g e r re sp o n se .

The r e a c t io n o f mated m ales was more v a r i a b le , a s in d ic a te d by the

c o n fid e n ce i n t e r v a l s . They were l e s s p h o to n eg a tiv e than fem ales from

th e o u t s e t o f a c t iv e a d u lt l i f e , b u t the r a t e o f change o f re sp o n se

was slo w er and a f t e r 10 days a sm a lle r p ro p o rtio n were p h o to p o s it iv e

than fe m a le s . Many egg s were l a i d d u rin g t h i s experim ent b u t i t was

n o t n o t ic e d u n t i l th e a p p a ra tu s was d ism an tled when i t was found th a t

CO

NT

ING

EN

CY

C

OE

FF

IC

IE

NT

S

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O D O U R S O U R C E

o x 030 -< zco 03 COX z X o 030 zco z Xo — mx m mo X ■on > o o m x m x > oz CO m— > co> > mx X 03 z m— co> X □3'-1 X -m CO —CO Z 003 X —1 -im - IX XX 2 r~o -I X - > -1 X i~o X -1O m m o m S O X o m o XI- > CO x; r~ m— > (- to a: >

r~ > z c 1“ (—cos m m

m z zCO m m

M a te d f e m a l e s

#

§:8:8?

F ig u r e 2 .6 Contingency c o e f f i c i e n t s o f a t t r a c ta n c y o r r e p e lle n c y o f

A.4a^wXca4 to d i f f e r e n t odour so u r c e s . V alues ex ceed in g

p = 0 .0 5 in d ic a te a s i g n i f i c a n t re sp o n se . E rro r b a r s r e p

r e s e n t 95% co n fid en ce i n t e r v a l s .

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F ig u re 2 .7 P h o to ta c t ic re sp o n se o f a d u l t b e e t l e s .

E f f e c t s o f a g e , se x and m ating c o n d it io n on

the re sp o n se to l i g h t .

( a ) mated m ales

(b ) mated fem ales

(c ) v i r g in fem ales

E rro r b a r s in d ic a t e 95% co n fid e n ce in t e r v a l s

*

+

Age (days)

«

PROPORTION OF TOTAL COUNTS RECORDED ON THE LIGHT-HALF OF THE CHOICE CHAMBER o o o o o o o o o o o o o o o o o o o o o o

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all had been deposited on the cloth on the dark side of the chambers.

2.3.4 Larval humidity discrimination

The data were analysed using a standard arcsine transformation. The proportion of larvae on the side with the highest humidity was arcsine transformed (sin J %/100 ), and subjected to analysis of variance. The data for each replicate were subdivided into four 30 minute intervals to enable time to be used as an additional factor in the analysis of variance, in order to determine if there was a change in the intensity of response during the test period. The intensity of response to a humidity gradient may be due to the difference between any pair of humidities tested, rather than to their absolute values, therefore a second analysis of variance was performed on humidity differences. Table 2.3 shows the mean percentages and effective standard errors of means of larvae on the side of highest humidity for the different factors tested, and their associated anovar tables.

Whether larvae were preconditioned to 30 or 70% rh before the start of the experiment did not have any significant effect upon their reaction to the humidity gradients tested. However,larvae did respond to a gradient and generally aggregated on the side of lowest humidity (Figure 2.8a). The intensity of response was affected significantly by the difference between any pair of humidities presented - the greater the difference the more pronounced the response toward the lowest humidity (Figure 2.8b). For most combinations the intensity of response toward the lowest humidity increased with time of exposure to the experimental conditions, except for the 30-50% rh gradient where the converse was true (Figure 2.8c).

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(a) Humidity gradients

Humi dity grad i ent30/5030/7030/9050/7050/9070/90

Pretreatment: 3055 rh Pretreatment: 70% rhTime interval (mins) Time interval (mins)

0-30 30-60 60-90 90-120 0-30 30-60 60-90 90-12040.4 41.7 43.0 42.5 38.8 40.7 45.8 44.835.8 35.9 33.4 32.8 40.7 38.2 35.7 33.235.7 34.4 34.1 33.4 25.8 24.7 26.2 26.338.5 39.8 36.6 38.8 41.9 39.7 37.5 36.637.9 37.0 35.3 32.9 40.4 36.0 31.8 30.940.1 37.2 34.7 33.6 40.9 39.9 35.7 37.2

Effective standard error = 10.09

Source S.S. d.f. S.S.% M.S. F-ratioHumidity. . . 13784.1 5 29.2 2756.8 36.5 ***Pretreatment. . . . P 63.9 1 0 . 1 63.9 0.8 N.S.Time........ . . . T 1264.9 3 2.7 421.6 5.6 ***H.P 3177.8 5 6.7 635.6 8,4

H.T 2751.5 15 5.8 183.4 2,4 *■**P.T 46.6 3 0 . 1 15.5 0.2 N.S.H.P.T 770.0 15 1 . 6 51.3 0.7 N.S.Res i duaI 25347.3 336 53.7 75.4Tota I 47206.1 383 1 00. 0 123.3

(b) Humidity differences

Humi dity diff.

Pretreatment: 30% rh Pretreatment: 70% rhTime interval (mins) Time interval (mins)

0-30 30-60 60-90 90-120 0-30 30-60 60-90 90-12C20 39.7 39.5 38.1 38.3 40.5 40.1 39.8 39.640 36.9 36.4 34.4 32.9 40.5 37.1 33.8 32.160 35.7 34.4 34.1 33.4 25.8 24.7 26.2 26.3

Effective standard error = 9.20

Source S.S. d.f. S.S.% M.S. F-ratioHumidity difference HD 11450.1 2 24.3 5725.0 68. 1 ***Pretreatment. . . . P 63.9 1 0 . 1 63.9 0.8 N.S.Time............. T 1264.9 3 2.7 421.6 5.0 **HD. P 2855.9 2 6 . 1 1427.9 17.0 ***HD.T 926.3 6 2 .0 154.4 1.8 N.S.P.T 46.6 3 0 . 1 15.5 0.2 N.S.HD.P.T 319.3 6 0.7 53.2 0.6 N.S.Residua I 30279.2 360 64.1 84.1Tota I 47206.1 383 1 00. 0 123.3

Key ** significant at p ^ 0.01, *** significant at p ^ 0.001, N.S. no significant diff.

Table 2.3 Larval humidity discrimination data. Tables of percentage means of larvae in high humidity, their effective standard errors and analysis of variance results.

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Figure 2.8 Larval humidity discrimination

(a) Effect of humidity gradient on the mean percentage response of larvae aggregating on the side of highest humidity.

(b) Effect of the difference between pairs of humidities on the mean percentage response of larvae aggregating on the side of highest humidity.

(c) Effect of time of exposure to the experimental conditions for the six different humidity combinations and the pooled data, on the mean percentage response of larvae aggregating on the side of highest humidity.

*

♦

MEAN

% R

ESPO

NSE

TO H

IGH

HUMI

DITY

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*

PRECONDITION HUMIDITY: PRECONDITION HUMIDITY:

LnO • v jo kDo o vDo K Do LnO o vDO ■vjOHumidity gradient

PRECONDITION HUMIDITY: 30% rh

PRECONDITION HUMIDITY:

#

Humidity difference

50/90

MEAN

% R

ESPO

NSE

TO H

IGH

HUMI

DITY

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&

#

30/50

42

40 -

38

36 -

50/70

» » »0-30 30-60 60-90 90-120

40

38

36

34

32

0-30 30-60 60-90 90-120

30/90

Time interval

70/90

_______ i_______ i_______ « i

0-30 30-60 60-90 90-120

(mins)

c.Figure 2.8 (contd)

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2.4 Discussion2.4.1 Sex pheromone releasing behaviour

The response of males to disks previously exposed to calling females clearly indicates that material capable of illiciting mating behaviour in males, has been transferred to the filter paper. Similar male responses to disks exposed to calling females were observed by Burkholder oX a t . 1974) for A . lavipe.6. They found that 90% of males responded to disks exposed to females while none responded to disks exposed to males or to control disks. Their experimental procedure differed slightly in that the bioassay males were tested either with disks exposed to males, females or unexposed (control) disks. In the present study males were provided with an exposed plus a control disk in the arenas at the same time. The low response to control disks always occurred immediately following an initial response to the disk exposed to a calling female, and was therefore considered to be an 'overspill' reaction toward the latter.

A . 60LtivuLc.ut> calling behaviour was observed for lOhrs, starting 2%hrs into the photophase, whereas calling by k. la.\jX,p<u> was observed only for the first 4hrs of the photophase, with peak activity at l%-2hrs (Ma & Burkholder, 1978). The response of male A . 6an.YiJic.ii6 to disks exposed to females was closely correlated with female calling behaviour, although from the design of this experiment an additional and unavoidable variable was introduced, which was the possibility of daily periodicity in male response to sex pheromone. In order to pursue this aspect further a standard pheromone source would be required, necessitating identification of the active pheromone constituents). Perhaps ideally male response should have been tested by extracting the pheromone from groups of females at given times of the day and the extracts bioassayed with males at a standard time period. However, with regard to the time required for the development and standardisation of such procedures, it was felt that the methods adopted, which followed more closely the natural sequence of events, were adequate for preliminary experiments. Ma & Burkholder (1978) showed that male k.^lavL po ,* responsiveness to a fixed concentration of pheromone varied during the course of the day, but overlapped the time period of peak calling activity. Similarly in Tfiogoddfima.

*

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tnc.lu6um LeConte & T.glabnum (Hbst), a plateau of male responsiveness was observed 4-8hrs into the photophase, which declined after about lOhrs (Vick at a£.,1973). Periodicity of male response is not always the case in insects, Marsh (1975) for example, did not find any difference in male responsiveness of the aphid Megoit'ta vtataz Buck., throughout the light phase of a 12:12LD regime.

It could also be argued that the decline in male responsiveness after 8^hrs into the photophase could have been due to habituation to pheromone odour. Because of a shortage of stock insects the same batches of males were assayed with disks for 1 minute intervals every %hr. Adams at at .,(1975) found that the response of male A.vznba.6ct to n-undecanoic acid ceased after 30-60 minutes exposure and considered this to be due to olfactory habituation. Vick at at., (1973a) found that a 1 minute exposure to synthetic pheromone was sufficient to habituate males of T.tnc.lu.6um and resulted in a diminished response to subsequent doses of the pheromone for at least 4%hrs. The concentration of pheromone used however, was at least double that of the natural pheromone required to elicit a 50% male response and therefore their results may not be indicative of a normal habituation response. It seems unlikely that habituation occurred in the present investigation as the pattern of male response followed closely that of female calling activity and even after the same males had been assayed 16 times, a 64% response was recorded.

The onset of calling behaviour was correlated with the attainment of sexual maturity. Calling activity increased with age and reached a maximum at 3-4 days which corresponded with the period of peak oocyte maturation and presence of sperm in the spermatheca, indicating successful mating (Section 1.3.16). Similar phenomena have been observed in other stored products insects, for example La6todoArna 4eA'iXco'me (F.) pheromone was not released until females were at least 12hrs old, and the peak of this activity occurred at 4-5 days coinciding with the attainment of sexual maturity (Coffelt & Burkholder, 1972). In Tandbnto molttox. L., too the rate of pheromone emission increased markedly in the first 5 days of active life (Happ & Wheeler, 1969), mating was observed at 4 days and by the 5th day most matings had resulted in successful spermatophore transfer (Happ,

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2.4.2 Olfaction experiments

Attractancy and repellency are often loosely used in the literature, though Dethier eX a t . ,(1960) defined an a tt^ a c X a n t as a chemical which causes orientated movements towards itself, and a >ie.peJtle.yX as a chemical which causes orientated movements of insects away from it. In addition they recognised two further terms, aw e.A tanX , which is a chemical causing insects to aggregate because it reduces their tendancy to move and hence to move away from it, and lo co m o to r s t im u la n t , a chemical which stimulates insects to move and hence, usually, to disperse from its neighbourhood. In the present investigation on odour detection, attractancy effects cannot be separated from arrestant, nor repellency from locomotor stimulant activity.Indeed it is likely that a considerable number of behavioural reflexes are involved resulting in aggregation in the most favourable part of the choice chamber. For simplicity, until more detailed studies can be undertaken, attractancy and repellency are used here as blanket terms for a resulting aggregation toward or away from the stimulus.

Starved larvae were attracted to the odours of potential food substances, with young larvae showing a greater response than mature larvae. Blake (1955), found that young larvae of k.ve.n.ba6cJi were attracted to the odours of "potential food components of the general bird nest smell” , and the response increased when larvae were starved for a day or two. She found that the response of mated females with increasing age to bird nest and Hogweed (Hesiac.le.um sp.) odour, fluctuated rhythmically and was to some extent correlated with oviposition. Peaks of attraction to nest odour were correlated with peaks in oviposition and peaks of attraction to Hogweed odour with troughs in oviposition, although in a repeat experiment some years later she was unable to confirm these results. In the present study with A .6an.YiJLc.UL6, the beetles were of differing ages, which maybe why mated females were not significantly attracted to potential larval foods, as a proportion may have oviposited prior to testing and thus may not have been attracted by oviposition site odours, As Busvine (1971) points out, tests on repellency and attraction are comp-

1970).

«

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licated by the fact that a number of entities are involved; the insect (age, physiological condition etc.), the attractive site and the repellent/attractant, all of which may be modified by environmental conditions.

As young larvae showed a strong positive response toward potential food odours, it could be that it is this stage which finds its way into museum collection material rather than adults ovipositing directly on the artefacts themselves. Indeed a preliminary experiment not described in this thesis showed that adult females preferred to oviposit in cracks and crevices or in fibrous material such as cotton wool, which has no food value to the larvae, rather than oviposit directly on dried beetles or fishmeal. Blake (1955) also found that k.vQjiba&cjL laid significantly greater numbers of eggs in fibrous materials rather than granular substrates.

Both napthalene and PDB were strongly repellent to all active life stages. The concentrations of these chemicals in the vapour phase were unknown, so it was not possible to make direct comparisons regarding effectiveness in terms of quantal responses, but it was considered that the quantities in the vapour phase would be comparable to those which would be found in a museum insect storage case where an excess of the solid phase was present. However, the tests did not properly simulate museum conditions, where larvae may become habituated to sublethal concentrations of repellent odours, or starved larvae may become increasingly tolerant to repellents. Indeed Billings (1934) considered that PDB and napthalene had no discemable repellent effects to the clothes moth, Tlne.o la biAAdJUUzZla. (Hum), and were acting merely as vapour poisons. Abbott & Billings (1935) tested their effectiveness against the clothes moth under household conditions and showed that neither prevented adult moths from entering open closets and ovipositing, or larvae from feeding on flannel cloth. In museums many workers consider napthalene and PDB to be ineffective as repellents or poisons against An£/yien£i4 (pers., observation). Clearly if an excess of the solid phase is not present or boxes are not sufficiently air-tight thereby preventing adequate vapour phase concentrations being maintained, it is unlikely that these relatively low potency chemicals

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will be effective. If adequate concentrations can be maintained in sealed boxes, then both act as vapour phase insecticides (see Part III), but it is clear too from these behavioural tests that the insects also avoid or are repelled by the substances.

2.4.3 Phototactic response of adult beetles

Blake (1955) investigated the phototactic response of A.veAba4c.<L when orientating to a point source of light, and found that virgin females became positive to light at a much earlier age (5 days old), than mated females (12 days old). Such a trend was not evident in A.6asiruxLu4 where groups became photopositive at roughly the same age (9 days old). Dissection of beetles collected at windows confirmed that the vast majority of females were at least 9 day old mated beetles, and the small proportion of beetles which had not previously oviposited had very little fat body, indicating that they were at least 10-20 days old (Section 1.3.16). Interestingly in mated females the increase in response to light quickly followed the onset of oviposition. Oviposition in unfed females at 20°C started on day 5 and by day 8, 96% had laid their first egg batch (Section 1.3.14), correspondingly the number of beetles becoming photopositive increased from 29% on day 6 to 70% on day 10. This response differs markedly from A ,v(L>iboL6c.X, when mated females were photonegative during periods of oviposition and reverted to a photopositive phase after egg laying (Blake, 1955). However Blake's insects were tested individually and she found considerable variation in the response of individuals and only achieved a good correlation with oviposition when those individuals which were completely indifferent to light were disregarded from the analysis.

Blake considered that switching of phototactic response was advantageous to the species in terms of increasing fecundity through mating success and dispersal. As Anth.tie.nu.4 are generally low density insects in view of the limited food resources that their natural habitats offer, many adults will emerge in isolated places. It is likely that females remain in the vicinity of where they pupated for several days, releasing sex pheromone to attract nearby males, if mating is unsuccessful then there is a rapid transition to pos-

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itive behaviour where aggregation on flowers will increase the chances of mating and where feeding on flowers will increase fecundity of females and longevity of both sexes (Section 1.3.14). As mated, gravid females become photonegative, and orient by currently unknown behavioural mechanisms to habitats suitable for oviposition and larval development, it is unlikely that they will return to the location from where they emerged, but will disperse to start new infestations. Adults derived from large thriving infestations are more likely to achieve successful mating within the first few days of active life, therefore females will oviposit their first egg batch at the same location from where they emerged. Unfortunately this explanation makes it difficult to interpret why unmated females should remain photonegative as long or longer than mated females, and adds doubt to the conclusion made earlier that the switching of phototaxis is related to oviposition and mating, clearly these points need further clarification, particularly since a repeat experiment by Blake (1955), where the response of batches of 6 beetles tested simultaneously gave results similar to the present investigation, where there was a rapid rise in the proportion of females becoming photopositive after 8-10 days.

Increasing response to light with age is a common phenomenon in stored products insects. For example, both mated and unmated males and females of T n J L b o L L u m c a . 6 t a n e . u m (Hbst) & T . c o n ^ u 6 u m duVal, exhibit this behaviour which Arbogast & Flaherty (1973) considered to be correlated with the onset of reproductive maturity. Mated T . c a 6 t a n e . u m were becoming more photopositive than unmated males and females, but this was less well marked in T . c o n ^ u 6 u m .

#2.4.4 Larval humidity discrimination

The results of the larval humidity experiments show that late instarK . 6 a n . n X j c u 6 larvae are hygronegative, as are most stored products insects by virtue of the kinds of habitats they exploit. T . m o Z J L t o n (Pielou & Gunn, 1940), T . c a 6 t a n c u m (Willis & Roth, 1950) and P t t n u 6 t c c t u . 6 (Bentley, 1944), are all species which live in dry environments and have been shown to prefer the drier of any two humidity alternatives. The hygronegative reaction in k . 6 a n . n t c u 6 became more pronounced the steeper the humidity gradient, similar results were

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obtained by Pielou & Gunn (1940) for T.m o& Xoti. Some pests of stored grain however have been shown to be hygropositive. For example adults of 0>iyzcLQ.phJJ.u.t> 6u'iAJiamm6'U> (L.) (Stubbs & Griffin, 1983), and SXXophJJ.u.4 gn.anoLfULu.4 (L.) (Smereka & Hodson, 1959), tend to aggregate in moist grain which is more favourable for development and oviposition in these species. Most authors considered that movement to preferred conditions was purely by orthokinesis, although Stubbs & Griffin (1983) suggested that 0 . 4 iinJunam<iyi4jL4 orientated (klinotaxis) towards a higher humidity.

Preconditioning of insects at low or high humidity may affect their reaction to a humidity gradient. This was not apparent for A . 40Ln.nJic.vL4 in the present investigation, but Bentley (1944) found that if adults of Vi.Xjnu.4 to,c.ta4 were desiccated the strong reaction towards drier air disappeared and was replaced by aggregation in regions of higher humidity. Similarly Stubbs & Griffin (1983) found that the humidity to which adults of 0 . 4mJLYiamo,YL4Ji4 were preconditioned affected their response to water, but even those preconditioned at 100% rh were attracted to the water source.

The choice chamber method for testing humidity reactions is not ideal as it results in a sharp boundary between humidities, a gradually changing gradient is probably much nearer to the situation which would be encountered in the field. Differences in results in the literature on the response of 0 . 4u>iXjiamzn4XJi to humidity have been discussed in relation to these two different test methods (Stubbs & Griffin, 1983).

*

2.5 Summary

Some preliminary studies on aspects of the behaviour of A.4oytttLcu4 which might be important, particularly in relation to the development of infestations and in the planning of control strategies are described.

1. The headstand posture exhibited by adult females was correlated with the release of sex pheromone. Calling behaviour began 2% hours after 'lights-on', reached a peak at 8 \ hours and ceased after 12\ hours.Male response to bioassay disks exposed to females followed the same trend as female calling behaviour. The onset of calling behaviour was correlated with the attainment of sexual maturity.

2. Olfactometer experiments showed that young larvae were attracted to odours derived from animal products, but were indifferent to the odours of plant derivatives. None of the test substances were highly attractive to late instar larvae and mated and virgin females were indifferent to the odours of dried beetles and birds' nest material. Naphthalene and PDB were strongly repellent to all life stages.

3. The influence of age, sex and mating condition upon the light responses of adult A .4a.JinjLc.u4 were investigated using light-dark alternative chambers. Mated and unmated females were photonegative for the first8 days of active life after which both groups became rapidly more photopositive. The reaction of mated males was more variable, but tended to become increasingly photopositive with age.

4. The humidity preferences of late instar larvae of A.4amicit4 were studied using alternative chambers. The humidities presented in all possible pairs in the chamber were 30, 50, 70 & 90% rh. Larvae were able to discriminate between the two different humidity levels and generally exhibited a hygronegative response. The greater the difference between any pair of humidities, the more pronounced the response toward the lowest humidity. The intensity of response toward the lowest humidity generally increased with time.

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PART III

CHEMICAL CONTROL STUDIES

3.1 Introduction

Infestation of museum insect collection material by dermestid beetles and k . 6CLn.YvLQ.iLt> in particular, have been of concern to the authorities of the BM(NH) for many years. Because of the lack of efficacy data on the use of pesticides in museums, the only regularly used insecticide for the prophylactic treatment of insect drawers and boxes in the BM(NH) was naphthalene. Application of this chemical alone proved inadequate to prevent a sudden increase in k .4 a 'in tc u 4 in the early 1980's, and chemical and pest control companies, approached for advice on the problem, could provide little information on the application of pesticides to potentially very sensitive materials which could easily be damaged by the chemicals themselves or by inappropriate application methods. Such problems are not confined to the BM(NH) alone, museums worldwide are faced with insect pest problems. The range of pest species is very large, Beauchamp oX al.,(1981) listed 96 species in the U.S.A., although the particular pest species in individual museums depends upon climate, geographical location, specimen storage conditions and to some extent the local insect fauna. A status report by the Association of Systematics Collections of the U.S.A., stated that, "research’is desperately needed to determine the relative effectiveness of various pesticides and non-chemical pest control methods" (Edwards oX at., 1981). Unfortunately, at present few museums have easy access to professionals formally trained in the use of pesticides, and generally curators are unaware of what is legal, safe and effective, or even how pests are being controlled at other institutions or even in other areas of their own institution. In a survey of American natural history museums about 40% of curators admitted that tradition was the reason for using chemicals such as naphthalene and paradichlorobenzene (PDB), and over 50% of respondents did not express any opinion on pesticide hazards or the chemicals they preferred to use. This lack of response was considered to reflect the fact that many curators are confused and naive

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about both toxicity hazards and the effectiveness of most chemicals (Bell & Stanley, 1981).

One of the major difficulties of pest control in natural history collections is that it is generally undesirable to apply insecticides directly onto the specimens to be protected. This means that volatile chemicals have to be used which evaporate over a period of time, killing the pests by fumigant action or by contact or ingestion of residues absorbed onto surrounding surfaces. The use of volatile chemicals in buildings may create a potential hazard to occupants through inhalation of airborne toxicants, greatly restricting the number of such chemicals that can be applied safely in museums without proper fumigation apparatus or hermetically sealed storage containers.

Camphor and beechwood creosote are two of the earliest volatile substances used to protect boxes and drawers containing insect specimens against pest attack, but have now largely been superseded by naphthalene and PDB (Busvine, 1966). Both of the latter chemicals are of low potency to fabric pests (Herrick & Griswold, 1931; 1933), and their efficacy-as repellents has been questioned (Bottimor, 1929; Billings, 1934; Abbott & Billings, 1935). Tannert (1960) and Spencer (1963) advocated the use of lindane crystals either impregnated onto filter paper strips or applied directly into boxes. Their results were extremely promising, 200mg of active ingredient impregnated onto filter paper (Tannert, 1960) or lOOOmg of crystals sprinkled on the floor of a drawer (Spencer, 1963), immobilised and eventually killed dermestid larvae and prevented others from becoming established for up to one year after treatment. Neither method appears to have been adopted by museums, possibly because of the relatively high mammalian toxicity and pungent odour of lindane, and in fact, in a recent bibliography of the literature pertaining to museum pest control, these papers were not included (Stanley, 1981).

Slow release formulations of dichlorvos are quite frequently used in museums, usually in the form of PVC strips impregnated with active ingredient. For museum use the commercially available slow

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release units such as 'Vapona' (Temana U.K., Ltd.), are usually cut into smaller pieces for use in small volume storage containers such as insect drawers. The use of dichlorvos slow release units in bird skin cabinets and display cases at Tring Museum, Hertfordshire, U.K., has been investigated by Scudamore a t . , (1980).

This resume of relevant papers indicates how little research has been carried out on the use of pesticides in museums. Where insecticides are used, the concentrations required, the length of time a treatment will remain effective, and the potential health risks are usually unknown. The aims of this section of the thesis were to investigate the performance of chemicals under museum conditions with the intention of providing information which should facilitate the choice of suitable compounds for this particular application in the future. Particular emphasis was placed on determining vapour phase activity in relatively small enclosed airspaces, and persistence under such conditions. A number of compounds with relatively low mammalian toxicity were selected for investigation, from cypermethrin with negligible volatility (vapour pressure (v.p.)= 190 nPa at 20°C), to PDB, which is extremely volatile (v.p.=92 Pa at 20°C). Persistence of the contact and fumigant activities were determined by bioassay. Those insecticides which were found to be effective vapour toxicants were tested under simulated museum storage conditions, and two of these were used in the BM(NH) for a trial period.

♦

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3.2 Materials and Methods3.2.1 Culturing procedures for bioassays

Most bioassay experiments were carried out with A . 6la.vjLpe.6, since its development time of 5-7 weeks under optimum conditions enabled greater numbers to be reared than was possible with A . 6a.^yuic.ii6.Early instar larval stages were used for most of the bioassay work, partly because it was considered unlikely to be the larger larvae which invaded collection material through small openings and cracks in cabinets and boxes, and partly because it was easier to obtain young larvae of a standard size category, as growth rate differentials were not as apparent as in the late instars. Larvae of known age and fairly uniform size distribution (1.5-2.Omm), were obtained by confining 100-300 adults from stock cultures (see Section 1.2.5), at weekly intervals in plastic boxes (26 x 15 x 9cm), and providing them with a piece of old undyed woollen blanket material (25 x 14cm), upon which to oviposit. The boxes were kept in an incubator at 30 + 1°C, 70 + 5% rh, in constant dark. After one week the beetles were removed, the cloth dusted with approximately 2gm of dried yeast, and returned to the incubator. After a further 3 weeks, by which time larvae had attained the 2nd-3rd instar stage (Herfs, 1936), they were used for bioassay. Larvae were taken from the culture boxes for a 5 day period, serial cultures being available at weekly intervals. For bioassays using A .6(in.YUJLa6 and k.vz.n.boL6c.Ji, the appropriate developmental stages were taken from the monthly serial cultures (Section 1.2.5).

3.2.2 Insecticides

The following compounds were used in the study, vapour pressures and toxicities, with the exception of empenthrin, are from Worthing & Walker (1983). Situations for which commercial clearance has been granted in the U.K., under the Pesticides Safety Precautions Scheme (PSPS) for use in buildings, is taken from the Ministry of Agriculture, Fisheries and Food information sheet, "Contact insecticides for use against storage, domestic and hygiene pests", March 1983.

#

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ORGANOCHLjORINE(1) Lindane: benzene hexachloride (£T -isomer > 99% m/m).

v.p.= 1.3 mPa at 20°C. Rat acute LD^q , oral: 88-270 mg/Kg, percutaneous: 900-1000 mg/Kg. Formulation: technical$ -isomer 99.0%.I.C.I. Plant Protection Div., pic. Clearance: general public - all uses.ORGANOPHOSPHORUS

(2) Azamethiphos: S-6-chloro-2,3-dihydro-2-oxo-oxazolo[4,5-6Jpyridin-3-ylmethyl 0 ,0 -dimethyl phosphorothioate.v.p.= 4.9 uPa at 20°C. Rat acute LD^q , oral: 1180 mg/Kg, percutaneous: > 2150 mg/Kg. Formulation: technical 94.2% a.i. Ciba-Geigy A.G. Clearance: trained operators - animal husbandry only.

(3) Bromophos: 0-4-bromo-2,5-dichlorophenyl 0,0-dimethyl phosphorothioate.v.p.= 17 mPa at 20°C. Rat acute oral LD^: 3750-8000 mg/Kg. Formulation: technical 98.0% a.i. Boehringer Ingelheim. Clearance: general public - all uses.

(4) Chlorpyrifos-methyl: 0,0-dimethyl 0-3,5,6-trchloro-2-pyridyl phosphorothioate (I).v.p.= 2.7 mPa at 20°C. Rat acute oral LD^: 1630-2140 mg/Kg.Formulations: technical 99.5% a.i., 'Reldan' 50% e.c . Dow Chemical Company. Clearance: trained operators - food storage only.

(5) Diazinon: 0,0-diethyl 0-2-isopropyl-6-methylpyrimidin-4-yl phosphorothioate.v.p.= 18.7 mPa at 20°C. Rat acute LD^, oral: 300-400 mg/Kg, percutaneous: > 2150 mg/Kg. Formulation: technical 90.0% a.i. Ciba-Geigy A.G. Clearance: general public - household, public hygiene, food storage.

(6) Dichlorvos: 2,2-dichlorovinyl dimethyl phosphate (I).v.p.= 1.6 Pa at 20°C. Rat acute LD^q , oral: 56-108 mg/Kg, percutaneous: 75-210 mg/Kg. Formulation: technical 96.0% a.i. Shell Chemical Co.,Ltd. Clearance: general public - all uses.

(7) Iodofenphos: 0-2,5-dichloro-4-iodophenyl 0 ,0-dimethyl phosphorothioate.v.p.= 106 uPa at 20°C. Rat acute LD^q , oral: 2100 mg/Kg, percutaneous: > 2000 mg/Kg. Formulation: technical 96.9 % a.i. Ciba-Geigy A.G. Clearance: general public - all uses.

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(8) Pirimiphos-methyl: 0-2-diethylamino-6-methylpyrimidin-4-yl 0,0- dimethyl phosphorothioate.v.p.= 3.6 mPa at 20°C. Rat acute oral LD^: 2050 mg/Kg.Formulation: technical 90.3% a.i. I.C.I. Plant Protection Div., PLC. Clearance: general public - all uses.FYRETHROID

(9) Cypermethrin: (RS)-^-cyano-3-phenoxybenyzyl (1RS,3RS; lRS,3SR)-3- (2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate; (RS)-% - cyano-3-phenoxybenzy1 (IRS)- cJu-£>uiru -3-(2,2-dichloroviny1) -1,1 - dime thylcyclopropanecarboxylate.v.p.= 190 nPa at 20°C. Rat acute oral LD^: 251-4123 mg/Kg. Formulation: technical 73.0% a.i. I.C.I. Plant Protection Div., PLC. Clearance: trained operators - food storage and public hygiene.

(10) Empenthrin: (RS)-l-ethynyl-2-methylpent-2-enyl (lR)-cX^, tn.<m6- chr y s an thema t e.v.p.= 144 mPa at 20°C (extrapolated). Mouse acute oral LD^q : 2870- 2940 mg/Kg. Formulations: technical 91.4% a.i., 'Vaporthrin Mothproofing Strip' 500 mg a.i./paper. Sumitomo Chemical Co., Ltd. Clearance: not cleared to date by PSPS.

(11) FMC 54800: fumigant pyrethroid. (Chemical name not available).Rat acute oral LD^: approx., 200 mg/Kg. Formulation: 10.0% a.i. formulation. May & Baker Ltd. Clearance: not cleared to date by PSPS. MISCELLANEOUS

(12) Naphthalene: naphthalene.v.p.= 6.5 Pa at 20°C. Rat acute oral LD^: 2200 mg/Kg.Formulation: 100% a.i. crystals. Koch Light Labs., Ltd.Clearance: not listed.

(13) Paradichlorobenzene (PDB): 1,4-dichlorobenzene.v.p.= 92 Pa at 20°C. Rat acute oral LD^: 500-5000 mg/Kg.Formulation: 99.8% (min) a.i. crystals. BDH Chemicals Ltd.Clearance: not listed.

Based on the World Health Organisation tentative classification of solid and liquid formulations of pesticides by hazard (Papworth,1975), which recognises the greater risks that may arise when formulations are used as liquids compared with dusts, most of the insecticides in this list fall in the classes 'moderately hazardous' or'slightly hazardous' (i.e. oral LD^Q(rat) >, 200mg/Kg & percutaneous LD^Q(rat) 400mg/Kg). Only lindane and dichlorvos fall in

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the ’highly hazardous' class (i.e. oral LD^Crat) < 200mg/Kg), when used as liquid formulations.

3.2.3 Persistence of fumigant and contact activities of pesticides

Assessments of the biological activity and persistence of each pesticide were carried out using a standardised bioassay procedure conducted in screw-capped glass scintillation vials (Spectravial 2, BDH Ltd.), with an internal volume of 25cm3. Insecticides were either applied directly to the internal glass surface of the vials or onto filter papers which were subsequently placed in the vials. Stock solutions in acetone (Pronalys, May & Baker Ltd.), containing 1% w/v of active ingredient and 0.2% v/v Shell Risella oil (R17), were prepared for each insecticide. As cypermethrin and FMC 54800 were supplied as oil based formulations, R17 was not added. These solutions were diluted further with acetone to give concentrations of 0.5, 0.25, 0.05, 0.025 & 0.005% w/v active ingredient. In addition a control solution was prepared containing 0.1% v/v R17 oil. This concentration of R17 was used because initial experiments had shown that 0.2|jl was the maximum amount of oil that could be deposited on the glass surface without causing control mortality. Higher concentrations resulted in the formation of discrete oil droplets in which early instar larvae became asphyxiated.

Insecticides were applied to glass surfaces by pipetting 200pl aliquots of solution into the vials using a Hamilton 250 Microliter® syringe. Vials were then placed horizontally on rollers, rotating at 75 revs/min., until the solution had evaporated to dryness, leaving an even deposit of insecticide on the internal circumferential wall. The six solution strengths gave the following deposits: 283, 142, 28, 14, 3 & 0 mg/m2.

Insecticides were applied to filter paper surfaces by pipetting 200pl aliquots of solution onto 4.25cm2 Whatman No.l filter papers. Treated filter papers were left to evaporate to dryness, and then placed into glass vials so that they pressed tightly against the inner wall. The six solution strengths gave the following deposits: 705, 352, 71, 35, 7 & 0 mg/m2.

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Each treatment was replicated four times with each insecticide and tested at successive time intervals for fumigant and contact activity. [NOTE: contact activity should more correctly be termed fumigant plus contact activity because the test insects were in contact with the deposit surface but mortality would also be influenced to a greater or lesser extent, depending upon the insecticide, by the vapour phase evaporating from the deposit surface]. Between assays the vials were stored uncapped at 25 + 1°C, 40-50% rh, in a 16:8LD photoperiod. Illumination was provided by three 125 watt fluorescent tubes in the ceiling. The light intensity received by the treated vials depended upon where they were stored on the shelves in the controlled temperature room, but was usually in the range 500-1000 lux during the light period. Larvae were transferred from the 30°C rearing incubator and acclimatised to the experimental temperature of 25°C, 24-48 hrs before the commencement of bioassay.

Contact activity was assessed by placing 10 larvae into each vial which were then closed with screw-caps and placed horizontally. Fumigant activity was assessed by placing 10 larvae into smaller h dram (27 x 9mm) glass vials, the open ends of which were closed with muslin held in place with copper wire ties. The muslin allowed free penetration of the vapour phase but prevented escape of the test insects. One such small vial was placed into each insecticide treated vial, the vial closed with a screw-cap and placed horizontally. After a 24 hr exposure period the larvae were transferred to 50 x 25mm glass tubes containing a small piece (15 x 10cm) of woollen blanket material as food and kept at 25°C, 40-50% rh for 3 days after which mortality was assessed. Larvae were considered dead when, under a low power dissecting microscope with bright illumination, they were unable to move away from the light source, and little or no movement was observed even after prodding with a fine needle.

Deposits were assayed at 0 days, 2-3 weeks and at 3-6 week intervals thereafter. Assays were discontinued after no mortality was observed in two consecutive tests.

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3.2.4 Persistence of insecticide deposits on 'Plastazote'

2.0ml aliquots of suitable insecticide concentrations in analytical acetone with 0.5% v/v R17 oil were pipetted onto 35 x 7cm sheets of Plastazote (cross-linked polyethylene sheet material, Wilford Manufacturing Co., Ltd., England), to give insecticide deposits of 100, 500 & 1000mg/m2 active ingredient. The solutions were spread well over the sheets thereby providing an even deposit after solvent evaporation. One sheet was prepared at each concentration with one control of 2.0ml acetone plus 0.5% R17 oil, for each insecticide. These deposits were bioassayed by placing 4 metal rings 54mm in diameter on each test sheet. The inside wall of the rings was highly polished to prevent escape of the test insects. Ten 2nd- 3rd instar A.^LavLpe-6 larvae were placed in each ring for 24 hrs, and kept for a further 3 days in glass tubes containing a small piece of woollen material before the assessment of mortality.

Fumigant activity was assayed only for those insecticides which had been demonstrated to have a vapour effect. Solutions of these in- scticides in acetone and R17 oil were prepared to give deposits equivalent to 100, 500 & 1000mg/m2 when 50pl aliquots were pipetted onto 20 x 15 x 7mm Plastazote segments. When dry the segments were placed in glass scintillation vials. There were 4 replicates at each concentration and for the controls. The fumigant bioassay technique, holding times and mortality assessment were as described in Section3.2.3.

3.2.5 Relative susceptibilities of Avith^Q,nu6 developmental stages to the contact and fumigant activities of insecticides

Mortality data for contact and fumigant activities of deposits of the selected insecticides on glass surfaces were obtained for the different developmental stages of A. LovLpe.4, A.4(W.vu,cu4 and K.\j<uibcL4(iL. A suitable dose range for each insecticide was determined from the initial assay of the persistence study (Section 3.2.3), Serial dilutions with analytical acetone were made from stock solutions, and 200pl aliquots were applied to glass vials. The handling procedures and mortality assessments were identical to those described in Section 3.2.3. Adults, early instar and late

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instar larvae were exposed in both the contact and fumigant tests, and also for some compounds effective in the vapour phase, fumigant activity was also assessed to eggs and pupae. Only late instar larvae of A.ve.tibcuc.jL were available in sufficient number for bioassay.

The early instar larvae of A.^LavLpe-6 were obtained from the cultures described in Section 3.2.1, other stages of A.^LavLpe.4 and all stages of k.t>OLKYiLc.u.A and k.ve,tiba.6CA, were obtained from the monthly serial cultures. Adults were 0-14 days old, no attempt was made to isolate the sexes. For early and late instar larvae ages were different for each species, thus: A. lla.vLpo.6, early (2-3 weeks), late (4-8 weeks); k.Aa'ivu.cu*, early (8-12 weeks), late (32-40 weeks); k.vzAbcLACJi, late (20-40 weeks). Where eggs were used these were 0-1 days old at the start of bioassay, laid by 1-14 day old adults on pieces of black woollen flannel (15 x 10mm). The number of eggs on each piece of cloth were counted, cloth plus eggs rolled-up and placed in \ dram (27 x 9mm) glass vials and treated thereafter the same as the other fumigant activity experiments. All bioassay material was acclimatised to 25°C, 40-50% rh for 24 hrs before starting an experiment.

3.2.6 Persistence of fumigant activity of insecticides in wooden boxes

Insufficient insect storage boxes or cabinet drawers from the museum were available for experimental use, therefore assay boxes with outside dimensions 20 x 15 x 5cm were constructed from 5mm exterior grade plywood. Panels were pre-cut to the appropriate sizes and glued together with 'Evo-stick' adhesive (Evode Ltd.).To ensure that there were as few gaps as possible in the construction the edges were further sealed with Resin'W' wood adhesive (Evode Ltd.). Lids were not attached but were held in pLace with elastic bands.At one end of the box a 50 x 35mm piece of Plastazote was stuck to the bottom.

Technical grades of insecticides were dissolved in analytical grade acetone containing 0.5% v/v R17 oil, to give concentrations of 0.5, 1.0 and 5.0% w/v active ingredient. Technical FMC 54800 was not available and a 10% formulation was used diluted to the same concentrations with acetone. In addition a 50% emulsifiable

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concentrate (e.c.) of chlorpyrifos-methyl (Reldan 50% e.c.), was tested for comparison with the technical grade active ingredient. 200pl of solution was pipetted onto 4.25cm diameter filter papers (Whatman No.l), which when dry were pinned into the boxes at the opposite end to the Plastazote with 37mm stainless steel entomological £>ins (No. 5). Four replicates were prepared for each dose, with four untreated controls of acetone and 0.5% R17 oil only.

To prolong the activity of naphthalene and PDB which were of low potency on impregnated filter papers, the standard procedure used in museums was adopted, where crystals of these compounds are placed directly into boxes at high application rates. The amounts used were 1.3, 2.6 & 5.2 gms per box.

The boxes were maintained at 25 + 1°C, 40-50% rh, and fumigant activity was assessed using acclimatised 2nd-3rd instar A .filavjLpe.* larvae subjected to two different assay conditions:

(i) Test insects freely exposed to fumigant. Ten larvae were placed in \ dram vials fitted with muslin closures over the open end, and one vial was pinned to the Plastozote in each box at each assay 'interval.

(ii) Test insects enclosed in insect cuticle. When large insect specimens are attacked by Antkn.znu.6 the larvae will often eat their way into the body of the specimen and feed from within this concealed position. It was of interest therefore to determine if the fumigant phases of the insecticides under test were capable of penetrating the cuticle of the specimens to be protected and be sufficiently toxic to kill the pest insect within..The pupal skin was removed from hatched puparia of C altipkon .a v o m it atiJLa. (L.) and five 2nd- 3rd instar larvae introduced into each using a fine camel hair brush. The open ends of the puparia were then sealed with a thin plug of paraffin wax (m.p. 60°C). Four prepared puparia (i.e. 20 larvae per replicate) were glued with water soluble gum (Watkins & Doncaster Ltd.), by their posterior ends to the long edge of a piece of Bristol board (25 x 5mm). One card with four puparia was pinned into each box at each assay time. Boxes were kept closed except for the brief intervals when assay tubes and puparia were inserted or removed. Vials and puparial cards were removed after

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48 hr exposure periods. Mortality was assessed after a 3 day holding period using the same criteria as outlined in Section 3.2.3.

3.2.7 Field evaluation of some candidate insecticides (i) Lindane

In May 1984 4.25cm diameter filter papers each impregnated with 56mg a.i. of lindane were pinned into 40 drawers of an 80 drawer insect cabinet at the BM(NH),containing Lepidoptera specimens.This cabinet had been infested frequently by A. •da'inLc.u* over the past 5 years. The internal volume of each drawer was approximately7.4 x 10 m3, thus the dosage rate of available insecticide was 7.5gm a.i./m3. Untreated drawers were left as controls, although some contained residues of naphthalene. The drawers were examined for signs of infestation at infrequent intervals by staff at the museum.

(ii) Chlorpyrifos-methyl

Reldan 50% e.c. was diluted with an equal volume of acetone solvent and 500pl aliquots containing 125mg a.i. were pipetted onto 10 x 2.5 cm strips of Whatman No.3 filter paper. After drying the strips were stored in ground glass stoppered jars. Approximately 1500 strips were prepared and pinned into insect drawers housing mainly Lepidoptera specimens, at the BM(NH), during June-July 1984. The in-_3temal volume of these drawers was approximately 7.5 x 10 m3, thus the dosage rate was 16.7gm a.i./m3. Drawers were not examined at specific time intervals but the presence or absence of infestations were noted by staff during normal curatorial procedures.

A more controlled test of Reldan 50% e.c. was carried out in the laboratory using wooden museum insect storage boxes (internal volume 6 x 10 m3), containing Lepidoptera specimens. Filter paper strips impregnated with 125mg a.i. were pinned into 4 boxes and forty 2nd-3rd instar A .6 clsuvLc.u4 larvae introduced into each. The boxes were kept closed for 5 days after which time a damage and mortality assessment was made. Further batches of 40 larvae were added to the boxes 10 weeks after treatment and mortality and damage again assessed after 5 days. Another 4 boxes were each

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inf es ted with 40 larvae but impregnated strips were not placed in each box until 10 weeks later. Mortality was assessed at 5 days and 14 days after the insecticide treatment. Two control boxes were set up with an acetone treated strip and 40 larvae added to each box.

An accelerated storage test was conducted with Reldan 50% e.c. to determine if there were likely to be any adverse effects on either the specimens to be protected or other components used in museum storage cases. Filter paper strips impregnated with 125mg a.i. were placed in six 0.91 ground glass stoppered cylinders (32cm long x 6cm diameter), capillary openings (3mm diam.) at either end of the cylinders allowed restricted exchange of air inside the vessels with the atmosphere outside. Untreated strips were placed in two of the cylinders as controls. A piece of Plastazote (10 x 5cm) pinned onto which were one brown and one yellow coloured butterfly specimen, assorted plated-brass, lacquered-brass and stainless steel entomological pins, polyporous strips, Bristol board mounting cards and good quality white paper were placed also in each cylinder. Three of the insecticide treated vessels and one control vessel were maintained at high humidity by placing a wad of cotton wool saturated with distilled water into the cylinders.The vessels were stored at 40 + 5°C for 5 months, after which the contents were examined for loss of quality in comparison with the controls. Maintenance of chlorpyrifos-methyl residues at 40°C for 6 months is equivalent to 2 years decay at 25°C (R.H. Lacey, Dow Chem., Co., pers. comm.).

(iii) Empenthrin

Vaporthrin mothproofing strips (Sumitomo Chemical Co., Ltd.) containing 500mg of empenthrin active ingredient per 87cm2 filterpaper strip, were evaluated for use in insect storage boxes of

-3internal volume 8.9 x 10 m3. Pieces of Vaporthrin strip containing 250, 125 & 65mg a.i. were pinned into the boxes. The quantities of a.i. used gave equivalent dosage rates of 28, 14 & 7gm a.i./m3 of airspace. Each concentration and a control containing untreated filter paper was replicated four times.

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Ten early instar A.^Tav-ipe* larvae were placed in \ dram vials with a 15 x 5mm piece of undyed pure woollen blanket material.The open end of the vial was closed with a muslin closure and two such vials placed in each box at each assay time. One vial was removed from each box after 48 & 120 hr exposure periods respectively and the woollen cloth examined and compared to the controls for signs of feeding damage. Usually the best indication of feeding was accumulations of frass in the vials. Larval mortality was assessed after a 3 day holding period.

*

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3.3 Results3.3.1 Persistence of fumigant and contact activities of pesticides

The dose response data were analysed by conventional probit analysis using the maximum likelihood iterative procedure described by Finney (1971), with the aid of the Imperial College Computer Centre facility. Table 3.1 shows the deposits required to give 50% kill of early instar A .^lavîpe.6 larvae when exposed for 24 hours to the fumigant and contact activities of the insecticides under test. As the deposits aged they generally became less active, as indicated by the increase in the LC^q values. Least squares regressions relating either LC^q or log LC^q to time after treatment were computed to determine if the rates of decay of insecticidal activity approximated to zero order or first order kinetics. Lines of best fit were determined from the computation of the coefficient of product moment correlation (r). If decay is zero order, i.e., the rate is independent of concentration, then a line of best fit will be obtained on a linear scale. If it is first order, i.e., rate is proportional to concentration, then the best fit will be on a semi-log scale. For a line of best fit on a linear scale the regression gradient is termed the loss rate or decay constant (mg/m2/week), and provides an index of the residual life of the insecticide under the test conditions (Carter & Chadwick, 1978). For a line of best fit on a semi-log scale it is implicit that the rate of decay is not constant, but an approximation of the mean rate of decay was determined from the slope of the chord between zero weeks and the number of weeks for which the last LCj-q was calculated. The results are tabulated in Table 3.2 with insecticides ranked in order of decreasing persistence for each experimental condition. For some treatments, both linear and semi-log fits were not significant. This generally arose in cases where the number of degrees of freedom for attaching significance to the correlation coefficient were small. In these cases a line of best fit was still computed and the rate of decay given in Table 3.2, although the corresponding 95% confidence intervals of the decay rate are large. Confidence limits could not be attached to first order rates of decay because these represent estimated mean values only. For most insecticides tested decay approximated to a zero order reaction rate, only PDB, naphthalene and diazinon were explained better by first order reaction kinetics.

Table 3.1 Estimated LC^q values (mg/m2) for early instarlarvae exposed to the fumigant and contact activity of residual surface deposits of insecticides.

Key I n s e c t i c i d e s : VAPO =DIAZ =BROM =PMET =CHLM =LIN =

I0D0 =AZAM =CYP =

FMC =

PDB =

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I i ndanei odophenphos

azamethiphoscyperme+hri n

FMC 54800parad i chIorobenzene

g la s s fumigant

g la s s c o n ta c t f i l t e r paper fumigant

f i l t e r paper c o n ta c t

( ) = 9 5 % co nf ide nce l im i t s*

1 0 2 3 6 7 10 n 12Age15

o f d e p o s i t (w e e k s ) 16 18 22 24 28 34 37 39 44 46 50

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(776)>01) - ‘f in - I I I !PMET GF

-

m l i , - - m - - - - - -(9£A .

55)53)GC

- - - - - - - - - - -n

- - -

MFF - [ i n i - - - - - - - -FC

M- (72.5) (79.2)

<H:9) S : h- - (102)

(^J:5) - - - - - -(72.9) (81(^:8) A

.8)-

(105)(13:2) - (130)

S : h

Table 3.1 (contd.)

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Age of deposit (weeks)0 0.14 0.29 0.43 0.57 1 2 4 6 11

NAPHTHALENE GF

m - ™GC

m - m; iwiFF m - m i : « ; «FC m - ii; ; « a s

PDB GF M IE, I W H I!GC 'M \ m , ' M I’il!FF m :i! !?i ! wFC <?«> <2?9> <?831>(U6.5) dll) (15?i) < 2ilh

DICHLORVOS GF (1 0 .3 ) (4580) (317646)( H) - - - - {1 hi, ( ioye,GC - - - - - !E> !11! MFF : « ............................ in, : « rn ;FC - ‘ttf W ‘SIS’ W( 6 .8 ) (7 1 .9 ) (167) (1464)

Table 3.1 (contd.)

-10Z-

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GLASS F LTER PAPER

In s e c t i c i de , ,FUMIGAN" mg/m /week

rR

, jCONTACI mg/m /week R

, , FUMIGANT mg/m /week R

, jCONTACI mg/m /week R

PDB 29723 s ( r= 0 .9 5 * )

7 24023 S (r= 0 .90 N .S )

13 11795 s ( r= 0 .9 7 * )

8 10429 S ( r= 0 .9 8 *)

12

NAPHTHALENE 32983 s ( r= 0 .9 8 * )

8 9814 s ( r= 0 .9 9 ** )

12 11673 s ( r= 0 .9 9 * * )

7 12261 s ( r= 0 .9 8 * )

13

DICHL0RV0S 5216 +_ 24268 ( r= 0 .9 3 N .S )

6 276 _+ 2123 ( r= 0 .86 N .S )

11 410 + 227 ( r= 0 .9 6 * * )

6 426 +_ 488 ( r= 0 .9 4 N .S )

10

EMPENTHRIN 272 + 109 ( r = 0 .9 8 * * )

5 2 .4 _+ 0 .7 ( r = 0 .9 8 * * * )

5 233 + 327 ( r= 0 .9 1 N .S )

5 4 .6 + 3 .0 ( r= 0 .9 4 * )

4

DIAZ I NON 158 s ( r= 0 .8 8 * )

4 230 s ( r= 0 .9 8 ** )

10 221 s ( r= 0 .9 0 * )

4 129 s( r = 0 .9 1 * * )

9

BR0M0PH0S - - 3 .6 + 1.4 ( r = 0 .9 2 * * * )

7 - - 7 .7 + 2 .8 ( r= 0 .9 2 * * * )

6

PIRIMIPH0S-METHYL 12.6 _+ 4 .8 ( r= 0 .9 6 * * )

2 1.1 + 1.4 ( r= 0 .8 0 * )

4 2 4 .0 + 39 .3 (r= 0 .7 5 N .S )

2 0 .5 + 0 .5 ( r= 0 .6 8 N .S )

1

CHL0RPYRIF0S-METHYL 17 .0 _+ 8 .6 ( r = 0 .9 1 * * )

3 6 .2 jf 2 .0( r= 0 .9 6 * * * )

8 4 7 .4 +_ 2 0 .0 ( r = 0 .8 9 * * * )

3 3 .4 + 1.5 ( r = 0 .8 9 * * * )

3

LINDANE 9.1 _+ 3 .3 ( r = 0 .9 5 * * * )

1 36 .8 + 4 8 .8 ( r= 0 .8 1 *)

9 1 2 .0 +_ 5 .9 ( r= 0 .8 2 ** )

1 2 .8 _+ 0 .9 ( r= 0 .9 2 * * * )

2

I0D0PHENPH0S - - 2 .6 + 1.3 ( r= 0 .8 5 * * )

6 - - 2 2 .0 + 9.1 ( r= 0 .8 8 * * * )

8

AZAMETHIPH0S - - 0 .5 +_ 0.1 ( r= 0 .9 9 ** )

2 - - 2990 + 3704 ( r= 0 .9 2 * )

11

CYPERMETHRIN - - 0 .02 _+ 0 .03 ( r= 0 .51 N .S )

1 - - 4 .7 +_ 1 .8 ( r = 0 .9 4 * * * )

5

FMC 54800 - - 0 .6 +_ 0 .2 ( r= 0 .9 9 ** )

3 - - 16 .4 + 18 .0 ( r= 0 .9 2 * * )

7

Key R = rank (the lower the rank number the longer the residual life), ♦ s = best regression fit on a semi-log scale,

r = Pearson's coefficient of product-moment correlation,* = significant at p < 0.05, ** = significant at p < 0.01,*** = significant at p ^ 0.001, N.S = no sign., difference._+ = 95% confidence intervals.

Table 3 .2 Estimated rates of decay of insecticidal activity at 25°C

based on bioassay with A. auXpe-4 for deposits applied to glass and filter paper surfaces.

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Only insecticides with a vapour pressure greater than 1 mPa at 20°C possessed any fumigant effect. High vapour pressure however is not necessarily indicative of fumigant activity, as exemplified by bromophos which showed no vapour phase activity over the range of concentrations tested. Plots of log vapour pressure against log loss rate (Figure 3.1) resulted in significant straight line relationships between these two parameters for loss of fumigant and contact activity from glass and loss of fumigant activity from filter paper. The regression lines show that insecticides with high vapour pressures lose activity faster than those of lower vapour pressure. However this trend was not apparent for loss of contact activity from filter paper where a simple straight line relationship could not be fitted to the data.

3.3.2 Persistence of insecticide deposits on 'Plastazote1

Table 3.3 shows the median lethal deposits for A . ^ l a v j i p e . 6 larvae exposed for 24 hours to the fumigant and contact activities of technical preparations of the test insecticides applied to Plastazote, and the rates of decay of activity are given in Table 3.4. Dichlorvos, empenthrin and iodofenphos followed zero order kinetics, while diazinon, bromophos, pirimiphos-methyl, chlorpyrifos-methyl and lindane followed first order kinetics. In all cases loss of activity declined more rapidly on Plastazote than on glass or filter paper surfaces. Plots of log vapour pressure against log loss rate (Figure 3.2), resulted in significant straight line relationships indicating that persistence of fumigant and contact activity was partly dependant upon the vapour pressure of the compound, as previously determined for glass and filter paper surfaces in Section 3.3.1.

3.3.3 Relative susceptibilities of A n t k t i z n u A developmental stages to the contact and fumigant activities of insecticides.

The LC^q and LC^ estimates for 24 hour exposure of the three An th .s iz n u .4

species to the fumigant and contact activity of the test insecticides applied to glass vials are tabulated in Appendix V. In Table 3.5 the relative potencies of the fumigant and contact activities of the test insecticides to the different developmental stages of A.4a'uu,c.it4 and

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Figure 3.1 Plots of vapour pressure against rate of decay of of insecticidal activity (log^ scale)

(a) fumigant activity on a glass surface(b) contact activity on a glass surface(c) fumigant activity on a filter paper surface(d) contact activity on a filter paper surface

r = Pearson's coefficient of product-moment corr.

«

-205-

-2.4 -1.6 -0.8 0.0 0.8 1.6 -3.5 -2.5 -1.5 -0.5 0.5 1.5log mg/m2/week

♦ <*

0 1 2 3 4 5 6 7 8Age o f d e p o s i t

10 12 13 14(w e e k s ) 16 17 18 20 21 23 26 28 30 35

DIC CI E , H i l l ’

537:5)hEMP F

! ! (^9) - (99£(2?i

})!) - d

(!) (2200) ) (1!?l)C - - M

- (785(20<|)?) - d(

;) <2741))) C l l h

- (3369)- < mDIAZ F - - - - - - - h i; - - (2120) - < m - - (4547)

- i W hC - - - - H f;i! - - - ;e , - - (*58)43) - -

- I’111 - (2946)( ’* 8 ,BROM C -

- I’l l - - - - (7022) - (8563)(?6§S) - - - l i f lPMET F

;e , - - - - m - - I l f ! -- (1821)

« mC - - - - - - - IBS, - - 111 - - - (1416) ( ??$) HECHLM F in - Ill - - - - IE - 111 ' - | 1i | - (1472)

- c38> - - h i)) - HEC - - lM - - - - m - IE, - - 111 - (;('

945) 243) - - in - - HI!LIN F -

- m - - -m ,

- - Iff, - IE, - - 111 - - M lC - - IE, - - - \\\\\ - - Ilf - ;;e - - 111 - - m - IlllI0D0 Cm i - Ill, - - - - - IS?! - - ( * i ^ ) - - - (1^ ) - (2086,

<19 I h - HI!Key DIC=dichlorvos, EMP=empenthrin, DIAZ=diazinon, BROM=bromophos, PMET=pirimiphos-methyl, CHLM=chIorpyrifos-methyl, LIN=lindane, IODO=lodophenphos

F=fumigant activity, C=contact activity, ( )=9556 confidence limits.

Table 3.3 Estimated LC q values (mg/m2) for early instar A . ^ l a v l p e . 6 larvae exposed to the fumigant and contact activity of residual deposits of insecticides on Plastazote.

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-207-

I nsecticide , 2fu m ig a n tmg/m /week R 2C0NTACT

mg/m /week RDICHL0RV0S 9159 +_ 9321

(r=0.82N.S)6 2751 _+ 988

(r=0.997*)8

EMPENTHRIN 72.4 +_ 27.5 (r=0.979**)

4 117 _+ 25.0 (r=0.993***)

5

DIAZ I NON 70.7 s (r=0.954*)

3 76.9 s (r=0.979**)

3

BR0M0PH0S - - 197 s(r=0.72N.S)

7

PIRIMIPH0S-METHYL 84.3 s (r=0.914*)

5 75.1 s (r=0.993***)

2

CHL0RPYRIF0S-METHYL 46.7 s (r=0.927***)

1 84.9 s (r=0.944*"*"*)

4

LINDANE 70.7 s (r=0.957**)

2 191 s(r=0.999***)

6

I0D0PHENPH0S - - 41.7 +_ 9.0 (r=0.978***)

1

Key R = rank (th e lower th e rank number the longer th e r e s id u a l l i f e ) ,

s = b e st r e g re s s io n f i t on a sem i- log s c a l e , r = P e a rso n 's c o e f f i c i e n t of product-moment c o r r e l a t i o n ,* = s i g n i f i c a n t a t p 0 .0 5 , * * = s i g n i f i c a n t at p 0 .0 1 ,* * * = s i g n i f i c a n t a t p 0 .0 0 1 , N.S = no s i g n i f i c a n t d i f f e r e n c e .

* Table 3.4 Estimated rates of decay of insecticidal activity at 25°Cbased on bioassay with A .^ l a v ^ L p o .6 larvae for deposits applied to Plastazote.

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Figure 3.2 Plots of vapour pressure against rate of decay ofinsecticidal activity (log Q scale) for deposits on Plastazote surfaces.

r = Pearson's coefficient of product-moment correlation.

FUMIGANT A' Sarn"— CONTACT A. flavFUMIGANT - ---- pes- — CONTACTPDB A > E(0.77) > L(0.12)

E(1.48) > A > L(0.07)A > E(0.70) > L(0.15) E(1.48) > A > LC0.07) Ed.59) > A > L(0.28) Ed.83) > A > L(0.29)

A > E(0.54) > L(0.20)NAP A > E(0.93) > L(0.04)

A > E(0.60) > L(0.002)A > E(0.93) > L(0.04)A > E(0.60) > L(0.002)

E(2.34) > A > L(0.01) E(1.60) > A > L(0.0004)

E(1.17) > A > L(0.01) E(2.59) > A > L(0.004)

DICH A > E(0.84) > L(0.57) > 0(0.06) A > E(0.32) > L(0.16) E(1.52) > L(1.27) > A

A > L(0.26) > E(0.21) > P(0.002) L(3.67) > A > E(0.67) > P(0.0002)

A > E(0.31) > L(0.15) E(1.59) > A > L(0.71)

EMP A > E(0.88) > L(0.01) > P(0.003)A > E(0.33) > L(0.004) > P(0.001) A > E(0.15) > L(0.23) E(2.74) > L(2.53) > A A > E(0.66) > L(0.41)

A > E(0.36) > L(0.14)DIAZ A > E(0.31) > L(0.12) A > E(0.53) > L(0.07)

A > L(0.07) > E(0.02) A > E(0.46) > L(0.19) A > EC0.41) > L(0.12) L(2.01) > A > E(0.34)

PMET A > E(0.25) > L(0.14) A > E(0.42) > L(0.16) A > E(0.12) > L(0.07) A > E(0.88) > L(0.74)CHLM A > E(0.11) > L(0.07) > P(0.0002)

A > E(0.22) > L(0.04) > P(^)A > E(0.71) > L(0.17) A > L(0.38) > E(0.34)

A > E(0.10) > LC0.08) E(1.16) > A > L(0.33) E(1.01) > A > L(0.76)

LIN A > E(0.37) > L(0.16) > P(^c) A > E(0.58) > LC0.06) E(2.97) > A > L(0.69) A > E(0.66) > L(0.16)

' E(2.57) > A > LC0.08) E(2.06) > A > L(0.47)

I0D0 - E(5.61) > A > L(0.16) A > E(0.66) > L(0.02) - E(2.02) > A > L(0.06)

A > EC0.39) > L(0.02)CYP - A > E(0.01) > L(0.0007) - A > EC0.14) > L(0.0008)FMC E(1.35) > A > L(0.61)

EC1.00) > A > L(0.97) A > E(0.13) > L(0.0001) Ed.60) > A > L(0.66) E d . 75) > L( 1.65) > A A > E(0.69) > L(0.01)

Key PDB=paradichlorobenzene, NAP=naphthalene, DICH=dichlorvos, EMP=empenthrin, DIAZ=diazinon, PMET=pirimiphos-methyl, CHLM=chlorpyrifos- methyl, LIN=lindane, IODO=iodofenphos, CYP=cypermethrin, FMC=FMC 54800. A=adult, E=early ins+ar larvae, L=la+e instar larvae, P=pupae 0=eggs.* Where the hypothesis of parallelism was untrue the upper figures for each insecticide represent relative potencies based on LCvalues and the lower based on LC values.95

50

Table 3.5 Estimated potencies (in parentheses), relative to the adult stage,of the fumigant and contact activities of insecticides.

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- 210-

A . £ l a v £ p e . 6 are given. The estimated potencies are relative to the adult stage. For example, relative to the toxicity to adult beetles of A . ^ a s i v U c u * , the fumigant toxicity of diazinon was only 0.31 and 0.12 times as potent to early and late instar larvae respectively. Parellelism was tested by the method of Finney (1971) using a programme written by the Statistical Research Service of the Canada Department of Agriculture available through the Imperial College Computer Centre facility. Where the data fitted the hypothesis of parallelism only one potency estimate is given. Where the data contradicted the hypothesis, relative potencies were estimated from the LC^q and LCg^ values recorded in Appendix V. In general, where pupae were tested they were the most tolerant to fumigant toxicity, and the late instar larvae were more tolerant than adults and early instar larvae, to both fumigant and contact toxicity. The susceptibilities of adult beetles relative to early instar larvae varied between insecticides, testing conditions and whether potency was based on the LC^q or LC^ estimates.

Table 3.6 shows a comparison of the potencies of the insecticides to early and late instar larvae for the three An t k ^ a i u 6 species tested. The susceptibilities of the same developmental stage of the different species differed relative to each other between insecticides and whether potencies were based on the LC,-q or LC t- estimates. It is not therefore possible to make any general conclusions regarding the relative susceptibilities of the different species to the insecticides tested.

The potencies of the contact and fumigant activities of the insecticides relative to the insecticidal toxicity of naphthalene for the different life stages of the three A n £ lv i< in u .6 species are illustrated in Figure 3.3. Cypermethrin was in all cases the most potent contact insecticide, but the order of potency of the other insecticides differed between species and developmental stages.

3.3.4 Persistence of fumigant activity of insecticides in wooden boxes

Tables 3.7 and 3.8 show the percentage mortalities of A . ^ lo L v £ p o .6 larvae exposed for 48 hours to the fumigant activity of the test insecticides while being held in glass vials and fly puparia respectively. As the

-211

Insecticide Early instar larvae Late instar larvaeFUMIGANT CONTACT FUMIGANT CONTACT

PARADICHLOROBENZENE

S > F(0.96) S > F(0.28)

S > F(0.93) S > F(0.20)

S > FC0.87) F > SCO.48)

S > FC0.88) F > SCO.02)

NAPHTHALENE F > S(0.88) F > S(0.60)

F > S(0.95) F > S(0.73)

S > FC0.12) > VC0.11) S > VC0.25) > FC0.08)

S > FC0.21) > VC0.12) S > FC0.55) > VC0.42)

DICHL0RV0S S > F(0.49) S > F(0.29)

S > F(0.35) S > F(0.44)

S > FC0.88) > VC0.62) F > SCO.82) > VC0.12)

S > VC0.50) > FC0.34) S > VC0.25) > FC0.24)

EMPENTHRIN F > S(0.87) F > S(0.19)

F > S(0.44) F > S(0.71)

F > SCO.02) > VC0.01)F > SCO.003) > VC0.001)

F > SCO.44) > VC0.06) F > SCO.75) > VC0.02)

D1AZ1 NON S > FC0.24) S > F(0.56)

S > F(0.39) S > FC0.75)

S > FC0.65) S > FC0.57)

S > FC0.84) F > SCO.55)

PIRIMIPHOS-METHYL

S > F(0.60) S > FC0.74)

S > F(0.27) S > F(0.58)

S > FC0.67) F > SCO.6 8)

S > FC0.59) S > FC0.68)

CHLORPYR1F0S- METHYL

S > F(0.77) S > FC0.73)

S > F(0.19) S > F(0.47)

V > SCO.35) > FC0.33)V > FC0.10) > SCO.09)

S > FC0.63) > VC0.50) s > FC0.63) > VC0.59)

LINDANE S > F(0.98) F > S(0.98)

S > F(0.56) S > F(0.43)

S > VC0.58) > FC0.54) S > VC0.74) > FC0.32)

S > VC0.77) > FC0.61) S > VC0.28) > FC0.21)

1ODOFENt PHOS - S > F(0.30)

S > F(0.38) - F > SCO.09) > VC0.08) F > VC0.45) > SCO.14)

CYPERMETHRIN - S > F(0.78) F > S(0.38) - F > SCO.002) > V(0.0005)

F > V(0.004) > SCO.001)FMC 54800 S = F(1.00)

F > S(0.45)F > SCO.96) S > FC0.95)

S > VC0.96) > FC0.95) S > FC0.92) > VC0.92)

F > VC0.74) > SCO.34) V > FC0.82) > SCO.38)

Key F=A.fIavipes, S=A.sarn?cus, V=A.verbasci.Figures in parentheses are the potencies relative to the most susceptible species. For each insecticide upper figures represent potencies relative to the most susceptible species based on LC values and the lower based on LC values.50 95

Table 3.6 Comparative susceptibilities to insecticides of larvae of the different AY ith n .m u .t> species tested.

- 212-

Figure 3.3 Potencies of the contact and fumigant activities of the test insecticides relative to the insecticidal toxicity of naphthalene, for the different life-stages of the three A n t h ^ m u 6 species.

Key Insecticides: PDB = D ICH= EMP = D I AZ= PMET= CHLM= LIN = I 0D0= CYP = FMC =

parad i chIorobenzene dichlorvos empenthri n d i az i nonp i rimi phos-methyI chIorpyri fos-methyI i i ndane i odophenphos cyperme+hri n FMC 54800

Inse

ctic

idal

po

tenc

y re

lati

ve to

na

phth

alen

eA. SARN1CUS

FUMIGANT

1x10.10

1x10

1x10*

1x10'

1x10^

1000

100

10

ADULTS EARLY INSTAR LARVAE

CONTACT

n o m a TJ o r* ___ o *"n u a *m o n O i- ■na — 2 — < X — o -< 2 a — < — ■< X — o 2UJ o u > m r- z o TJ o 00 o ~o > m r- z o Tl C 5x Nl —i 2 o X N H 2 o

A l/ERBASCI

LATE INSTAR LARVAE

IK> I—k U> I

« ♦

A. F L A V 1 P E S

FUMIGANT

1“~ 0

-214-

-215-

Table 3.7 The percentage mortalities of A . ^ l a v i , p o . 6 larvae exposed to the fumigant activity of residual deposits of insecticides in wooden boxes for 48 hours.

♦ IF

Insecticide Cone.

(mg/box)

0 1 2 4 5 6 8 9Age10

of12

deposit 13 15 16 17

(weeks) 19 20 21 23 24 25 26 28 29 32 33 37

CHLORPYRIFOS- 1 93 58 70 70 13 13 38 8 48 13METHYL 2 100 78 100 85 53 38 53 48 65 4510 100 78 98 98 65 80 75 68 60 550 0 0 0 0 0 0 0 3 3 0RELDAN 1 93 70 73 60 35 10 8 10 35055 e.c. 2 95 83 75 73 58 40 30 35 2810 100 93 95 95 70 68 45 53 500 0 0 0 0 0 0 0 0 0PIRIMIPHOS- 1 28 35 35 25 13 18 8 8 0METHYL 2 33 30 30 40 20 25 33 20 810 50 45 45 48 45 55 35 38 180 0 0 0 5 0 0 0 0 0LINDANE 1 100 100 93 45 18 18 5 5 5 3 32 100 100 100 90 45 43 40 28 20 33 2310 100 100 100 98 95 90 90 80 80 75 500 0 0 3 0 0 0 0 3 3 0 0EMPENTHRIN 1 10 25 10 15 5 0 02 18 63 20 30 23 5 010 38 85 53 75 50 15 00 0 0 0 0 0 0 0DIAZINON 1 40 75 50 68 55 33 13 02 50 78 63 68 60 50 18 810 58 75 83 75 75 53 30 180 0 0 0 0 0 0 0 0DICHLORVOS 1 100 88 53 5 02 100 93 75 18 510 100 100 95 58 100 0 0 0 0 0

NAPHTHALENE 1300 68 60 50 43 25 8 13 0 0 0 0 0 02600 80 78 70 68 70 80 75 78 33 28 0 0 05200 85 80 73 88 75 73 78 83 73 70 50 55 00 0 0 0 0 0 0 0 0 0 0 0 0 0PARADICHLOR- 1300 100 0 0 0OBENZENE 2600 100 100 10 05200 100 100 100 00 0 0 0 0

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-217-

Table 3.8 The percentage mortalities of A . ^ t a v J L p o ^ larvae held in fly puparia and exposed to the fumigant activity of residual deposits of insecticides in wooden boxes for 48 hours.

#

♦

♦

Insecticide Cone.

(mg/box)

0 1 2 3 4 5 6 8 9Age10

of deposit 12 13 15 16 17

(weeks) 19 20 21 23 25 26 28 32 33

CHLORPYRIFOS- 1 63 33 13 5 0 0 0 1 0 0METHYL 2 71 41 19 6 0 1 3 4 1 0

10 73 45 56 76 56 68 53 40 29 230 0 2 0 0 2 3 0 0 0 0

PIRIMIPHOS- 1 1 11 5 4 6 0 0 0METHYL 2 4 20 9 6 4 0 0 0

10 5 25 13 19 11 8 3 00 0 0 3 0 0 0 0 0

LINDANE 1 25 14 11 8 3 1 0 0 02 56 68 30 16 5 4 3 0 010 69 60 83 79 78 73 83 52 150 0 0 0 0 0 0 0 0 0EMPENTHRIN 1 34 26 14 1 0 0 02 28 51 31 9 0 0 010 33 69 49 28 8 0 00 0 0 0 0 0 0 0DIAZINON 1 45 80 29 20 9 0 0 02 50 98 35 26 20 1 4 010 65 93 53 44 28 14 8 00 0 0 0 0 0 2 0 0DICHLORVOS 1 100 63 39 0 02 95 75 60 4 010 100 78 75 30 00 0 0 0 0 0

NAPHTHALENE 1300 3 5 6 4 5 9 0 0 0 02600 10 8 11 13 8 15 13 3 0 05200 18 24 20 26 24 20 19 13 8 00 0 0 0 0 0 0 0 0 0 0PARADICHLOR- 1300 64 0 0 0

OBENZENE 2600 78 61 0 05200 98 95 66 00 0 0 0 0

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-219-

deposits aged the fumigant toxicity generally became less active. Enclosing the test insects in insect cuticle usually resulted in a significant reduction in mortality. LC^q and 95% confidence limits were calculated for each assay period and these values are tabulated in Tables 3.9 and 3.10. LC^q's are expressed in terms of the quantity of active ingredient required to kill 50% of the test insects when applied to filter paper placed in the wooden test boxes. The relationships between LC^/log LC^q to time after treatment were explored as described in Section 3.3.1. No significant straight line relationships could be derived in most instances. Where a relationship was apparent decay was kinetically first order with respect to the loss of activity, except for naphthalene which approximated to a zero order rate (Table 3.11). The apparent lack of correlation in the majority of cases probably arose because probit regressions were based on 3 concentrations only and therefore even small changes in mortality could result in large changes in the estimated LC^q. Insufficient data were available to determine if there was a relationship between insecticide vapour pressure and rate loss of activity under the test conditions.

On the basis of the percentage mortality data (Tables 3.7 and 3.8), lindane, chlorpyrifos-methyl, pirimiphos-methyl and diazinon where the most effective insecticides tested in terms of their persistence as vapour toxicants in wooden boxes. Naphthalene and PDB were the least effective and extremely high application rates were required to obtain the desired residual activity. The rapid decay of PDB may in part have been due to the nature of the solid phase used in the tests. Had large crystals or blocks of PDB been used instead of fine crystals, then volatilisation may have taken place more slowly.

3.3.5 Field evaluation of some candidate compounds (i) Lindane

No infestations have been reported 8 months after treatment in either the treated or control drawers. As the control drawers were unaffected during the trial and incidences of larval infestation throughout the Entomology Building were low during this period, no conclusive results can be drawn from this trial.

»

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A g e o f d e p o s i L ( w e e k s )1 nst;c Ti c i de 0 1 2 A 5 6 0 9 10 1 1 12 13 15 16 17 19 20 21 23 24 25 26 28 29 32 33

C H L O R P Y R I F O S - ( 0 . 7 0 ) ( 0 . 9 0 ) ( 1 .05) (0.50) (7.61) (5.16) (9.15) (3.60) (13.5)M E T H Y L 0 . 2 3 0 . 4 2 0.51 4 .32 3 . 0 6 2 .19 4 . 6 2 0 . 4 5 6 . 6 9

( 0 . 0 6 ) ( 0 . 2 0 ) (0.24) (2.10) (2.10) (0.93) (2.34) (0.0 6 ) (3.33)R E L D A N (0.44) ( 0 . 6 3 ) ( 0 . 0 1 ) ( 1.56) (4.50) (9.06) (20.0) (17.1) (19 . 7 )5 0 % o.c. o. 1 2 0 . 2 7 0 . 3 0 0 . 7 0 2.25 4 . 9 0 9 . 9 5 0.5 4 9 . 9 0

(0.03) ( 0 . 1 1 ) ( 0 . 17) (0.39) (1.11) (2.52) (4.94) (4.25) (4.95)P 1 R 1M 1 PI 105- (25.4) ( 2'10) (77.0) (20.4) (31.1) (17.0) (64.2) (46 . 4 ) (150)ME UlYL 11.6 3 7 . 3 23.1 12.3 1 5.0 0.01 27.3 2 1 . 0 6 4 . 7

(5.24) (5.01) (6.93) (5.34) (7.23) (4.37) (11.7) (10 . 2 ) (26.7)L 1N D A H E (2.07) (5.04) (5.66) (6.50) (9.21) (10.0) (9.00)

1 .05 2.5 7 2 . 0 0 3 . 3 0 4 . 6 0 5 . 0 9 4 . 9 0(0.53) (1.31) (1 .46) (1.60) (2.33) (2.50) (2.52)

EMPF.N TURIN ( 5 Z . 7) (2.72) (20.1) (9.0 0 ) (17.5) (100)24.2 2.15 10.0 4 . 5 6 8.04 72.2

(11.1) (0.69) (5.01) (2.31) (4.44) (29.1)D I A Z I M O M (12.0) (2.21 ) ( 2 5 1 ) ( 1 . 6 5 ) (13.3) ( 276) (157)

6 . 0 0 1 .00 0 . 0 2 0 . 7 2 6 .02 7 0 . 0 6 4 . 7(2.01) (0.53) ( - )(0.32) (2.73) (22.5) (26.7)

mClII.ORVOS (0.57) (1 . 9 1 ) 0 7 . 1 ) (1005)0.2-1 0 . 9 6 0 . 6 0 210

( 0 . 0 0 ) ( 0 . ' 1 0 ) 0 . 0 ) (47.3)N A P H T H A L E N E ( 1 1 7 9 ) ( 1 6 1 7 ) ( 2 6 3 4 ) ( 3 6 2 9 ) (4074) (5562) (5300) (5673) (0220) (0667)

'100 732 1201 1041 2 4 7 0 2031 2 700 2092 4 1 0 7 4 4 1 6( 201)( 333)( 621 )( 935 ) (1260) (1442) (1374) (1473) (2135) (2250)

Table 3.9 l.is Limn Led LC^q vaj.ues (mg/box) for A . falavipPA larvae exposed Lo Lhe fumiganL acLiviLy of residual deposiLs of insecLicides in wooden boxes. 95X confidence lim.i.Ls are in parenLheses.

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♦

Age of deposit (weeks)1nsec+icide 0 1 2 4 5 6 8 9 10 11 12 13 15 16 17 19 20 21 23 25 26CHLORPYRIFOS- (0.99) (81.9) (17.6) (1 2 .6) (17.0) (2 1 .2 ) (29.7)METHYL 0.09 25.1 8.91 6.39 8.60 1 0 . 8 15.0

(0 .0 2) (7.65) (4.50) (3.26) (4.38) (5.46) (7.61)PIRIMIPHOS- (1457) ( - ) (267) ( - )METHYL 275 4266 109 10658

(51.8) (33.8) (44.4) (8.31)LINDANE (6.0 2) (7.37) (8 .0 1 ) (12.9) (14.5) (13.2) (20.7)

3.05 3.72 4.07 6.54 7.38 6.71 1 0 . 6(1.55) (1 .88) (2.07) (3.33) (3.77) (3.42) (5.39)

EMPENTHRIN (6.47) (21.9) (60.5)3.27 1 1 . 0 29.7(1.67) (5.45) (14.7)

DIAZINON (4.23) (18.5) (40.5)(218) (93.6) (1641)2.09 9.00 19.1 83.4 44.9 390(1.04) (4.41) )9.00)02.1) (21.5) (93.3)

DICHL0RV0S (0.42) (0.44) (40.2)0 . 1 1 0.06 (20.a)(0.03) (0 .0 2)

NAPHTHALENE (46922)(35372)(74990)(26067) (35868) (177296) (28433) (28991)22200 17220 32310 12968 17220 57555 14132 14366(10491)( 8385)(13905)( 6458) ( 8501) (18684) ( 7020) ( 7112)

Table 3.10 Estimated LC^q values (mg/box) for A.l l a v X , p d 6 larvae held in fly puparia and exposed to the fumigantactivity of residual deposits of insecticides in wooden boxes. 95% confidence limits are in parentheses.

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i nsecticideAssay

conditionKinetic rate

orderEstimated rate loss (mg/box/wk)

Correlation coeff. (r) & significance

NAPHTHALENE vial zero 134.3 0.955 ***DICHL0RV0S vial 1 st. 26.48 0.997 ***DIAZIN0N pupari a 1 st. 8.77 0.946 **RELDAN 50% vial 1 st. 0.65 0.962 ***LINDANE vial 1 st. 0.18 0.941 ***

pupari a 1 st. 0.23 0.960 ***

Key ** significant at p ^ 0.01, *** significant at p ^ 0.001.

Table 3.11 Estimated rates of loss of insecticidal activity in wooden boxes at 25°C based on significant straight line relationships between fumigant LC q and time after treatment.

*

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(ii) Chlorpyrifos-methyl

No infestations have been reported in treated drawers at the BM(NH)6-7 months after treatment. Complaints were received however regarding the odour of this insecticide formulation when used in insect drawers. Chlorpyrifos-methyl has a pungent captan smell characteristic of organophosphorous compounds. Treating filter paper strips proved to be very labour intensive and it was considered that any long term usage of this method of application would require the work to be carried out under contract.

In the assay conducted in the laboratory 100% mortality was observed within 5 days in early instar A. a n .y iic .u .6 larvae introduced at the time of treating the boxes and 10 weeks after treatment. No larval damage to the museum specimens was noted. When an infestation was established introduction of impregnated strips 10 weeks later was not so effective. 14 days after treatment approximately 30% of larvae were still alive and feeding on the specimens. 28 days after treatment however, all larvae were dead.

No adverse effects from the fumigant phase of chlorpyrifos-methyl were observed to the colours of butterfly specimens, card, paper and Plastazote, either at high or low humidity. Corrosion of plated brass and lacquered brass pins however was observed at high humidity, although not in the controls. Stainless steel pins were unaffected.

(iii) Empenthrin

The percentage mortalities of early instar A . f i lc iv jL p z A larvae to the fumigant activity of aging Vaporthrin mothproofing strips in insect storage boxes are illustrated in Table 3.12a. In Table 3.12b antifeedancy effects of aging deposits are assessed qualitatively based on the extent of feeding damage to woollen material compared to the untreated controls. High concentrations of empenthrin (125-250 mg/ box), were effective in controlling larvae for at least 7 months at 25°C. Mortality effects were relatively slow acting but antifeedancy was apparent at high concentrations after only 48 hours exposure.

♦

#

Deposit(mg/box)

48 hour Exposure time 5 days0 1 2 4 8 12

weeks after t 16 20 24 28

'eatment 0 1 2 4 8 12 16 20 24 28

65 0 63 55 43 30 18 0 0 - - 85 78 83 75 80 68 48 23 0 0

125 0 55 70 58 60 53 48 35 23 0 100 95 100 98 93 100 88 80 60 70250 10 85 83 75 80 63 78 50 55 50 100 100 100 100 100 98 100 93 88 85

0 0 0 5 0 3 0 0 0 0 0 0 0 0 3 3 0 5 0 3 0

65 + + + + iiii++

125 iii+i++++i + + + + + + + + i i

250 + + + + + + + + + + + + + + + + + + + +

0

(a).

(b).

Key + = feeding inhibition on woollen cloth observed, - = feeding inhibition not observed.

Table 3.12 Effects of the fumigant activity of aging Vaporthrin mothproofing strips to early instar A . f i l a v l p o . * larvae in insect storage boxes, (a) % mortality, (b) antifeedancy.

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3.4 Discussion

Barlow & Hadaway (1968) determined that evaporation of insecticides from inert surfaces approximated to zero order kinetics. Similarly Carter & Chadwick (1978) found that several pyrethroids, organo- phosphates and lindane on plywood exhibited a zero order rate loss of biological activity. Desmarchelier (1978) however, showed that loss of insecticidal activity on wheat followed first order kinetics and Barlow o X a t (1977) found that deposits of pyrethroids on mud approximated to a first order loss of activity. In the present study the kinetics of loss of activity differed between insecticides and surfaces to which the residual deposits were applied. Clearly, even though loss of activity can often be approximated to a zero or first order rate law, the individual processes involved such as evaporation, diffusion, sequestering and photodegradation, may follow different kinetics.

Regression analysis of vapour pressure against rate loss of insecticidal activity has shown that the residual life of insecticides as fumigants and contact toxicants can to some extent be predicted from their vapour pressures. Correlations for loss of activity from glass surfaces showed greater significance than from filter paper surfaces which was considered to be due to the nature of the treated surface. Glass being inert, does not react or combine with the applied insecticide, filter paper on the other hand may chemically combine with or in some way physically retain (e.g. adsorption) the insecticide rendering it unavailable as a contact or fumigant toxicant. When one is comparing the physical properties of insecticides, as in these experiments, the use of glass surfaces for bioassay may be preferable to more complex substrates because of the likelihood of insecticide-substrate interactions. As an example, the activity of azamethiphos on filter paper declined much more rapidly than when applied to glass. This was surprising because this insecticide has a low vapour pressure and therefore the decline in activity could not be attributed to evaporation, and as both treatments were maintained under the same conditions, photodegradation was unlikely. It seems probable that the insecticide was sequestered by the filter paper in such a way that pick-up by the test insects crawling on the paper surface was reduced. This may be a feature of the technical

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Regression analysis relating apparent LCe-q to age of deposit provides a useful method of considering residual film degradation. The simpler and more frequently adopted method of quoting the period during which an insecticide deposit maintains 100% kill of the test insects, is easier to compute, but provides little information on decline of activity.

Carter & Chadwick (1978) determined the rate losses of diazinon, lindane and iodophenphos on plywood as 444, 336, and 269 mg/m2/week respectively. These values are considerably higher than those recorded in the present investigation. The differences can probably be attributed in part to the more absorbent plywood surfaces to which their deposits were applied and to the test conditions. In addition confining deposits in glass vials may have decreased air exchange, and Phillips (1971) showed that increased ventilation greatly accelerated loss of dieldrin and aldrin from glass surfaces. Tsuda o X a t (1983) determined by gas-chromatography the evaporation rate of empenthrin from glass at 25°C as 1330 mg/m2/week. The rate loss of biological efficacy in the present study was lower for loss of both fumigant and contact activity.

There is no published data available to compare the LC__ and LCQt- estimates obtained in this study for the range of insecticides assayed against A n t h t i z n u A species. In retrospect it may have been more appropriate to have applied deposits to filter papers rather than glass, as the former method is the one most widely used for testing film deposits against stored products insects (Pinniger,1983). LC^q estimates were generally lower than those recorded for other stored products insects assayed on filter paper, probably because the impermeability of glass surfaces allowed easier pickup of insecticide by the test insects. For example, Tsuda o X a t

(1983) recorded the LC^q of empenthrin and dichlorvos to T t n z a

p e X t t o m t t a larvae by contact with treated wool cloth for 48 hours as 54.9 and 86.8 mg/m2 respectively. The equivalent contact toxicities to late instar larvae of A.-6a n n tc .u .& in the present study

material only however, as wettable powder formulations of azamethiphoshave a rapid knockdown effect and good residual activity on a rangeof surfaces (Worthing & Walker, 1983).

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were 0.70 and 0.25 mg/m2 for a 24 hour exposure period. Also when test insects were exposed to residual films in glass vials, fumigant activity of the insecticides contributed significantly to mortality. In the more usual tests of contact activity where insects are confined on filter papers inopen glass rings for example, fumigant effects of sufficiently volatile insecticides will be markedly reduced by air exchange.

The effectiveness of insecticides were compared on the basis of potency, and in fact for valid comparisons to be made the concentration-mortality regression lines should be parallel; otherwise the relative potency varies with the mortality level chosen and if the curves cross, one insecticide will actually be more toxic above the intersection level and less toxic below it.Because of the large numbers of regression lines being compared and the different chemical groups to which the insecticides belong, parallelism was unlikely, therefore potencies are generally given relative to both the LC^q and LC^ values, resulting in consequent differences in the order of potency. Potencies should therefore not be considered as precise values but only as a rough guide to the performance of the test insecticides relative to each other, and against the different developmental stages of the three A Y L th tizm iA species.

Parkin & Woodroffe (1961) reported that insecticides were more effective at killing adult beetles and newly hatched larvae than the other stages of A .\)Q Jib c L 6 c .JL. This is consistent with the results of the present study. Older larvae may be more tolerant as are

♦ many insect species, but an additional feature which may have influenced these results was the onset of diapause in some larvae which is known to increase the tolerance of many stored products insects to fumigant and contact insecticides (Bell, 1982).

The tests undertaken in wooden boxes with insecticides exhibiting fumigant activity have demonstrated that there are a number of candidate compounds that would be effective in controlling K n t k f i < i n a 6

in closed airspaces of relatively small volume. The principal criteria for an insecticide to be of potential use in the museum environment are: (1) long residual life, (2) high potency to

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target pests by fumigant activity in particular, and (3) low application rates of active ingredient. From a consideration of the results presented for decay of activity (Table 3.2) and LC^q estimates (Appendix V), the initial dose required to kill 50% of the target species under the test conditions after a defined period can be estimated. Using the example of Carter & Chadwick (1978), if the LCj-q for species A is 50 mg/m2 and for B 100 mg/m2 , and the decay rate is 10 mg/m2/week, 100 mg/m2 will have to be applied initially to kill 50% of A in tests after 5 weeks, while 150 mg/m2 will be required for B. Table 3.13 shows the deposits in glass vials required to kill 50% of early instar A. 6cin.YiJic.uL6 larvae by fumigant and contact activity under the test conditions after 4 months. The insecticides are ranked in order of increasing initial application rate, i.e., the lower the rank number the better the insecticide fits the required criteria. PDB and naphthalene were the least effective because of their low persistence and potencies, while insecticides with vapour pressures in the range 1-150 mPa at 20°C possessed the most persistent fumigant effect.

Tannert (1960) found that filter paper strips impregnated with lOOmg of lindane were effective in controlling in museum drawers for 1-2 years, although the onset of mortality was delayed by the slow action of this compound, which was true particularly for the late instar larvae. Under similar conditions Spencer (1963) found that Igm of lindane crystals sprinkled on the floor of insect drawers controlled dermestid larvae for at least one year. Laudani (1959) reported that lindane crystals applied at a rate of 176 gm/m3 protected boxed woollens against At t a .g e .n u .6 (Oliv.) and

* A . { ,Z a .v X ,p e .6 for 3 years or longer. Young A .4 a> iy u L c .u .4 larvae were ofcomparable susceptibility to vapour phase lindane as A. therefore the concentrations used are likely to be effective in controlling this species also. Late instar A . a c l m J j l u . * larvae however were approximately two times less susceptible than the younger instar, similar to the differences observed by Tannert (1960) for A .v e J i b a 4 c . J L . In the present study lindane proved to be the most effective insecticide tested, but in some instances might be less acceptable given that it has a relatively high mammalian toxicity. Chlorpyrifos-methyl with its considerably lower mammalian toxicity would be more acceptable for use in buildings where staff are

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1nsecti c i deDeposit

FUMIGANT(mg/m2)

CONTACT

PARADICHLOROBENZENE 4.76 x 105 (8) 3.84 x 105 (11)NAPHTHALENE 2.56 x 105 (7) 1.57 x 105 (10)DICHLORVOS 8.35 x 104 (6) 4.42 x 103 (9)EMPENTHRIN 4.35 x 103 (5) 3.88 x 101 (4)DIAZINON 2.53 x 103 (4) 3.68 x 103 (8)P1R1M1PHOS-METHYL 2.14 x 102 (2) 1.76 x 101 (3)CHLORPYR1FOS-METHYL 2.74 x 102 (3) 9.92 x 101 (6)LINDANE 10D0PHENPH0S CYPERMETHRIN FMC 54800

1.47 x 102 (1) 5.89 x 102 (7) 4.16 x 101 (5) 2.42 x 10"1 (1) 9.60 (2)

Table 3.13 Initial deposits in glass vials required to kill 50% of early instar A . 6 a ^ i y i i c u 6 larvae by fumigant and contact action after 4 months, based on 24 hour exposure at 25°C. Figures in parentheses are the ranks of effectiveness.

*

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exposed to the fumigant vapour for much of the working day. The major drawback of using chlorpyrifos-methyl or its formulated products is the odour which could prove unacceptable if used on a large scale in relatively unventilated rooms. Late instar larvae of A.4a t i t v i c u . * were considerably more tolerant than young larvae to vapour phase chlorpyrifos-methyl and this is probably the reason why in insect storage boxes the compound was slow acting against this stage. Pirimiphos- methyl and diazinon were less effective, but the odour of these formulated products might be more acceptable, though this aspect was not tested.

The fumigant pyrethroid empenthrin proved to be of low insecticidal potency to A n th .t ie .n u 6 species, but has the advantage over most of the other insecticides tested in that a suitable formulation for use in museums is commercially available and it is virtually odourless. Impregnated filter paper strips containing 500mg of empenthrin are marketed as 'Vaporthrin mothproofing strips' (Sumitomo Chemical Co.). Yoshida e t a t (1983) showed that papers containing 500mg of empenthrin in a wardrobe of volume 0.7m3 containing clothes, provided effective control against T t n e . a p e Z L L o n e t l a . larvae for at least 12 weeks, and 2000mg for over 24 weeks. Sublethal concentrations of this compound inhibited feeding in T . p e t l t o n e t l a (Tsuda e t a t . , 1983), a feature common among the pyrethroids, though this was not seen in the A.4amccu.4 studies except at concentrations which over long exposure periods eventually resulted in mortality. The quantity of empenthrin required to give effective control for 24 weeks in museum insect boxes was ten times higher per unit volume than it was for T . p e t l t o n e t l a in wardrobes. The fumigant activity was 100 times less potent to late instar larvae of A . 6 a s i n t c . u 6 , therefore concentrations which could realistically be maintained in museum situations would not be effective in controlling this stage. The fumigant pyrethroid FMC 54800 also tested proved to be of low potency as a fumigant against k n t h .t i e x iu 6

but was extremely active as a contact toxicant - in terms of potency being second only to cypermethrin.

Empenthrin remains stable at high temperatures (Sumitomo technical report), and no adverse effects have been reported after extensive tests on fabrics. Because of its low mammalian toxicity, high app-

#

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lication rates (28 gm/m3), can be used to obtain the desired residual activity. Recent developments in the synthesis of pyrethroids have produced several compounds with relatively high vapour pressures. Fenfluthrin for example is reported as having a fast knockdown action as a fumigant, good residual properties and high potency to fabric and stored-product pests (Behrenz & Naumann, 1982). As these compounds tend to be virtually odourless, relatively stable and of low mammalian toxicity, they should be screened for use in museums, certainly if empenthrin is cleared for use in the U.K. further field evaluation in museums would be worthwhile.

The fact that persistence can be increased by suitable formulation is clearly demonstrated by dichlorvos. High concentrations of dichlorvos on filter paper in wooden boxes lost their biological activity after 6 weeks. On the other hand dichlorvos impregnated into PVC (e.g. 'Vap- ona strip'), evaporates slowly over a number of months. Scudamore o X a t (1980) found that use of dichlorvos slow-release units at between 1 & 6 times the recommended rate for normal domestic or industrial use in museum display cases and cabinets protected specimens from pest attack for periods of 6 months or more. Ryckman (1969) found that 4.5 x 6.3 cm pieces of Vapona strip in wooden insect boxes provided protection against dermestid larvae for up to 2 years. However, despite its effectiveness, dichlorvos is not an ideal pesticide for use in museums because of its relatively high mammalian toxicity, odour, corrosive properties to iron and mild steel, and its potential for staining and discolouring specimens (Stanley & McCann, 1981). It seems probable, although further tests would be required, that persistence of fumigant activity of insecticides of

• lower vapour pressure is not likely to be enhanced by formulation tosuch an extent as the high vapour\insecticides such as dichlorvos, without reducing the rate of evaporation to such an extent that insufficient of the vapour phase is present to produce a toxic dose.

The results of the present study have shown that naphthalene is insecticidal by vapour action to k n th .n .n y iu .6 species, albeit at very high concentrations. A . 6an.njL(LUL6 early instar larvae are slightly more tolerant to naphthalene than k . ^ l a . v J i p 2A larvae used in the box assays. The potency to late instar larvae is some 20 times less than to early instars. This may in part explain why some workers consider

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naphthalene to be ineffective. Herrick & Griswold (1933) found that large larvae of k .vo .tib oL t> c .jL were resistant to the vapour effect of naphthalene sprinkled at a rate of 1.6 Kg/m3 in boxes containing clothing even after 21 days exposure. They comment however that larvae were affected by the treatment and feeding was inhibited. The results from this thesis have shown that late instar A. l a v i , p o , 6 larvae are almost 10 times more tolerant to naphthalene than the equivalent stages of A . 60Ln.njLc.a6 . PDB was less persistent than naphthalene, probably caused by virtue of its high rate of evaporation and loss, although it was more potent as a fumigant. Herrick (1931) determined that PDB sprinkled at a rate of 160 gm/m3 in fairly airtight boxes containing clothing was sufficient to kill T l - m o l a b jL 66Q JL& L zJU La. Hum., larvae over a period of at least 3 months. PDB, once the mainstay for prophylactic treatment of museum cases is used less frequently now because of potential health risks (liver cirhosis and kidney failure in particular), and because it softens and melts certain plastics, which are increasingly being used in cabinet construction and display of specimens. Chlorine gas may be formed in closed containers also (Stanley & McCann, 1981), resulting in bleaching of specimens.

Bottimor (1929), Billings (1934) and Abbott & Billings (1935) considered that both naphthalene and PDB were ineffective as repellents against clothes moths, but did not determine their efficacy in terms of mortality in sealed containers. Because of their low potency, for either naphthalene or PDB to be effective box lids need to be well fitting in order to maintain adequate vapour phase concentrations.As determined in the olfactometer experiments, sublethal concentrations

• may have a repellent effect, although this has not been demonstratedunder conditions experienced in the museum environment. The principle advantages of naphthalene and PDB are that they are relatively cheap, supplied in a solid form which is easy to handle and dispense, and rapid visual inspection of the quantity of crystals remaining determines when replenishment is required.

It was encouraging to note that all the insecticides tested were capable of penetrating insect specimens (fly puparia), by vapour action, and killing the pest insects feeding within. Mortalities were generally lower than their counterparts for larvae exposed in glass tubes, but

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extended exposure periods rather than the 48 hours used in the tests should result in the pests acquiring a lethal dose. Whether insecticides would be able to penetrate the.bodies of large bodied specimens where the dried tissues and lipids in particular would be likely to provide a considerable sink for insecticides, is more doubtful. A toxic dose may however be picked up by contact or ingestion of insecticide absorbed by the specimens. The fact that the specimens to be protected and the other contents of museum cases will absorb insecticide from the airspace should be taken into consideration and may increase the application rate required per unit volume to be treated. If too little active ingredient is used specimens may absorb a large proportion from the vapour phase such that insufficient is present in the atmosphere for pests to acquire a toxic dose. Sufficient active ingredient must be present to maintain sufficient in the vapour phase to achieve the desired toxicity to invading pests. In this way a dynamic system can be envisaged with the specimens themselves acting as slow release units releasing sorbed insecticide as the vapour phase concentration declines, thereby increasing the effective life of a treatment.Tsuda z X a . t (1983) for example, found that empenthrin showed longer lasting biological activity in a wooden box containing woollen material than was predicted from chemical assay. It was considered that the insecticide evaporating from the carrier filter paper was partly absorbed by the walls and materials in the box and released once the quantity of active ingredient on the carrier had declined to a level such that equilibrium could no longer be maintained. Scudamore z X a t (1980) found that dichlorvos slow-release units used in museum cases showed considerable residual vapour

« concentrations, probably due to vapour diffusing out of mountedspecimens, paintwork and other materials in the cases. In practical terms where the enclosed volume may contain a large area of absorbing surfaces, this would require applying a high initial dose to saturate the 'sinks' and reach equilibrium conditions. Providing reapplication was carried out at regular, predetermined intervals, subsequent doses could be lower to maintain toxicity.

The major factor influencing the residual life of a treatment in fairly airtight containers (apart from physical factors such as temperature fluctuation), will be the opening of cases for examin

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ation of the specimens within. In the wooden box assay tests conducted in this study, boxes were kept closed except for the brief intervals when assay materials were introduced and removed. In practice lids of drawers and boxes are often left open for extended periods while the material is examined resulting in the loss of the vapour component irrespective of the vapour pressure of the insecticide. When the containers are closed again the time taken to regain equilibrium concentrations will depend upon the rate of evaporation and quantity of active ingredient available for desorption. Insecticides with low vapour pressure will tend to perform better under such conditions because the rate loss of active ingredient by evaporation from the formulation and 'sinks' will be slower. In fact the opening of drawers and boxes may not be as big a problem as would at first seem to be the case, by virtue of the nature of An t k ^ z n u 6 infestations. The most severe damage to specimens generally occurs in parts of the collection which are examined infrequently and hence containers rarely opened. Parts of the collection used regularly for reference are less susceptible to severe damage because of frequent disturbance and the identification of pest attack at an early stage before widespread damage has occurred.

It has already been pointed out that many insecticides or their degradation products may damage the artefacts they are used to protect. In this thesis it has been shown that at high temperature and humidity treatments of chlorpyrifos-methyl may lead to corrosion of entomological pins. The decomposition products of Reldan 50% e.c., under heat plus air are SO2, HC1 and organic sulphur compounds (Dow technical report). Under normal museum conditions of moderate temperature (20-30°C) and low humidity, such decomposition is unlikely to occur, although as with most insecticides it should be realised that there is always the potential for such damage. There are no hard and fast rules that can be laid down regarding the reactivity of the different groups of insecticides to materials, therefore the effects of every candidate compound should be evaluated in relation to the specimens and artefacts they are required to protect.

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An important consideration when selecting an insecticide for use in museums are the potential health hazards, particularly in relation to exposure to airborne toxicants which are inherently more difficult to control than for example hazards derived from skin contact.Section 2 of the Health & Safety at Work Act 1974, places upon employers a legal obligation to ensure, so far as is reasonably practicable, the health, safety and welfare at work of all their employees. The limits to which exposure to airborne substances hazardous to health (including some pesticides), should be controlled in workplaces are outlined in the Health & Safety Executive (HSE) guidance note EH40(1984).

Naphthalene has long been considered to be safe to use in museums, a conception which seems to have been derived from traditional use rather than scientifically based data. The results from the present study have shown that the ’newer’ insecticides can be used at greatly reduced concentrations to achieve more effective control. If one compares naphthalene with lindane for example, the HSE limits for long term exposure are 50 & 0.5 mg/m3 respectively. Based on this information alone naphthalene would appear to be safer because the acceptable exposure level is 100 times greater than for lindane. However, the application rate of naphthalene required to give less effective control of pests in museum containers is over 500 times greater. In addition the evaporation rate of naphthalene is around 900 times faster than lindane, therefore the rate of diffusion of naphthalene vapour into the working environment could be expected to be substantially greater. Chlorpyrifos-methyl is considerably less toxic to mammals based on dermal and acute oral toxicity tests,

* than lindane, and of comparable toxicity to naphthalene. Vapourphase exposure limits have not been set to date, but are likely to be higher than lindane. Obviously this example gives only a crude idea of the merits based on safety of using low vapour pressure insecticides in storage cases. Extensive use of any chemical in a workplace which is likely to cause contamination of the working environment should be monitored and airborne concentrations maintained as low as is practicably possible.

A specific problem which needs to be investigated is the atmospheric concentrations of insecticide that workers are exposed to immediately

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upon opening an insect drawer. If there is an excess of the solid phase in an airtight container, vapour concentrations may approach the saturation concentration. Opening drawers without adequate ventilation could result in workers being exposed to concentrations above the short term exposure limit recommended by the HSE. Assuming that insecticides follow the perfect gas law, the saturation concentration at a specific temperature can be calculated thus:

P „ 273 „ M „ „n3760 x T " x 2274 x 1 x 10

where: C = saturation concentration (mg/m3)P = vapour pressure (mmHg)M = molecular weight (gm)T = absolute temperature (K)

At 20°C saturation concentration values for naphthalene, dichlorvos, diazinon and lindane are: 348, 145, 2.3 & 0.2 mg/m3 respectively.The corresponding recommended short-term exposure limits based on a 10 minute time weighted average are 75, 3, 0.3 & 1.5 mg/m3 respectively (HSE Guidance note EH40). In practice the saturation concentration is seldom attained because of leakage and absorption, but the values quoted above show that boxes containing naphthalene, dichlorvos and diazinon, could potentially result in workers being exposed to airborne concentrations above the recommended limits

ofparticularly where large numbers\treated specimen boxes are opened during the working day. It is interesting to note that the concentration of lindane, because of its low vapour pressure, does not approach the exposure limit.

Overall, the present investigation has demonstrated that many insecticides are sufficiently volatile to exert a toxic vapour effect in small enclosed volumes, and therefore have potential for use in museum pest control situations. Guidelines have been established for further research and whether or not new methods of insecticidal control are introduced will depend upon the level of commitment to further research and development by the museum fraternity. Further work is particularly needed on the determination of vapour phase concentrations inside sealed boxes and in the working

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environment in order to determine the likelihood of a toxic inhalation hazard. Such a study would require long term field evaluation of candidate compounds in conjunction with further appraisal of formulation and application techniques.

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3.5 Summary

A range of insecticides were bioassayed for efficacy for use in museum situations and the results compared with traditionally used pesticides. The aims were to provide baseline data on the fumigant and contact toxicities of the selected insecticides to knthn.z.vni6 pests, and to determine the persistence of fumigant active insecticides under museum storage conditions.

1. Persistence of the fumigant and contact activities of a range of insecticides selected on the basis of low mammalian toxicity and vapour pressure to cover the vapour pressure range from highly volatile (paradichlorobenzene) to virtually non-volatile (cypermethrin), were tested using a glass vial bioassay technique. From regression analysis it was demonstrated that the residual life of insecticides as fumigants and contact toxicants applied to glass, filter paper and 'Plastazote' surfaces could more or less be predicted from their vapour pressures. Decay of insecticidal activity could generally be approximated to zero or first order reaction kinetics.

2. The relative susceptibilities of the different developmental stages of A. t>O Ln.Y iLni*, k . ^ IcLvX jpQ ,* and A.veA6a4cL to the contact and fumigant toxicities of the test insecticides were determined. In general the pupal stage was the most tolerant to fumigant toxicity, and late instar larvae were more tolerant than adults and early instar larvae to both fumigant and contact toxicity. The susceptibilities of the same developmental stage of the three species differed relative to

+ each other between insecticides and whether potencies were based onthe L.C. q or L.C.g estimates.

3. Insecticides which were shown to be active as fumigant toxicants were tested in small scale box trials simulating museum insect collection storage conditions. Lindane, chlorpyrifos-methyl, pirimiphos-methyl and diazinon were the most effective in terms of persistence as vapour toxicants. Naphthalene and PDB were the least effective, high application rates being required to achieve the desired residual activity.

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4. Lindane, chlorpyr if os-methyl and empenthrin were tested in museum storage conditions. No infestations were observed in treated insect drawers 7-8 months after application.

5. The relative merits of the different insecticides tested are discussed in relation to persistence, potency, potential hazards to staff and objects to be protected.

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PART IV

STRATEGIES FOR PEST CONTROL IN MUSEUMS

The control methods and recommendations presented below are drawn from the available literature coupled with the research, observations and experiences gained during this study.

4.1 Chemical control

Several of the insecticides tested during the course of this study would be effective as fumigants for the prevention of pest attack in insect collections, and for other specimens and artefacts stored in relatively small enclosed volumes. Table 4.1 summarises the application rates, approximate effective life of treatments and potential effects on specimens for five of the insecticides tested. The application rates quoted are for museum insect drawers of internal volume6 x 10 m3 and have been scaled up on a quantity per unit volume basis from the amounts of active ingredient used in the box bioassay experiments described in Section 3.2.6, and are therefore only very approximate. All of the compounds tested except PDB should provide effective treatment against early instar k n t h ^ m i 6 larvae for at least7 months. As mentioned in Section 3.3.4 the extremely short residual life of PDB was probably due to the nature of the solid phase used in the tests. Clearly in terms of the quantity of active ingredient required, naphthalene is of low efficacy compared to chlorpyrifos- methyl, lindane and empenthrin, but the major problem associated with the use of the 'new' insecticides is that suitable commercial formulations are not generally available for use in museums. In the present study insecticides were applied to filter papers which were subsequently put into insect drawers. Whether museums would be prepared to adopt this method will depend largely upon staffing levels, because the work involved is labour intensive and requires training of personnel in pesticide application and safety procedures. Were there sufficient demand for suitable formulations, then preparations could probably be made under contract. The main reason that naphthalene and PDB are still used is that the crystals are easy to handle and readily applied into insect drawers, display cases and storage cabinets. The same can be said for dichlorvos slow-release

Naphthalene PDB Chlorpyrifos-methyl

Empenthrin LindaneApprox, a.i. used/ insect drawer 30 gm. 30 gm. 60 mg. 250 mg. 60 mg.

Application method 100%crystals 100%crystals

Filter paper Vaporthrin strips

Filter paper

Approx, life of treatment

33 weeks 2 weeks? >32 weeks >28 weeks >37 weeks

Estimate of toxic hazard based on WHO tentative classification

'slight' ’slight’ 'moderate' 'slight' 'high/modera te'

Possible effects on specimens nonerecorded

may bleach & corrode

may cause corrosion at high humidity

nonerecorded

may potentially produce acidic breakdown products but effects unknown

Table 4.1 Summary of application rates, effective life of treatments and hazards for five insecticides tested for the protection of insect collection drawers against damage by early instar A n th .J ie .n u 4 larvae.

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units (e.g. Vapona) which can quite readily be cut into smaller pieces for use in insect and other collections. Indeed a survey of pest control procedures in museums (Bell & Stanley, 1981) revealed that most respondents used PDB, naphthalene and Vapona because of ease of handling, economy did not appear to be of importance in the choice of a particular pesticide. The list of insecticides screened for vapour action in this study is not exhaustive and continued research should be carried out to test further pesticides, particularly in the vapour pressure range 1.3-150 mPa at 20°C for their fumigant effect.

If suitable formulations of the more effective insecticides are not available for use, then naphthalene should continue to be used in the short-term, but for this chemical to be effective as a vapour toxicant it is essential that an excess of the solid phase is always present in boxes. As mature larvae are extremely tolerant to naphthalene vapour it is important to ensure that established infestations are destroyed using more effective chemicals or physical control measures. The use of 'chemical cocktails’, such as the mixture of petroleum spirit, saturated naphthalene and beechwood creosote which is used in some institutions, is not to be recommended. Inhalation and inflammability risks are high and the effects of such mixtures on specimens are not known.

Research is urgently needed into the prevention of pest damage to stuffed animals, skins and artefacts produced from animal products. Vaporific insecticides are less effective in controlling pests in these situations because of the kinds of storage containers used which tend to be of large volume and not airtight. Furthermore the bulk of some specimens is likely to reduce penetration of the vapour phase, resulting in pests being protected from receiving a lethal dose. Many of the procedures adopted for the proofing of fabrics may be applicable and would provide long-term protection against feeding damage. The pyrethroid permethrin would seem particularly promising (e.g. Duffield, 1977), but no studies to date have been undertaken on its use in natural history collections. The commercial organic mothproofing compounds Edolan-U and Eulan-CN have been used in some museums in the United States. These chemicals provide permanent mothproofing activity as stomach poisons and they have a

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repellent effect discouraging larvae from eating treated wool fibres (Busvine, 1966). Bird and mammal skins have been treated successfully, but the compounds must be applied at high temperatures in a water bath, which is not acceptable in some instances (Stanley & McCann,1981). Arevad (1977) found that treating bird skins on the inside only with Eulan was not effective unless combined with treatments to the external surface. Only dieldrin managed to keep skins undamaged when only the inside was treated.

Apart from treating the collection specimens themselves there is a need to use chemical controls in the general museum environment. The extent to which such measures will be required will depend upon the incidence of pests. Laboratory observations of oviposition behaviour of A . 6 a n . r u . c u 6 has shown that females rarely oviposited directly on insect specimens, preferring to oviposit into small cracks, crevices and on fibrous materials. In museums it is likely that most beetles, unless they have direct access to the specimens, oviposit at floor level (apart from flying adults this is where most beetles are found), and it is the very small, active, first instar larvae which find their way into the collection materials. This migration of crawling insects could be greatly reduced with band treatments of suitable insecticides applied to the insides of cabinet plinths and other voids. Insecticidal dusts incorporating a desiccant which would provide some protection even when the insecticidal activity has decayed are preferable. Silica aerogel formulations incorporating synergised pyrethrins such as Drione (FMC Corporation), are particularly suitable for this purpose (Schofield & Crisafulli, 1980), and are of very low mammalian toxicity. The outside bases of cabinet plinths at floor level should be sprayed with a suitable emulsifiable concentrate(e.c.) or wettable powder (w.p.) insecticide formulation.In the tests conducted in the present study, cypermethrin was the most effective contact insecticide against all life stages of A n t h n . m u 6 .

The protection offered by w.p.'s is more persistent than e.c.'s on porous surfaces but may result in a white deposit being left after evaporation of the water diluent (Cornwell, 1976). Treatments such as these could be put out to contract, and providing suitable residual insecticides were used, would only need to be retreated once a year, the optimum time of year being early spring (March-April), before adult beetles emerge and start to oviposit. In this way the insecticide

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Fumigation of building structures may be deemed necessary if the building has become heavily infested and it is necessary to bring about quick and complete control before more long-term control measures are introduced. Some buildings may be difficult to fumigate due to their construction and advice should be sought from experienced fumigation contractors and the Ministry of Agriculture, Fisheries & Food.Methyl bromide is the fumigant usually chosen, although other fumigants may be used on occasion (ADAS pamphlet, 'Control of Insect Pests in Museums'). Fumigation of individual specimens and artefacts may be carried out also,but such work should be conducted by trained personnel. Fumigants commonly used for such purposes in the U.S. are, Dowfume 75 (70% ethylene dichloride, 30% carbon tetrachloride. Dow Chemical Co.), ethylene oxide and methyl bromide. The general principles of fumigation are outlined in the Ministry of Agriculture, Fisheries & Food pamphlet, 'Safe and efficient fumigation practice:The design, construction and operation of fumigation chambers for use at atmospheric pressure'.

4.2 Non-chemical controls

deposits should be sufficiently active to control wandering larvaethroughout the summer.

(i) Raised temperatureSpecimens in relatively small containers, e.g. insect drawers,can be successfully 'sterilised' using temperature treatments. The Entomology Department of the BM(NH) installed a large laboratory oven for this purpose. Heating boxed specimens to 50°C for 24 hours has been found to be effective in killing all stages of pests encountered and no adverse effects have been observed to specimens or boxes, including plastic specimen drawers. In the course of the present study it was determined that 2 hours exposure to 40°C was lethal to all stages of A.6ol>iyiL(hi6. 30 minutes exposure to 43.5°C is lethal to larvae of clothes moths (Tajiq.oIcl spp.), (Busvine, 1966). Owing to the insulating properties of containers the exposure times necessary in practice to reach equilibrium and hence lethal temperatures, will be greater than those necessary to kill the unprotected insects. The use of heat in combination with relatively high humidity has been used at

9

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other institutions to control pest infestations in botanical collections. Generally raised humidity is required in such situations to prevent specimens becoming too brittle.

(ii) Low temperatureFreezing is another technique which is effective in eliminating established infestations. Crisafulli (1980) quotes a number of institutions where deep-freezing at temperatures of -18 to -40°C for 2 days to 1 week using commercial chest freezers was effective in controlling herbarium pests. Deep-freezing of insect cabinet drawers at -20°C for 24 hours is effective in killing all stages of k Y i t h f i d m i ^ . After treatment boxes should be left to warm up to room temperature before opening to avoid condensation on the cold contents.

Temperature treatments are particularly useful for ensuring that new material and loaned specimens are pest free before they are returned to the main collections. Many of the insect pests found during the course of this study were not native to the British Isles and were most likely introduced into the BM(NH) in parcels and specimens arriving from overseas. There are many routes through which pests may infest museums and a recent survey showed that nearly 50% of curators suspected that the most common route of pest introduction was the integration of new but infested specimens into established collections. Of those who suggested that this was a probable avenue for pest entry only about half routinely treated incoming specimens (Bell & Stanley, 1981).

(iii) Modified atmospheresRaised carbon dioxide levels have been used to successfully control stored products pests in grain. Such methods may be of use in destroying infestations in specimens which are too large to heat treat and where fumigation would be impracticable or may damage materials.Methyl bromide for example should not be used on leather and other proteinaceous materials (Stanley & McCann, 1981). Clearly research relevant to museum practices should be carrried out to determine the value of such novel approaches to pest control.

*

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4.3 Specimen storage systems

Specimens housed in poorly constructed, old or damaged container systems are more vulnerable to pest attack, primarily because they allow easier access to pests and possibly to a lesser degree because leakage reduces the effective life of vapour phase action. Emphasis should be placed on improving container systems in all areas of museum collection storage and as it is preferable to prevent pest entry than to control pests once damage has occurred, pest control requirements should be included in the design of new storage systems. For example, racking systems to house insect drawers installed recently in the BM(NH) do not have doors, thereby providing easier access to pests and making it more difficult to contain the diffusion and leakage of volatile compounds into the working environment. Metal carcassed cabinets with magnetic door seals would greatly restrict pest entry and contain vapour toxicants. Carcasses built on a modular design, each housing say 40-80 drawers, could be isolated in the event of a pest attack and disinfested by heat treatment of the drawers and thorough cleaning and insecticide treatment of the carcasses. Such measures would result in rapid effective control before introducing long-term routine control measures.

4.4 Building hygiene

Birds' nests in roof spaces and eaves often prove to be the principle source of infestations of dermestid beetles in buildings (Parkin & Woodroffe, 1961). If these foci are not eliminated there is always the likelihood of diffuse reinfestation from larvae migrating from nests in roof voids and from emerging adult beetles flying in through open windows and other vents. At the BM(NH) nests and guano of the feral pigeon in ventillation grilles and heating towers were found to be harbouring populations of dermestids and other potential museum pests. Birds' nests should be removed and further nest building prevented where possible.

Accumulations of fluff, dust and debris in spaces between floorboards, under cabinet plinths and other dead spaces, provide ideal breeding sites for small populations of dermestid beetles inside buildings. Regular cleaning and insecticidal treatment of inaccessible voids

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should greatly reduce the favourability of such harbourages for build up of pest populations.

Damaged and worthless specimens and artefacts should be removed from the main collection areas and preferably destroyed. Such items tend to be stowed away in odd comers and forgotten. Left undisturbed such material allows a reservoir of pest populations to build up unnoticed before dispersal to other collection areas.

4.5 Building design

Modifications to the design of existing museum buildings and the construction of new buildings should take into consideration the requirements for efficient pest control procedures. It has been demonstrated in this thesis that A n tk > iQ ,n u .6 beetles frequently fly in and out of buildings via open windows during the summer months.This constant reinvasion, of pests should be reduced as far as possible. This could best be achieved by sealing windows and installing air conditioning systems. Added benefits from such action would be that the collections could be maintained at constant temperature, which is good storage practice, and the residual life of insecticide treatments could be predicted more accurately because decay and evaporation of insecticidal activity is largely temperature dependant (Phillips, 1971). Additionally, a forced draft ventilation system would greatly reduce the potential for a build up of concentrations of airborne toxicants, thereby minimising worker exposure.

As far as is practicable the collections should be isolated from staff working areas. Storing collections in relatively air-tight rooms would allow greater flexibility in pest control procedures. Fumigation could be carried out more easily and hazards to staff from airborne insecticides would be reduced because direct exposure would only occur inside the storage area. In extreme cases access could be limited to defined time periods depending upon the toxicity of the insecticide being used.

The incorporation of dead spaces into the design of buildings and fitments should be avoided. Where ducting and voids are necessary, inspection apertures should be fitted to allow cleaning and insect

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icidal treatments to be carried out as necessary.

4.6 Safety

As mentioned in Section 3.4 the risks associated with vapour inhalation are inherently more difficult to control than ingestion and dermal absorption - the two other main routes of entry of toxicants into the body. If low mammalian toxicity insecticides are used at the lowest effective doses then potential hazards to health are greatly reduced. Where vaporific insecticides are used, levels of airborne toxicants in the working environment should be monitored at regular intervals, using appropriate analytical techniques. This would serve to allay fears expressed by museum staff regarding the use of volatile insecticides, and would ensure that the institution was complying with its obligations under the Health & Safety at Work etc Act 1984 by ensuring, so far as is practicable, the health, safety and welfare of all employees. If a toxic hazard is identified then measures should be taken to reduce exposure as far as possible. As Cornwell(1976) states; M risks are best reduced by consciously creating the right conditions for maximum safety, plus the use of the least toxic materials at concentrations appropriate to greatest cost/efficiencyM.

4.7 Education and training

Curatorial staff should be trained to recognise the insect pests they are likely to encounter in their institution and the nature of the damage they can cause. It is often the case that staff do not recognise the adult insects found in their working environment as the mature stages of the larvae which damage collection material. Early recognition of a pest problem and the rapid instigation of control measures can prevent the spread of pests to other collection areas. Training should be given on the range of pest control procedures available for use in their institution. Where chemicals are used, potential hazards and requirements . for safety equipment should be notified , and where appropriate, training given in the handling and application of such chemicals. Pesticides should be applied in predetermined doses calculated to provide protection against pests for a known period of time. Reapplication should be carried out after a specified time interval so that the collection materials are pro

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tec ted continuously against pest attack. This would require systematic treatment of the collections, with records kept of dates of application, dosage, pesticide used, and the date for reapplication. Such an approach would prevent overdosing, or certain parts of the collection not being treated at all. Ultimately this would lead to more efficient pest management and staff resources could be allocated to pest control procedures at timetabled intervals. Under present policies pest control tends to be left to the discretion of individuals responsible for certain areas of the collection resulting in haphazard treatment being carried out when time is available, and control procedures not being taken seriously until pest damage has occurred to collections.

4.8 Establishment of a body responsible for conservation of natural history collections

There are numerous departments and committees associated with the conservation of archaeological, ethnographical, archival materials, paintings, monuments and buildings worldwide (e.g. see United Kingdom Institute for Conservation (1981) leaflet, 'Training in Conservation'), but none involved with natural history collections. There is a real need to establish such a body, not only to deal with pest control problems but for the preservation of natural history collections as a whol6. Many of the recommendations listed above could be dealt with by a conservation group responsible for undertaking research into new methods, developing pest control programmes, monitoring hazards and diseminating infromation about pests, pesticides, safety regulations and control procedures. Because of the sporadic nature of pest infestations it is envisaged that such a group would be responsible for advising museums nationwide and possibly further afield. Many of the smaller museums are particularly susceptible to severe pest and chemical damage through inappropriate methods, because of the lack of information on the effectiveness and hazards of chemical controls, and the lack of resources and knowledge to undertake effective action to deal with such problems.

Establishment of a natural history conservation group would be in line with the ever growing awareness of the urgent need to preserve and protect our heritage. Considerable funding and resources are allocated to the preservation of for example, fine works of art,

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scientifically and educationally natural history collections are probably more valuable. Further, with the ever increasing threat to wildlife through habitat destruction, these collections can no longer be considered as a renewable resource.

Ultimately instigation of a more scientific and controlled approach to conservation of collections can only be brought about by policy changes implemented by museum authorities at the senior level. This in turn is dependant upon such authorities understanding that a problem exists and realising their moral obligation to preserve the collections in their charge in the best conditions possible with minimal health risks to staff and visitors.

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REFERENCES

ABBOTT, W.S. & BILLINGS, S . C . (1935) F u r th er work showing t h a t p arad ich loro ben zene , naphthalene and cedar o i l s a re i n e f f e c t i v e as r e p e l l e n t s a g a i n s t c l o t h e s moths.J . econ. E n t . 28, pp. 493-495.

ADAMS, P . H . , WARREN, R. & HORLER, D .F . (1975) At t r a c t a nc y of long cha in f a t t y a c id sto Anthrenus v e r b a s c i . Pes t I n f e s t a t i o n Control Laboratory Report 1971-73. Pg. 207. M i n i s t r y of A g r i c u l t u r e F i s h e r i e s & Food.

ANON (1975) Ja ar b . p l z i e k t e n k . D i e n s t . 1973. Pg. 13.

ARBOGAST, R . T . & FLAHERTY, B .R . (1973) L i g h t responses of T r ibo l iu m castaneum and

T r ib o l iu m confusum (C o le o p te ra , T e n e b r io n id a e ) : v a r i a t i o n with age and sex .

J . s tored Prod. R e s . _9, pp. 31-35.

AREVAD, K. (1977) Eva lu a t i o n of methods f o r pr ot ec t i o n of b i r d s k in s a g a i n s t a t t a c k by

i n s e c t s . Ar sb er et h . S t . Skadedyr lab 1975-77. Pg. 20.

AYAPPA, P . K . , CHEEMA, P . S . & PERTI , S . L . (1957) A l i f e h i s t o r y study of Anthrenus

f l a v i p e s LeConte ( C o l . , D er m es t i d a e) . B u l l , en t . R es . 48 , p p . 185-198.

BAKER, R . J . & NELDER, J . A . (1978) The GLIM system. Re lease 3. G en er a l i s ed L i n e a r I n t e r

a c t i v e Model l ing . Numerical Algori thms Group, Mayfie ld Hse, Banburg Rd, Oxford.

BARAK, A.V. & BURKHOLDER, W.E. (1977) Behaviour and pheromone s t u d i e s with At tagenus

e Iongatu I us Casey (Co le o p te ra : De rm es t i d a e) . J . Chem. E c o l . _3> pp. 219-237.

BARLOW, F . & HADAWAY, A.B. (1968) I n t e r a c t i o n s between i n s e c t i c i d e s , c e l l u l o s e and

wat er , and t h e i r e f f e c t s on i n s e c t i c i d e t o x i c i t y and p e r s i s t e n c e . S o c ie t y of

Chemical Indust ry Monograph No. 99, London.

BARLOW, F . , HADAWAY, A . B . , FLOWER, L . S . , GROSE, J . E . H . & TURNER, C .R . (1977) Somelabo rat ory i n v e s t i g a t i o n s r e l e v a n t to the p o s s i b l e use of new p y re th r o id s in cont ro l of mosquito and t s e t s e f l i e s . P e s t i c . S c i . 8, pp. 291-300.

BEAL, R . S . (1960) D e s c r i p t i o n , b io logy and notes on the i d e n t i f i c a t i o n of some Trogoderma

l a r va e (C o leo p te ra : Dermest idae) . USDA Tech. B u l l . 1228, 26pp.

BEAUCHAMP, R . , KINGS0LVER, J . & PARKER, T . (1981) Reference l i s t i n g of museum p e s t s .In Edwards, S . R . , B e l l , B.M. & King , M.E. ( e d s . ) , Pes t Control in Museums: A S t a t u s

Report (1 980) . The A s s o c i a t io n of Sys tem at i c s C o l l e c t i o n s , U .S .A .

BECK, S .D . (1980) In se c t Photoper iod ism. 2nd. Ed. Academic P r e s s , New York. 387pp.

BEHRENZ, W. & NAUMANN, K. (1982) P r o p e r t i e s and p o t e n t i a l i t i e s of NAK 1654 ( f e n f I u t h r i n ) ,

a new p y re th r o id fo r the cont ro l of household, p u b l i c hea l th and s to re d-p ro duc t

p e s t s . P f Ia n ze ns ch ut z -N a c r i c ht en Bayer 35, p p . 309-349.

BELL, B.M. & STANLEY, E.M. (1981) Survey of pes t cont ro l procedures in museums. In

Edwards, S . R . , B e l l , B.M. & King , M.E. ( e d s . ) , Pes t Control in Museums: A S t a t u s

Report (1 98 0) . The A s s o c i a t io n of Sy s te m at i c s C o l l e c t i o n s , U .S .A .

BELL, C .H. (1982) The s i g n i f i c a n c e of diapause in the cont rol of i n s e c t p o p u la t i o n s .Annual Repor t , MAFF, ADAS, A g r i c u l t u r a l Sc ie n ce S e r v i c e Research & Development

Report . ' S torage Pes t s 1982' , pp .5 -9 .

BENTLEY, E.W. (1944) The b iology and behaviour of P t inu s t e c t u s Boie (C o le o p t er a ,P t i n i d a e ) , a pes t of s tored prod uc ts . V. Humidity r e a c t i o n s . J . exp. B i o l . 20 , p p . 152-158.

BILLINGS, S . C . (1934) Pa rad ich lorobenzene , naphthalene and the cedar o i l s i n e f f i c i e n t

as r e p e l l e n t s a g a i n s t c l o t h e s moth a d u l t . J . econ. E n t . 27, pp. 401-405.

-252-

BLAKE, G.M. (1955) A study of the ca rp e t b e e t l e , A . ver ba sc i ( L . ) . PhD t h e s i s . London U n i v . , 1955. 97pp.

BLAKE, G.M. (1958) Diapause and the r eg u l a t i o n of development in Anthrenus ve rb a sc i ( L . )

( C o l : Derm est id ae ) . B u l l , en t . R e s . 49 , pp. 751-775.

BLAKE, G.M. (1960) Decreas ing photoper iod i n h i b i t i n g metamorphosis in an i n s e c t .Nature , 188 (No.4745) , pp. 168-169.

BLAKE, G.M. (1961) Length of l i f e , fe cu n d i t y and o v i p o s i t i o n c y c l e in A . ve rb a sc i as

a f f e c t e d by ad u l t d i e t . B u l l , en t . R e s . 52 , p p .459-472.

BLAKE, G.M. (1963) Shorten ing of a d ia p a u s e -c o n t r o l l e d l i f e - c y c l e by means of i n c r e a s ing photoper iod. Nature , 198, p p .462-463.

BLAKE, G.M. (1970) An incomplete randomized b lock des ign, i l l u s t r a t e d by the study of humidi ty d i s c r i m i n a t i o n in A . v e r b a s c i . Anim. Behav. 18, pp .96-102.

BLAKE, G.M. (unpubl i shed) A c i r c a n n ua l c lo c k t iming growth, diapause and metamorphosis

in the ca rpe t b e e t l e , Anthrenus v e r b a s c i .

BLAKE, G.M. & BORRETT, R. (1952) Pes t I n f e s t a t i o n Control Laboratory Report 1952.Storage p e s t s .

BONHAG, P . F . (1958) ovar ian s t r u c t u r e and v i t e l l o g e n e s i s in i n s e c t s . Ann. Rev. E n t .

3, pp. 137-160.

BOTTIMER, L . J . (1929) Notes on parad ich lorobenzene and naphthalene as r e p e l l e n t s a g a i n s t

c l o t h e s moth l a r v a e . J . econ. E n t . 22, 570-573.

BROWN, V .K. (1980) Developmental s t r a t e g i e s in E c to b iu s p a l l i d u s ( D i c t y o p t e r a : B l a t t i d a e ) .

I n t . J . I n v e r t . Reproduction 2, pp. 85-93.

BUNING, J . (1979) The t e l o t r o p h i c nature of o v a r i o l e s of polyphage C o l eo pte ra . Zoomorphologie 93, pp. 51-57.

BURGES, H.D. (1959) S tu d ie s on the dermest id b e e t l e , Trogoderma granarium E v e r t s . I I . -

The occur rence of d iapause l a r va e a t a constant temperature, and t h e i r behav iour .B u l l , en t . R e s . 50, p p .407-422.

BURGES, H.D. (1959a) S t u d i e s on the dermest id b e e t l e , Trogoderma granarium E v e r t s . I I I . -

Ecology in mal t s t o r e s . Ann, a p p l . B i o l . 47 , pp .445-462.BURGES, H.D. (1960) S tu d ie s on the dermets id b e e t l e , Trogoderma granarium E v e r t s . I V . -

Feeding, growth and r e s p i r a t i o n with p a r t i c u l a r r e f e r e n c e to diapause l a r v a e .

J . Ins . P h y s i o l . 5, pp. 317-334

BURGES, H.D. (1962) S tu d ie s on the dermest id b e e t le Trogoderma granarium E v e r t s . V . -

Rea ct ions of d iapause l a r va e to temperature . B u l l , en t . R e s . 53, p p . 193-213.

BURKHOLDER, W.E. & DICKE, R . J . (1966) Evidence of sex pheromones in females of seve ra l

# s p e c i e s of Dermest idae. J . econ. E n t . 59, p p . 540-543.

BURKHOLDER, W.E . , KUWAHARA, M., MA, M. 8. MATSUMARA, Y. (1974) Sex pheromone of thef u r n i t u r e ca rp e t b e e t l e , Anthrenus f l a v i p e s (Co le o p te ra : Dermestidae) Can. Entomol . 106, p p . 835-839.

BUSVINE, J . R . (1966) I n s ec t s and hyg iene . Methuen, London. 467pp.

BUSVINE, J . R . (1971) A c r i t i c a l rev iew of the techn iques f o r t e s t i n g i n s e c t i c i d e s .2nd. ed. C .A .B . London. 345pp.

BUXTON, P .A. (1931) The measurement and cont rol of atmospher i c humidity in r e l a t i o n to

entomological problems. B u l l , en t . R e s . 22, p p .431-447.

CARTER, S.W. & CHADWICK, P .R . (1978) Permethr in as a re s id u a l i n s e c t i c i d e a g a i n s t

co ckroaches . P e s t i c . S c i . 9, p p . 555-565.

-253-

CHITTENDEN, F .H . (1895) Gran ivorous and other ha b i t s of c e r t a i n Dermest idae. B u l l . U .S . Bur . E n t . ( n . s . ) 8 , 14-24.

COFFELT, J . A . & BURKHOLDER, W.E. (1972) Reproduct ive b io logy of the c i g a r e t t e b e e t l e ,

Lasioderma s e r r i c o r n e . 1. Q u a n t i t a t i v e l aboratory b ioassay of the female sex pheromone from females of d i f f e r e n t ages . Ann. Entomol. Soc. Am. 65, pp .447-450.

COFFELT, J . A . & BURKHOLDER, W.E. (1975) Reproduct ive b io logy of the c i g a r e t t e b e e t l e , Lasioderma s e r r i c o r n e . 2. Ovar ian development and female sexual m a tu r i t y . Ann. Entomol. Soc . Am, 66, p p . 368-372.

COOMBS, C.W. & W00DR0FFE, G .E . (1983) The e f f e c t of temperature upon the l o n g ev i t y ,fe cu n d i t y and c i r c a n n ua l development of Anthrenus s a r n i c u s Mroczkowski (Co le o p te ra :

Dermestdae) . J . s tored Prod. R e s . 19, p p . 111-115.

CORNWELL, P . B . (1971) R i s i n g c o s t of damage by i n s e c t pes t s of f a b r i c s in B r i t a i n .I n t . Pes t Control 13, p p . 22-27.

CORNWELL, P .B . (1976) The Cockroach V o l . t l . I n s e c t i c i d e s and cockroach c o n t r o l .A . B . P . London. 557pp.

CRISAFULLI , S . (1980) Herbarium i n s e c t cont rol with a f r e e z e r . B r i t t o n i a 32, pg.224.

DESMARCHELIER, J .M. (1978) Mathematical examinat ion of a v a i l a b i l i t y to i n s e c t s of aged

i n s e c t i c i d e d ep o s i t s on wheat. J . s tored Prod. R e s . 14, p p . 213-222.

DETHIER, V.G. (1963) The phys io logy of i n s e c t s en s es . Wi ley , N.Y. 266pp.

DETHIER, V . G . , BROWNE, L . B . & SMITH, C .N. (1960) The des ig nat ion of chemica l s in terms

of the responses they e l i c i t from i n s e c t s . J . econ. E n t . 53, pg.134.

DETINOVA, T . S . (1968) Age s t r u c t u r e of i n s e c t popula t ions of medical importance. Ann. Rev. Entomol . 13, p p .427-450.

DICK, J . (1937) O v i p o s i t i o n in c e r t a i n C o le op ter a . Ann, a p p l . B i o l . 24, 762-796.

DINGLE, H. (1978) In t ro d u c t i o n , P a r t 2: Diapause, development and phenology. In

H. D ing le ( e d . ) , Ev o lu t i o n of I n s e c t Migrat ion and Diapause. Sp r in ge r V er la g ,New York. 284pp.

DUFF!ELD, P .A. (1977) Mothproofing with permethr in . P e s t i c . S c i . 8 , p p . 279-283.

EDWARDS, R. (1969) Anthrenus s a r n i c u s Mroczk. ( C o l : Dermest idae) . The pr ese nt s t a t u s

of t h i s i n s e c t in the B r i t i s h I s l e s . E n to m o lo g i s t ' s mon. Mag. 105, p p . 119-121.

EDWARDS, S . R . , BELL, B.M. & KING, M.E. (1981) Pes t cont rol in museums: A s t a t u s re p o r t

(1980) . The A s s o c i a t io n of Sy s tem at i c s C o l l e c t i o n s . U .S . A .

ENGELMANN, F . (1970) The phys io logy of i n s e c t re product ion . In t e r n a t i o n a l S e r i e s of

Monographs in Pure & Appl ied B io lo g y . Zoology D iv . Vo l . 44. Pergamon P r e s s .Oxford. 307pp.

ERICHS0N, W.F. (1846) Naturgesch i chte der Insecten Deutsch I ands 3_. B e r l i n .

FELT, E . P . (1909) Anthrenus verba sc i L i n n . J . econ. E n t . 2_, pg .193.

FELT, E . P . (1919) Anthrenus verbasc i L i n n . , a seventeen-year breeding re co rd .J . econ. E n t . 12, pg.273.

FINNEY, D . J . (1971) P r o b i t A n a l y s i s . 3rd. ed. Cambridge Un iv . P r e s s , Cambridge.

FUKUI, H . , MATSUMURA, F . , MA, M. & BURKHOLDER, W.E. (1974) I d e n t i f i c a t i o n of the sex

pheromone of the f u r n i t u r e ca rp e t b e e t l e . Tetrahedron L e t t e r s 40, p p . 3563-3566.

GANGESALINGHAM, V .K . (1974) Morphological s t u d i e s on the d i f f e r e n t i a t i o n in the ovary

of the a du l t S i t o p h i l u s zeamais Motschulsky (C o le op te ra : C u r c u l i o n i d a e ) . CeyI on J . S c i . ( B i o . S c i . ) 11, p p .1-4 .

-254-

GERBER, G.H. (1975) Reproduct ive behaviour and physiology of Tenebrio m o l i t or ( C o l -

eop+era: Ten eb r io n id a e) . I I . Egg development and o v i p o s i t i o n in young females and

t h e i r e f f e c t s of mating. Can. E n t . 107, p p . 551-559.

GRIFFITHS, K . J . (1959) Observat ions of the European pine sa w f ly , Neodiprion s e r t i f e r

( G e o f f . ) , and i t s p a r a s i t e s in southern O nt a r io . Can. E n t . 91 , p p . 501-512.

GRISWOLD, G.H. (1941) S tud ie s on the b io logy of four common ca rp e t b e e t l e s . P t . 1.The b lack ca rp e t b e e t le ( Attagenus p i c e u s ) , the va r ie d c a rp et b e e t le ( Anthrenus

v e r b a s c i ) , and the f u r n i t u r e ca rp e t b e e t le ( Anthrenus v o r ax ) . Mem. C o r n e l l , a g r i c .Exp. S t a . 240, pp. 3-57, 70-75 .

HALSTEAD, D.G.H. (1963) Ex terna l sex d i f f e r e n c e s in s tored products Co l eo p te ra . B u l l , e n t . Res . 54, pp. 119-134.

HALSTEAD, D.G.H. (1975) Changes in the s t a t u s of i n s e c t p es t s in s torage and domestic h a b i t a t s . P roc . 1 s t , i n t . Wkg. C on f . S tored-Prod . E n t . , Savannah 1974. p p . 142-153.

HAMMACK, L . & BURKHOLDER, W.E. (1976) C i r c a d ia n rhythm of sex pheromone-releas ing

behaviour in females of the dermest id b e e t l e , Trogoderma glabrum: Regu la t ion by

photoper iod . J . I n s ce t P h y s i o l . 22, pp. 385-388.

HAPP, G.M. & WHEELER, J.W. (1969) B i o a s s a y , p r e l im in a ry p u r i f i c a t i o n and e f f e c t of age,

crowding and mating on the r e l e a s e of sex pheromone by female Tenebrio m o l i t o r .Ann. Entomol. Soc. Am. 62, pp. 846-851.

HAPP, G.M. (1970) Maturat ion of the response of male Tenebrio m o l i t or to the female

sex pheromone. Ann. Entomol. Soc.Am. 63, pg.1782.

HEALTH & SAFETY EXECUTIVE (1984) Occupat ional Exposure L i m i t s 1984. Guidance Note EH40.HMS0.

HERRICK, G.W. (1934) A c r i t i c a l examinat ion of two papers on moth r e p e l l e n t s . J . econ.E n t . 28, p p . 1095-1099.

HERRICK, G.W. & GRISWOLD, G.H. (1931) Parad ichIorobenzene as a fumigant f o r the

immature s tages of c l o t h e s moths. J . econ. E n t . 24, p p .420-425.

HERRICK, G.W. & GRISWOLD, G.H. (1933) Naphthalene as a fumigant f o r the immature

s tages of c l o t h e s moths and ca rp e t b e e t l e s . J . econ. E n t . 26, p p .446-451.

HEWER, H.R. (1934) S tu d ie s in Zygaena ( L e p i d o p t e r a ) . Par t I I . The mechanisms of copu l a t i o n and the passage of sperm in the female . P roc . Zool . Soc . London 1934, pp. 513-527.

HINTQN, H .E . (1943) Natural r e s e r v o i r s of some b e e t le s of the fam i ly Dermestidae

known to i n f e s t s tored products , with notes on those found in s p id er webs.Pr o c . R. e n t . Soc . Lond. (A) 18, p p . 33-42.

HINTON, H . E . (1945) A monograph of the b e e t l e s a s s o c i a te d with s tored produ cts . Vo 1.1 . B r i t i s h Museum (Nat . H i s t . ) , London.

HOWE, R.W. (1953) The rap id determinat ion of the i n t r i n s i c r a t e of i n c r ea s e of an

i n s e c t po p u l a t i o n . Ann, a p p l . B i o l . 40, p p . 134-151.

HOWE, R.W. (1957) A l aboratory study of the c i g a r e t t e b e e t l e , Lasioderma s e r r i c o r n e ( F . )

( C o l . , Anobi idae) with a c r i t i c a l rev iew of the l i t e r a t u r e on i t s b io lo g y .B u l l , e n t . Res . 48 , pp.9 -5 6 .

HOWE, R.W. (1971) A parameter f o r ex p re ss in g the s u i t a b i l i t y of an environment f o r

i n s e c t development. J . s tored Prod. R e s . 7, p p .63-65.

IMAMURA, S . (1935) On the o l f a c t o r y and v i s u a l senses of Anthrenus verbasc? L . ( D er m es t i d a e) . B u l l , s e r i c . Exp. S t a . Japan 9, pp .1-21 .

KLEIN, J . A . & BECK, S .D. (1979) A m e r id i c d i e t f o r Trogoderma glabrum and other Dermestid b e e t l e s . Ann. E n t . Soc. Am. 72, p p . 398-404.

-255-

KUNIKE, G. (1939) Neure E r g e b n i s s e uber d ie E ia b la g e und G en era t i on s fo Ige der Anthrenus

Arten Vo r l a u f i g e M i t t e i l u n g . Anz . SchadI ingsk 15, p p . 80-84.

KUWANA, Z. (1950) Reversal of pho+o+ropism and o v i p o s i t i o n h a b i t of the a d u l t s of

Anthrenus verb asc i ( D er m es t id a e) . Oyo-Dobutsugaku Zasshi 16, p p .78-81 .

LAUDANI, H . , BRY, R . E . & McDONALD, L . L . (1959) A new method of using l indane c r y s t a l sf o r p r o t ec t i n g boxed wool lens a g a i n s t f a b r i c - i n s e c t damage. J . econ. E n t . 52, p p . 525-527.

LINNAEUS, C. (1767) Byr rhus ve rb a sc i L . Systema Naturae , 12th .ed . pg. 568.

MA,M. & BURKHOLDER, W.E. (1978) Sex pheromone r e l e a s i n g behaviour of Anthrenus f l a v i p e s

( F u r n i t u r e ca rp e t b e e t l e ) females (Co le o p te ra : Derm est id ae ) . Ann. Entomol. Soc. Am.71_, pp. 129-133.

MA, M., BURKHOLDER, W.E. & CARLSON, S .D. (1978) Supra-anal organ: a d ef en s iv e mechanism

of the f u r n i t u r e ca rp e t b e e t l e , Anthrenus f l a v i p e s (C o le op te ra : De rmest idae) .Ann. Entomol. Soc . Am. 71 , p p . 718-723.

MARSH, D. (1975) Responses of male aphids to the female sex pheromone in Megoura

v i c ? a e Buckton. J . econ. E n t . 50, p p .43-64.

MORDUE, W. (1965) S tud ie s on oocyte product ion and a s s o c i a te d h i s t o l o g i c a l changes in

the neuroendocr ine system of Tenebr io mo l i t or L . J . I n s e c t P h y s i o l . 11, p p .493-503.

MROCZKOWSKI, M. (1962) Anthrenus s a r n i c u s s p . n . ( C o l . Dermest idae) from the I s l an d of Guernsey. Ann. & Mag, of Nat. H i s t . S e r . 13 v o l . V, pp. 697-700.

MROCZKOWSKI, M. (1968) D i s t r i b u t i o n of the Dermestidae (C o leoptera ) of the world with

a ca ta logue of a l l known s p e c i e s . Annales Zoo log ic i Warszawa 15, pp. 15-191.

NUTTING, W.L. & SPANGLER, H.G. (1969) The h a s t i s e t a e of c e r t a i n dermest id l a r va e :

an entang l ing defense mechanism. Ann. Entomol. Soc . Am. 62, p p .763-769.

PAPW0RTH, D .S . (1975) R e g i s t r a t i o n procedures and f a i l - s a f e procedures . P roc . 4 t h . B r .

Pes t Control A ss . C o n f . , J e r s e y . Paper No.2, 7pp.

PARKIN, E .A . & W00DR0FFE, G . E . (1961) The ha b i t s and cont ro l of c a rp et b e e t l e s and

wool ly b e a r s . The S a n i t a r i a n 69, p p . 297-301.

PEACOCK, E . R . ( p e r s . comm.) Dept, of Entomology, B r i t i s h Museum (Natura l H i s t o r y ) ,

Cromwell Road, London SW7.

PEACOCK, H.A. (1955) E lementary Microtechn ique 2nd. ed. Edward Arno ld , London.

PHILL IPS , F . Y . (1971) P e r s i s t e n c e of o rganoch lor ine i n s e c t i c i d e s on d i f f e r e n t subs t r a t e s under d i f f e r e n t environmental c o n d i t i o n s . I . The r a t e s of loss of d i e l d r i n

and a l d r i n by v o l a t i l i s a t i o n from g la s s s u r f a c e s . P e s t i c . S c i . 2, 255-266.

PIEL0U, D .P . & GUNN, D .L . (1940) The humidity behaviour of the mealworm b e e t le Tenebr iom o l i t or L . - I . The r e a c t i o n s to d i f f e r e n c e s of humid ity . J . exp. B i o l . 17, pp. 286-294.

PINNIGER, D .B . (1983) Res idua l i n s e c t i c i d e s . How wel l do they perform a g a i n s t s tored product pe s t s ? Proceedings of the 6th B r i t i s h Pes t Control Conference, 1983,Ses s i on 4 , Paper 9 , 13pp.

RODIN, J . O . , SILVERSTEIN, R.M. , BURKHOLDER, W.E. & GORMAN, J . E . (1969) Sex a t t r a c t a n t

of female dermest id b e e t l e , Trogoderma inclusum LeConte. Sc ie nc e 165, pp. 904-906.

RYCKMAN, R . E . (1969) Vapona f o r the cont rol of museum p e s t s . J . Med. E n t . 6, pg. 98.

SCHOFIELD, E . K . & CRISAFULLI , S . (1980) A s a f e r i n s e c t i c i d e fo r herbarium use .B r i t t o n i a 32 . pp. 58-62.

SCUDAMORE, K . A . , PINNIGER, D.B. & HANN, J . J . (1980) Study of d i c h lo r vo s s l o w - r e l e a s e

u n i t s used in museum ca ses f o r the p r ot ec t i o n of specimens a g a i n s t i n s e c t i n f e s t a t i o n .

T r in g Museum 1978-79. Pes t Control Chemistry De pt . , Report No.45. M in i s t r y of A g r i c u l t u r e , F i s h e r i e s & Food, Slough Labo rato ry , England.

-256-

s h o r t , D .E . & HILL , R . E . (1972) Adu lt emergence, ovar ian development and o v i p o s i t i o n sequence of the western corn rootworm in Nebraska. J . econ. E n t . 65, p p .685-689.

S IEGEL , S. (1956) Nonparametric s t a t i s t i c s f o r the behavioural s c i e n c e s . Mc.Graw-Hi l l New York . 312pp.

SMEREKA, E . P . & HODSON, A .C . (1959) Some humidi ty and l i g h t r e a c t i o n s of the granary

w e e v i l , S i t o p h i l u s g r an a r i u s ( L . ) (C o le op te ra : CurcuI i o n i d a e ) . Can. E n t . 91, p p . 784-797.

SOLOMON, M.E. (1945) The use of co b a l t s a l t s as i n d i c a t o r s of humidity and mois ture .Ann, a p p l . B i o l . 32, pp .75-85 .

SOLOMON, M.E. (1951) Control of humidi ty with potassium hydrox ide , s u l p h u r i c ac id or

othe r s o l u t i o n s . B u l l , en t . R e s . 42 , p p . 543-554.

SOLOMON, M.E. (1957) Es t i ma t i o n of humidity with c o b a l t th io c y an a te papers and permanent

co lo u r s ta nd ard s . B u l l , e n t . R e s . 48 , pp. 489-

SPANGLER, H.G. (1965) React ions of the l a rva e of the khapra b e e t le and Trogoderma

p a r a b i l e to c e r t a i n food substances and o rgan ic compounds. J . econ. E n t . 58, p p . 212-218.

SPENCER, G . J . (1963) Control of pes t s in i n s e c t and herbarium c a b i n e t s . P roc . entomol . s o c . B r i t . Columbia . 60 , p p . 23-26.

STANLEY, E. (1981) Annotated b i b l io gr a p hy of the l i t e r a t u r e p e r ta i n i n g to pes t c o n t r o l .In Edwards, S . R . , B e l l , B.M. & King, M.E. ( e d s . ) , Pest Control in Museums: A s t a t u s

Report (1980) . The A s s o c i a t io n of Sys tem at i c s C o l l e c t i o n s , U .S .A .

STANLEY, E . & McCANN, M. (1981) Tec hn ica l re p o r t s on p e s t i c i d e s used in museums. In

Edwards, S . R . , B e l l , B.M. & King , M.E. ( e d s . ) , Pest Control in Museums: A s t a t u s

Report (1980) . The A s s o c i a t io n of Sy s te m at i c s C o l l e c t i o n s , U .S .A .

STUBBS, M. & GRIFFIN, R. (1983) The response of Oryz aeph i lus sur inamens i s ( L . ) ( C o le o pt er a : S i l v a n i d a e ) to water . B u l l , en t . Res . 73, p p . 587-595.

SURTEES, G. (1961) SpermatthecaI s t r u c t u r e s in some Co leoptera a s s o c i a t e d with s tored

prod uc ts . P roc . R . E n t . Soc . L o n d . (A ) 36 , p p . 144-152.

TANNERT, W. (1960) Zur F rage des Schutzes von Insekten sammlungen gegen Anthrenus spec ,

( c o l e o p t . De rm es t i d a e) . Anz. Sc ha d l ing sk 33, p p . 87-92.

TAUBER, M.J. & TAUBER, C .A . (1976) Developmental requi rements of the u n i v o l t i n e s p e c i e s

Chrysopa downesi : photoper iod ic s t i m u l i and s e n s i t i v e s ta g e s . J . I n s e c t P h y s i o l .22, p p . 331-335.

TAUBER, M.J . & TAUBER, C .A . (1978) E vo lu t io n of phenolog ical s t r a t e g i e s in i n s c e t s : a

comparat ive approach with e c o -p h y s io lo g i c a I and g enet i c c o n s i d e r a t i o n s . In H.

D ing le ( e d . ) , E vo lut ion of I n s e c t Migrat ion and Diapause . S p r in g e r - Ve r l ag , New York . 284 pp.

TSUDA, S . , YOSHIDA, K. & 0KUN0, Y. (1983) Empenthrin f o r f a b r i c p es t c o n t r o l . Soap and Chemical S p e c i a l i t i e s Dec. 83.

UNITED KINGDOM INSTITUTE FOR CONSERVATION OF HISTORIC AND ARTISTIC WORKS (1981) .T r a i i n g in Co n ser vat io n . UCIC, c/o Conservat ion De pt . , Tate G a l l e r y , M i l l b an k ,London SW1P 4RG.

VICK, K.W. , DRUMMOND, P . C . & COFFELT, J . A . (1973) Trogoderma inclusum & T . gIabrum:E f f e c t s of t ime of day on product ion of female pheromone, male res p o ns iv en es s

and mating. Ann. Entomol. Soc. Am. 66, pp.1001 -1004.

VICK, K.W., DRUMMOND, P . C . , SOWER, L . L . & COFFELT, J . A . (1973a) Sex pheromone habi t - ,

u a t io n : The e f f e c t s of h a b i t u at io n on the pheromone response l evel of Trogoderma

i ncIusum (C o leo p te ra : D er m es t i d a e) . Ann. Entomol. Soc. Am. 66, pp. 667-670.

-257-

WALDBAUER, G.P. (1978) Pheno log ica l adaptat ion and polymodal emergence p a t t e rn s of i n s e c t s . In H .Dingle ( e d . ) , Ev o lu t i o n of I ns ec t Migrat ion and D iapause . Spr inger

Ve r l a g , New York. 284 pp.

WEAST, R . C . & ASTLE, M.J . (1982) ( e d s . ) . CRC Handbook of Chemistry and p h y s i c s : ar e a d y - re fe r en ce book of chemical and p hy s i ca l data . 63rd. ed. Boca Raton, F l o r i d a .

WILLIS , E . R . & ROTH, L.M. (1950) Humidity r e a c t i o n s of T r ibo l ium castaneum ( H e r b s t ) .

J . exp. Zoo I . 115, p p . 561-588.

W00DR0FFE, G .E . (1953) An e c o lo g i c a l study of the i n s e c t s and mi tes in the nes t s of c e r t a i n b i rd s in B r i t a i n . B u l l , en t . R e s . 44, p p . 739-772.

W00DR0FFE, G .E . (1961) Natural so urces of domestic i n s e c t s : A fundamental approach f o r the stored products entomolog i s t . The s a n i t a r i a n March 1961.

W00DR0FFE, G .E . (1967) Anthrenus s a r n i c u s Mroczkowski (Co le op te ra , Dermest idae) in

B r i t a i n . J . s tored Prod. R e s . _3, p p . 263-265.

W00DR0FFE, G .E . & HILL , P . J . (1969) Observat ions on a new c arp et b e e t l e . Pes t I n f e s t .

Res . 1968. pg .5 .

W00DR0FFE, G .E . & SOUTHGATE, B . J . (1954) An i n v e s t i g a t i o n of the d i s t r i b u t i o n and f i e l d

h a b i t s of the va r ie d ca rp et b e e t l e , Anthrenus verbasc i ( L . ) ( C o l . , Dermest idae) in

B r i t a i n , with comparat ive notes on A . fuscus O l . , and A . museorum ( L . ) B u l l , en t .

R e s . 45 , pp. 575-583.

WORTHING, C .R . & WALKER, S . B . ( e d s . ) (1983) The P e s t i c i d e Manual. A World Compendium. 7t h . ed. B r i t i s h Crop Pr o te c t i o n C o u n c i l . London. 695 pp.

YOSHIDA, K . , TSUDA, S. & OKUNO, Y . (1984) P r a c t i c a l a p p l i c a t i o n of empenthrin as a

mothproofer of t e x t i l e . Sen-I Gakka ishi 40, pp. 121-130.

-258-

APPENDIX I

GLIM model results - Tables of means, standard errors and 3-way analysis of variance showing the effects of sex, temperature and humidity on larval development and adult emergence weight for larvae reared in constant conditions.

Key * s i g n i f i c a n t a t p 0 . 05 , * * s i g n i f i c a n t a t p ^ 0 . 01 , * * * s i g n i f i c a n t a t p 0.001 N.S. no s i g n i f i c a n t d i f f e r e n c e

(a) Duration of the larval period (weeks)

_______________ MALE___________ ___________FEMALE_________15

Tempi17.5

Brature20

°c25 30

20 - - 52.8l2*1

58.32.6

-

hum

to

O

- 46.6 + 1.7

56.6l2-1

-

a 70 u

87.1 +!5.2

45.9+2.1

44.6 + 1 *4

46.1 + 1.5

46.5 +_2.8

^ 90 41.3_+2.0

47.9+2.4

15Temp*17.5

Brature20

°C25 30

- - 56.1+2.0

62 .9+2 . 4

-

- - 47 .6

+ 1.6

60 .8

+2.1

-

92 .7+5.3

47 .4

+2.2

46 .9

+ 1.6

48 .8+1.5

46.5

+3.5

42 .7

l1 -749.1

i2*4

Source S . S . d . f . M.S. F - r a t i o

Sex ......................... . S 760 1 760.0 7 . 6 * *Humidity . . . . H 9250 3 3083.3 92 .5 * * *Temperature. . . T 3890 3 1296.6 38 .9 * * *S .T 100 3 33.3 1 . 0 N .S .S.H 70 3 23.3 0 . 7 N.S.T.H 1650 3 550.0 16.5 * * *S .H .T 50 3 16.6 0 . 5 N.S.Residua I 50700 507 100.0Tota I 66470 526

(b) Percentage of larvae surviving to pupation

»

15Ternpei1 7 . 5

rrature2 0

°c2 5 3 0

2 0• - - 53.8 37.2 -

j l 3 0 - - 74.7 53.2 -

”0)705-i

66.0 85.7 87.8 86.0 52.5

^ 9 0 - - 66.7 38 .8 -

(c) Number of larval moultsMALE FEMALE

-259-

15Temp17.5

erature20

°c25 30

20•

E

- - 8 .5+0.3

11 .7

+0.4

-

* 30 - - 7.1

+0.3

10.1+0.3

-

2 70 7.5+0.2

5 .6jK) .3

6 .4+0.2

8 . 7+0.2

12.0_+0.4

90 8 .9+0.3

12.1+0.4

15Tempei17.5

rature20

°c25 30

- - 9 .5+_0.3

12.8+0.4

-

“ — 7.3+0.3

10.9

+0.3

—

8.2+0.3

5 .9+0.4

7 . 0+0.3

9 . 7_+0.2

13.1

+0.6— 8.9

_+0.3

12.4

+0.4


S e x ......................... . S 63010 1 63010.0 25204.0 * * *Humidity . . . . H 604 3 201.3 241.6 * * *Temperature. . . T 1554 3 518.0 621 .6 * * *

S . T 9 3 3 . 0 3 . 6 N.S.S.H 11 3 3 .7 4 . 6 *+T.H 15 3 5 . 0 6.0 * * *

S .H .T 0 3 0.0 0 . 0 N.S.Res i duaI 1267 507 2 .5Tota I 66470 526

(d) Adult emergence weight (mg)MALE FEMALE

15Ternpe17.5

srature20

°C25 30

20•

- - 3.72+0.26

2.88_+0.33

-

1 30- -

4 .27

jÔ.22

3.42

+0.21 -

« 70J-l

3 .88

+0.25

5.62+0.27

5.70

+0.18

3.72 _+0.19

3.69

_+0.35

8-8 90 4.43

+0.25

2 .18

+0.31

“

15Tempe17.5

.rature20

°c25 30

- - 2.72

+0.25

3.79

+0.31

-

- -4 .77

+0.21

4 .49+0.26 -

4 .37+0.23

6 .24

jfO.286.24

+0.21

4 .23+0.20

3.82

+0.45

' '

5 .06_+0.22

3.11+0.30 '


S e x ......................... ..... S 65062 1 65062.0 40664.0 * * *Humidity . . . ,, H 221 3 73.7 138.1 * * *Temperature. . ,. T 251 3 83.6 156.6 * * *S . T 10 3 3 .3 g #4 •***

S.H 14 3 4 . 6 8.8 * * *T.H 90 3 30.0 56 .2 * * *S . H .T 13 3 4 . 3 8.1 * * *Res i duaI 809 507 1.6Tota I 66470 526

APPENDIX II

Temperature and daylength records

A. Weekly maximum and minimum temperatures recorded in a laboratory at Ashurst Lodge, Silwood Park, Ascot, Berkshire between 24.2.'83 and 26.7.’84.

B. Weekly maximum and minimum temperatures recorded in a pigeon loft at Silwood Park, Ascot, Berkshire between 2.7.’82 and 26.7.'84.

Daylength records (including civil twilight) for latitude 50°Nare taken from Beck (1980) whose table was compiled from U.S.Naval Observatory data.

9 ♦

A P P E N D I X III

(a) duration of larval period

D ie t

No.pupati ng

Me?n per iod (weeks) S . E .

Standard r e a r i n g medium 24 42 .2 0.86Dr ied b e e t l e s 25 33.3 2.27

Woo 11en mater ia 1 11 66 .4 3.93Woollen mater ia l + yea s t & c h o l e s t e r o l 20 46 .8 1.69

F l o o r sweepings 16 53.5 3.23Human h a i r 13 47.1 1.48Sparrow nes t mater ia l 19 45.1 1.20Pigeon guano 20 41 .9 0 .84

Oak t r e e l eaves 0 - -

Herbarium specimens 0 - -

A n a l y s i s of va r ia n ce

Source S . S . d . f . M.S . F - r a t i o

L ar va l per iod 10082.5 7 1440.4 20.37 * * *

Res i duaI 9898.2 140 70 .7Tota I 19980.7 147

(b) adult emergence weight

D ie t No.

M$anweight

(mg) . S . E .

Standard r e a r i n g medium 24 5.48 0 .18

Dr ied b e e t l e s 25 5.34 0.21Woollen mater ia l 11 2.43 0 .18

Woollen mate r ia l + yea s t & c h o l e s t e r o l 20 2.90 0.15

F l o o r sweepings 16 3.12 0 .27

Human h a i r 13 2.94 0.20Sparrow nes t mater ia l 19 4.54 0 .27

Pigeon guano 20 4 .37 0 .17

Oak t r e e l eaves 0 - -Herbarium specimens 0 - -

A n a l y s i s of va r ia n ce


Emergence weight 182.1 7 26 .0 31.1 * * *

Res i duaI 117.3 140 0.8Tota I 299.4 147

Effects of larval diet on (a) duration of the larval period and (b) adult emergence weight.

*** indicates significance at p < 0.001

-263-

APPENDIX IV

Dissection results for 'field* collected beetles at the British Museum (Natural History) in 1983.

KeyM = male F = female+ = + standard error

-264

Date

c o l l .

No.caught

Body len

M (n)

gth (mm)F (n)

A v . f a t bo

M (n)

dy s i z e

F (n)

Nop ol l en in

M ( * )

. with gut conter

F (%)

i t s

Tota l (56)

Av .ovary

s tage (n)

No.of females

with sperm

(n) ( ? )

22.4 2 3.1 (2)

_+ 0 .05

- 3 .5 (2) +_ 0 .50

- - - - - -

2 9 . r - 06 .5 1 2 . 7 (1 ) — 3. 0 (1) “

' '

13.5 0

20.5 3 3 . 0 (2)

_+ 0 .05

3 .3 (1) 3 . 0 (2) +_ 0 .00

3 . 0 (1) — 3 . 0 (1) 0 (1 ) ( 0 . 0 )

27.5 0

3 .6 2 3 . 3 (2) _+ 0 . 10

3 . 0 (2) +_ 0 .00

“'

10.6'" 5 2 . 9 (2)

+_ 0 . 00

3 .3 (2)

+_ 0.25

1.8 (2)

_+ 1.252.0 (2)

+_ 0 .00

2.5 (2)

+_ 0 .50

0 (2 ) ( 0 . 0 )

T T T ~ 29 3 . 0 (21)

_+ 0 . 073.1 (6)

_+ 0.11

2 .5 (21)

+_ 0 .161 .6 (7)

+_ 0 .17

2 . 9 (7)

+_ 0 .143 (7 ) ( 4 2 . 9 )

24 .6" 47 3.1 (32)

+_ 0 .053.1 (13)

+_ 0 .062 .6 (32)

_+ 0 .161.6 (15)

+ 0 .20* ”* 2 .9 (13) 5 ( 1 3 ) ( 3 8 . 5 )

~ T 7 T 40 3 . 0 (22)

_+ 0 .05

3.2 (14)

+0.10

2.0 (22)

_+ 0 .191 .9 (14)

+_ 0 .24

3 (1 3 . 6 ) 1 (7 .1 ) 4 (1 1 . 1 ) 2 . 8 (14) jh 0 .12

7 (14) ( 5 0 . 0 )

~ E T 7 ~

15 .7

107

142

3 . 0 (63) _+ 0 .043 . 0 (54)

_+ 0 .03

3.1 (39)

_+ 0 .033.1 (81)

+_ 0 .03

2 .2 (63) _+ 0 .09

2.1 (56)

_+ 0.11

1 .6 (39)

_+ 0.12 1.2 (85)

+_ 0 .08

4 ( 6 . 4 )

7 (1 2 .5 )

4 (10 .2 )

15 (1 7 . 7 )

8 ( 7 . 9 )

22 (1 5 . 6 )

3.1 (37)

_+ 0 .063.1 (82) + 0.04

15 (39) ( 3 8 . 5 )

40 (85) ( 4 7 . 1 )

'22.7' 73 3 . 0 (30)

+_ 0 .053.2 (41)

+_ 0 .031.9 (30)

_+ 0 .141.5 (43)

_+ 0.11

2 ( 6 . 7 ) 9 (2 0 . 9 ) 11 (1 5 . 1 ) 3.1 (43)

+ 0.06

16 (43) ( 3 7 . 2 )

'79T7- 31 3 . 0 (13)

+_ 0 .083.1 (18) _+ 0 .06

2.1 (13)

_+ 0.251.5 (18)

_+ 0 .20

2 (1 5 .4 ) 4 (22 .2 ) 6 (1 9 . 4 ) 3.1 (18) + 0.14

10 (18) ( 5 5 . 6 )

5 .8 14 3 .2 (5)

+_ 0 . 173 .2 (9)

_+ 0 .103 . 0 (5)

+_ 0.55

1.3 (9)

+_ 0.25 ' '3.1 (9)

+ 0.11

3 (9 ) ( 3 3 . 3 )

12.8 15 2 . 9 (5)

_+ 0 . 073 .0 (10)

+_ 0 .06

1.6 (5) +_ 0 .24

0 . 7 (10)

_+ 0.11 '3 .2 (10)

+ 0.13

2 (10) ( 2 0 . 0 )

19.8 7 2 . 9 (2)

_+ 0 .053.1 (5)

_+ 0 .06

2.0 (2)

+_ 0 .001.1 (5) +_ 0 .37 ' ' '

3 .2 (5)

+ 0 .20

2 (5 ) ( 4 0 . 0 )

76TB- 2 2.8 (1) 2 .7 (1) 2.0 (1) 0 .5 (1) 3 . 0 (1) 1 (1) ( 1 0 . 0 )

2 .9 5 2 . 9 (2)

_+ 0 .053 .2 (3) _+ 0 .06

2.0 (2)

+ 0 .00

0 . 8 (3)

_+ 0 .17

3 .3 (3)

+ 0.33

1 (3 ) ( 3 3 . 3 )

9 . 9 1 2 .9 (1) — 1.0 (1) 3 . 0 (1) 0 (1 ) ( 0 . 0 )

16.9 3 2.8 (1) 3 .2 (2)

_+ 0.050 .5 (2)

_+ 0 .10

— 3. 0 (2)

+ 0 .10

2 (2 ) (100)

23 .9 130 .9 07.10 1

TOTALS 531I

3 .0 (2 70 ) 3 . 1 (246) 2 .2 (270) 1 .4 (256) 18 ( 6 . 7 ) 33 (12 .9 ) 51 ( 9 . 7 ) 3 .0 (2 48) 1 0 7 ( 2 5 0 ( 4 2 . 3 )

Dissection results for beetles collected from window sticky traps at the Entomology Building in 1983.

9

Date

c o l l .

No.caught

Body ler

M (n)

lgth (mm)

F (n)

A v . f a t be

M (n)

dy s i z e

F (n)

pol ten

M (%)

No

i n

F

with

gut con

(56)

t e n t s

T o t a I(%)

Av.ovary

s tage (n)

No. of

with

(n)

femaIes

sperm

(56)

11.5 7 2 . 8 (4)

+_ 0 .00

2 .9 (3 )

_+ 0.12

1.5 (4 )

_+ 0 .29

1.7 (3)

_+ 0 .88

— ~ 2 . 7 (3 ) 2 (3) (6 6 . 7 )

17.5 2 2 . 7 (1 ) 3 .0 (1) 1 (1) 0 (1) — 3 (1) 0 (0) ( 0 . 0 )

3 .6 10 2 .8 (9 )

+_ 0 .072,5 (1 ) 2 . 7 (9)

+_ 0 .421 (1) —

9 .6 31 2 .8 (24)

+_ 0.05

3 .0 (6 )

+_ 0 .09

2 .6 (24)

+_ 0 .25

0 . 8 (6 )

_+ 0.21 ' ' '3 .4 (5 ) 2 (5 ) (4 0 . 0 )

15.6 41 2 . 9 (33)

+_ 0 .04

3 . 0 (7 )

_+ 0 .082 .3 (33)

_+ 0.15

1.4 (7)

+_ 0 .23

3.1 (7 ) 4 (7 ) (5 7 .1 )

23.6 78 2 . 9 (58)

+_ 0 .03

3.1 (9 )

_+ 0.052.1 (62)

+_ 0 .09

0 . 7 (10)

_+ 0 .13

3 .2 (9) 4 (10) ( 4 0 . 0 )

30 .6 100 2 . 9 (58)

+_ 0 .03

3.1 (28)

_+ 0.05

1 .9 (60)

_+ 0 .101.1 (30)

_+ 0 .123 .3 (27) 13 (30) (4 3 . 3 )

7 .7 183 3 . 0 (120)

+_ 0 .023.1 (58)

+_ 0 .031 .8 (120)

_+ 0 .09

1.2 (60)

_+ 0 .103.1 (56) 29 (60) (4 8 . 3 )

14.7 139 2 . 9 (63)

_+ 0 .03

3.1 (70)

+_ 0.02

1.8 (65)

_+ 0 .13

0 . 9 (74)

_+ 0 .08

3.1 (67) 33 (74) (4 4 . 6 )

21.7 138 2 . 9 (50)

+_ 0 .03

3.1 (82)

_+ 0 .02

1 .9 (50)

_+ 0 .120 . 9 (88)

+_ 0 .08

3.1 (83) 29 (88) (3 3 .0 )

28.7 50 3 . 0 (14) +_ 0 .07

3.1 (35)

_+0.032.5 (14) _+ 0.21

1.6 (36) _+ 0 .09

— 3. 0 (36) 18 (36) (5 0 .0 )

4 . 8 43 3 . 0 (15)

_+ 0 .073 . 0 (26)

_+ 0.05

1.2 (16)

+_ 0 .17

1.3 (27)

_+ 0 .16 ' '3 .2 (24) 8 (27) (2 9 . 6 )

11.8 8 2 . 8 (2 )

+_ 0 .10

3 . 0 (6 )

_+ 0 .06

1.5 (2)

+_ 0 .50

0 . 9 (6 )

^ 0 .27

— 3 .2 (6) 3 (6) (5 0 . 0 )

19.8 2 3.1 (2 )

+_ 0 .10 '0 . 5 (2)

0 .50

“ 3 . 0 (2 ) 0 (2) ( 0 . 0 )

25 .8 3 2 .7 (1) 3.2 (2)

_+ 0.052 (1) 0 . 5 (2)

+_ 0 .53 . 0 (2) 0 (2) ( 0 . 0 )

1.9 2 2 . 7 (1 ) 3 .4 (1 ) 2 (1) 1.5 (1) — 3 . 0 (1 ) 0 (1 ) ( 0 . 0 )

8 . 9 3 2 . 8 (1) 3 . 0 (2) 2 (1 ) 0 . 8 (2) - - 3 . 0 (1 ) 1 (2) (5 0 .0 )

TOTALS 840 2 . 9 (454) 3 . 0 (339) 1 .9(463) 1 .0(356) - - - 3 .1 (3 31) 146(356) (4 1 . 0 )

Dissection results for beetles collected from window sticky traps at the General Herbarium in 1983

-265-

» »

Datec o l l .

No.

caughtBody ler

M (n)gth (mm)

F (n)A v . f a t be

M ( n )

>dy s i z e

F (n)

po IM (%)

No. with

len in gut c

F (%)

ontents

T o t a K * )

Av .ovary

s tage (n)

No.of females

with sperm

(n) (%)

23 .6 11 2 . 9 (7)

_+ 0 .093 .2 (4 )

_+ 0 .061.3 (7)

_+ 0 .29

0 . 9 (4 )

+_ 0 .13

1 (1 2 . 5 ) 0 ( 0 . 0 ) 1 ( 9 . 1 ) 3 .3 (4 ) 2 (4 ) (5 0 . 0 )

30 .6 6 2 .8 (2)

_+ 0 .33

3.1 (4 )

+_ 0 .33

1.5 (2) 1.5 (3) 1 (5 0 . 0 ) 1 (2 5 . 0 ) 2 (3 3 . 3 ) 3.5 (4) 1 (4 ) (2 5 . 0 )

7 .7 27 2 . 0 (16)

_+ 0 .063 .2 (10)

_+ 0 .081.5 (16)

_+ 0.150 . 8 (11)

+_ 0 .16

8 (5 0 .0 ) 9 ( 8 1 . 8 ) 17 (6 3 . 0 ) 3 .4 (9) ~ 1 (9 ) (1 1 .1 )

14.7 62 3 . 0 (27)

+_ 0.053.1 (30)

+_ 0 .04

1.7 (30)

+_ 0 .191.5 (32)

_+ 0 .16

13 (4 3 . 3 ) 12 ( 3 7 . 5 ) 25 (4 0 . 3 ) 3 .2 (29) 17 (29) (5 8 .6 )

21.7 60 3 . 0 (30)

+_ 0 .043.1 (29)

+_ 0 .05

1 .9 (30)

+_ 0 .171.1 (30) _+ 0.12

16 (5 3 . 3 ) 10 ( 3 3 . 3 ) 26 (4 3 . 3 ) 3.1 (23) 11 (30) (3 6 . 7 )

28.7 29 3 . 0 (14)

_+ 0.053.1 (14)

+_ 0 .081.4 (14)

_+ 0 .300 . 6 (15)

i ° - 15

6 (4 2 . 9 ) 4 ( 2 6 . 7 ) 10 (3 4 . 5 ) 3 .3 (12) 6 (15) (4 0 . 0 )

4 .8 20 3 . 0 (8)

_+ 0 .08

3.1 (11)

_+ 0 .06

2.1 (8)

+_ 0 .29

1.2 (12)

_+ 0.21

3 (3 7 .5 ) 3 ( 2 5 . 0 ) 6 (3 0 . 0 ) 3 .3 (9) 3 (12) (2 5 . 0 )

11.8 12 3 .2 (7)

_+ 0 .073.1 (5 )

+_ 0.151.1 (7)

1 0 .24

0 . 4 (8)

_+ 0 .101 (1 4 .3 ) 1 ( 2 0 . 0 ) 2 (1 6 . 7 ) 2 . 6 (5 ) 2 (5 ) (4 0 . 0 )

19.8 2 3.1 (2 )

+ 0.15

“ 0 . 5 (2)

+ 0 .00

0 ( 0 . 0 ) 0 ( 0 . 0 ) 3 .5 (2) 0 (2 ) ( 0 . 0 )

25.8 1 2 . 9 (1) 2 (1) 0 ( 0 . 0 ) — 0 ( 0 . 0 ) “*

1.9 2 3 . 0 (1) 3.1 (1 ) 3 (1) 2 (1) 0 ( 0 . 0 ) 0 ( 0 . 0 ) 0 ( 0 . 0 ) 3 . 0 (1) 0 (1 ) ( 0 . 0 )

TOTALS 232 3 .0 (113)

_+ 0 .033 .1 ( 110 ) +_ 0 .02

1 .8 (116)

+_ 0 .06

1 .1 (118)

_+ 0.05

49( 42 . 2 ) 40 (34 .8 ) 89 (3 8 . 5 ) 3 .2 (98)

_+ 0 .06

43(109) (3 9 .5 )

Dissection results for beetles collected on outdoor sticky-traps in the grounds of the BM(NH) in 1983.

-266-

Datec o l l .

No.

cauqht

Body le

M (n)

ng+h (mm)

F (n)

A v . f a t be

M ( n )

jdy s i z e

F (n)

pol

M (%)

No. with

len in gut cc

F (%)

intents

Total ( ? )

Av.ovary

s tage (n)

No.of females

with sperm

(n) (Jt)

7 .7 2 - 3 . 0 (2)

+_ 0.15

- 0 . 8 (2 )

*_ 0 .25

- 1 (5 0 . 0 ) 1 (5 0 . 0 ) 3 (2) 1 (2 ) (5 0 . 0 )

14.7 6 2 . 9 (3)

_+ 0.12

3.1 (3)

_+ 0 .06

0 . 3 (3)

+_ 0 .33

0 . 8 (3)

+_ 0 .17

3 (100) 3 (100) 6 (100) 3 (3 ) 1 (3 ) (3 3 . 3 )

21 .7 10 2 . 9 (5)

+0.143 . 0 (5)

+_ 0 .181.2 (5 )

+_ 0 .581.5 (5)

+0.39

5 (100) 4 (8 0 .0 ) 9 (9 0 . 0 ) 3 (5) 2 (5 ) (4 0 . 0 )

28.7 2 3.1 (2)

j+ 0 .10

0 . 5 (2 ) 2 (100) 2 (100) 3 (2) 1 (2 ) (5 0 . 0 )

4 . 8 5 2 . 7 (2)

+_ 0 .203 . 0 (3 )

+0.090 . 8 (2 )

0.35

0 . 7 (3) _+ 0 .17

2 (100) 3 (100) 5 (100) 3 (3) 2 (3 ) (6 6 .6 )

11.8 2 2 . 9 (1) 3 . 0 (1) 1.5 (1 ) 2 (1 ) 1 (100) 0 ( 0 . 0 ) 1 (5 0 . 0 ) 2 (1) 1 (1 ) (100)

TOTALS 27 2 .9 (11)

+_ 0 .083 . 0 (16)

+_ 0 .071 .0 (11)

+_ 0 .10

1.1 (16)

+_ 0 .10

11(100) 13 (8 1 . 3 ) 24 (8 8 . 9 ) 2 .8 (16) _+ 0 .09

8 ( 1 6 ) ( 5 0 . 0 )

Dissection results for beetles collected on flowers in the grounds of the BM(NH) in 1983

-267-

APPENDIX V

Parameters of probit regression equations for different life-stages of A. i . a . v J L p n ^ , k . 6 a n . Y u i c . v L 6 and A . v e A b a A C J i exposed to the contact and fumigant activities of insecticide deposits on glass for 24 hours at 25°C.

Key * = significant at p < 0.05, ** = significant at p < 0.01,*** = significant at p < 0.001, N.S. = no significant difference.

Insecticides: PDB=paradichlorobenzene, NAP=naphthalene, DICH= dichlorvos, EMP=empen thrin, DIAZ=diazinon, PMET=pirimiphos- methyl, CHLM=chlorpyrifos-methyl, LIN=lindane, I0D0=iodophenphos, CYP=cypermethrin, FMC=FMC 54800.Stage: A=adult, E=early instar larva, L=late instar larva, P=pupa, 0=egg.Exposure conditions: F=fumigant, C=contact.

A nth.fiQ.YWi6 1{ZavZpe.4

LC50 (mg/m2)

95% conf j I imi

Lower

(jience

UpperLC50

(mg/m2)

95% conf jI imi

Lower

dencet s

UpperSlope

b _+ S . EHeterogene i ty

X2 df Prob

PDB A F 86 .02 61.99 117.1 645.1 405 .6 1311 1.88+0.24 0 .10 i N.S.C 91 .39 63.95 124.7 585.8 377.7 1172 2.04+0.29 0 .13 1 N.S.

E F 54.47 35.79 85.85 1030 464 .9 4068 1.29+0.19 5.36 2 N.S.C 50.01 - - 1090 - - 1 .23+0.39 8 .87 2 *

L F 303.1 214.1 43 2 .0 3064 1665 8758 1.64+0.25 0 . 08 1 N.S.C 320.3 231.1 452 .6 2935 1640 7750 1.71+0.24 0 .54 1 N.S.

NAP A F 209.8 166.5 250.3 607.0 472 .8 934.6 3.57+0 .58 0.05 1 N.S.C 104.5 - - 1219 - - 1 .54+0.53 5 .67 1 *

E F 89.54 70.22 114.35 378.67 256.37 738.64 2 .63+0.40 3 .38 2 N.S.C 92 .96 72.74 121.69 470.62 304.75 r 955.92 „ 2.34+0.32 0 .97 3 N.S.

4 3 5 6 5 91 F 1.67x10 5.88x10 3 .37x10 , 1 .63x10_ 1.31x10, 5 .23x1 0 . 0 .83+0.22 0 .04 1 N.S.4 5 4 6 —

C 9587 5414 2.63x10 3.40x10 8.36x10 6.68x10 1.06+0.20 0 .13 2 N.S.

DICH A F 0 .17 0 .07 0 .29 8 .76 2.61 271.3 0 .96+0.24 2.32 3 N.S.C 0.11 - - 2.52 - - 1 .16+0.46 6.43 2 *

E F 0 .82 0.55 1.65 13.04 4.31 271.5 1.37+0.33 0 .14 1 N.S.C 0 .36 0 .28 0 . 49 1.58 0 .97 3.91 2.55+0.42 1.18 1 N.S.

L F 0 .67 0.54 0 .83 2 .38 1.75 3.86 2.99+0.39 0 .46 3 N.S.C 0 .74 0.55 0 .94 3.53 2.35 7.35 2.42+0.40 0 . 17 2 N.S.

25 4 32 —P F 73.75 7.21 1.62x10 5.73x10 254.9 5.60x10 0.57+0 .27 0 . 18 2 N.S.

EMP A F 3 .77 2.42 6 .68 73.92 29 .18 394.2 1.27+0.20 0 .92 1 N.S.C 0 .12 0 .10 0 .15 0 .46 0 .34 0.75 2.88+0.39 2 .87 1 N.S.

E F 1.16 0.84 1.72 8 .98 4 .75 29.20 1.85+0.30 2.41 2 N.S.C 0 .19 0 .14 0 . 26 1.30 0 .74 3.88 1.38+0.35 1.38 1 N.S.

L F 1.31 0.92 1.87 11.89 6 .77 29.21 1.72+0.23 0 .54 1 N.S.C 0.31 0.21 0 . 47 3 .20 1.58 11.93 1.61+0.27 0.85 2 N.S.

DIAZ A F 0 . 20 0 .13 0.31 2.48 1.08 15.28 1.49+0.30 0 . 87 2 N.S.C 0 .02 0.01 0 . 04 0.91 0.25 25.25 0 .99+0.23 1.55 2 N.S.

E F 0 .43 0 .26 0 . 88 12.83 3 .86 187.5 1.12+0.23 2.71 1 N.S.C 0.05 0 .03 0 . 09 2 .68 1.00 15.97 0.95+0 .16 1.29 2 N.S.

L F 1.03 0 .72 1 .47 9.55 5 .47 23.15 1.70+0.23 0 .96 1 N.S.C 0 .17 0.15 0 . 2 0 0.45 0 .35 0 .67 3 .96+0.58 0 . 48 2 N.S.

PMET A F 0 .44 0 .22 0 .75 22 .07 8.34 149.7 0 .97+0.18 0 .72 2 N.S.C 0 . 08 0 .06 0.11 0 . 40 0 .23 1.10 2.34+0.39 1 .88 2 N.S.

E F 4 . 37 - - 60 .76 - - 1 .44+0.56 7.75 1 * *

C 0 . 10 0 . 07 0 .13 0 .69 0 . 40 1.79 1.92+0.29 2.05 2 N.S.L F 7 .10 4.79 11.05 105.1 49 .63 382.1 1.41+0.21 3 .34 2 N.S.

C 0.11 0 .09 0 .15 0 .63 0 .38 1.53 2 . 1 9_+0.33 0 . 04 2 N.S.

CHLM A F 0 .28 0 .10 0 .54 28.22 8 .90 367.8 0 .82+0 .17 1.19 2 N.S.C 0 . 07 0 .06 0 . 0 9 0 .32 0 .20 0.75 2.48+0.39 3.01 2 N.S.E F 2.81 1.97 3 .96 24 .27 14.38 55.39 1.76+0.23 5 .78 3 N.S.11 —C 0 .07 0.01 1.03 0.81 0.21 4.41x10 1.58+0.46 9 . 0 0 3 *

L F 3.69 2.42 5 .80 85.51 2 .42 294.3 1.21+0.16 0 .52 1 N.S.C 0 . 10 0 .08 0 .13 0 .56 0.35 1.21 2.14+0.29 1.24 1 N.S.

A n t k > i e j U L 6 ^ Z a v X , p 2.6 ( c o v t i d )

LC50 (mg/m2)

95/5 confjc I Imi

Lower

jencefsUpper

LC95 (mg/m2)

95% conf i 1 imr

Lower

denceFsUpper

Slope

b +_ S . EHeterogene i ty

X2 df Prob

LIN A F 1.11 0 .76 1 .67 22.56 10.45 84 .78 1.26+0.18 3.55 2 N.S.C 0 .06 - - 0 .39 - - 2.40+0.73 4 .94 1 *

E F 1.68 1.30 2.24 8 .78 5.51 19.48 2.29+0.34 2.43 1 N.S.C 0 .04 0 .03 0.05 0 .27 0 .18 0 .57 1.99+0.29 1.21 3 N.S.L F 6.83 - - 281.0 - - 1.02+0.40 15 .0 2 * * *

C 0 .17 - - 1.96 - - 1 .62+0.54 12.3 2 * *

IODO A C 0 .25 0 .19 0 .33 1.17 0 .73 2.79 2.44+0.41 5.62 3 N.S.E c 0 .12 0 .08 0 . 18 3.01 1.56 8 .92 1.18+0.17 3 .10 3 N.S.L c 4.01 2.82 5 .93 58 .07 30 .20 157.9 1.42+0.17 2.03 2 N.S.

■8 -8 -8 -6 -7 -5CYP A c 4.07x10 1.91x10 8.27x10 _ 2.56x10 _ 8.66x10 1.59x10 0.92+0 .14 3.14 1 N.S.

■7 -7 -7 -5 -5 -4 —E c 2.92x10 O 1.41x10 6.10x10 3.34x10 1.03x10 2.19x10 0.80+0.11 0 .29 1 N.S.L c 8.95x10 - - 2.22x10 5 - - 0 .69+0.22 4 .62 1 *

FMC A F 260.0 _ 1198 _, 2.48+1.02 10 .8 2 * *-4 -3c 0.001 4.14x10 1.49x10 0 .07 0 .02 0 .48 0.86+0 .14 0 .27 1 N.S.

E F 162.5 121 .2 203.3 683.8 499 .6 1146 2 .64+0.40 1.81 1 N.S.C 0.001 6.62x10 0.002 0 . 06 0.02 0.35 0.97+0.15 0 .62 1 N.S.L F 394.7 - - 727.9 - - 6 .20+3.08 7.52 1 •**

C 0.11 0 .06 0.21 3 .77 1.31 28.79 1.08+0.19 0 .28 1 N.S.

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Antkn.e.nu.4 6an.yu,c.u6 (c.ontd)

LC50

(mg/m2)

95% c<j>i?fj<

Lower

jence■sUpper

LC95(mg/m2)

95% confj< I imr

Lower

dence'SUpper

Slope

b +_ S . EHeterogene ity

X2 df Prob

LIN A F 0 .60 0 .44 0.81 5.14 3.11 11.59 1.77+0.24 2.14 1 N.S .C 0 .07 0 .06 0 .09 0.31 0.21 0 .56 2.56+0.35 0.64 2 N.S.

E F 1.64 1 .27 2.20 8 .93 5 .56 20.03 2.24+0.33 3.20 1 N.S.C 0.02 0.02 0 .03 0.12 0 . 08 0.21 2.37+0.32 1.28 1 N.S.

L F 3.72 2.04 5.87 90.33 42 .66 352.7 1.19+0.20 1.24 2 N.S.C 0.10 0 .08 0 .13 0.42 0 . 28 0.86 2.68+0.43 0.13 2 N.S .

P F 8 .41x1 05 - - - - - 0.24+0.24 1.89 2 N.S .

IODO A C 0.20 0 .16 0 .25 0.75 0 .52 1 .41 2.89+0.45 1.51 2 N.S .E C 0.04 0.01 0 . 06 1.14 0 .49 8.83 1.10+0.25 2.35 2 N.S.L C 1.26 0.88 1.92 26.69 12.44 90 .50 1 .24+0.16 1.10 3 N.S .

, „ -9 -10 -9 -6 -7 -5CYP A C 3.03x10 7.95x10 8.08x10 1.71x10 3.76x10 r 2.84x10 0.60+0 .10 1.06 1 N.S .—V -7 -7 -5 -5

E C 2.26x10 9.40x10 5.35x10 8.79x10 1.96x10 0.001 0.64+0.09 0.88 1 N.S.-5 —5 -4 —

L C 4.32x10 1.97x10 1.06x10 0.021 0 .004 0.311 0.61+0 .08 4.11 2 N.S .

FMC A F 228.9 653.5 3.61+1.86 9.73 1 *"*—5 -5 *4

C 5.75x10 1.87x10 1.45x10 0.03 0 .007 0.45 0 .61+0 .10 2.91 2 N.S .E F 170.0 127.9 213.1 650.7 457 .7 1260.5 2 .82+0.50 3.03 2 N.S

C 0.001 1.96x10 4 0.001 0 .13 0 .03 2.72 0.68+0.12 0 .17 1 N.S.L F 376.2 - - 671.6 - - 6 .54+3 .08 14.4 2 * * *

C 0 .32 0.21 0 .62 8.03 2.62 88.3 1.18+0.23 2.55 1 N.S .

273-

Anth.n.e.nu.4 veAba.4c.ji

LC50

(mg/m2)

95% conf i I imi

Lower

dencets

Upper

LC95

(mg/m2)

95% confj I imt

Lower

dencet s

UpperSI ope

b +_ S . EHeterogene i ty

X2 df Prob

4 3 5 5 4 7NAP L F 1.79x10 8 . 80 x 1 0 , 1. 11x10r 5 .43x10 , 9 .45x10, 9 . 7 4 x 1 0 , 1.11+0.29 1.56 1 N.S .

, 4 3 5 5 4 7C 1.76x10 8.89x10 1.00x10 4.47x10 8.46x10 6.22x10 1.17+0.30 0 . 46 1 N.S.

DICH L F 0 .96 0 .58 4 .19 20.12 4 .42 1.17x106 1.24+0.48 0.20 1 N.S .C 0.51 0 . 3 8 0 .70 3 .38 1.92 10.33 1.99+0.35 0 . 78 1 N.S .

EMP L F 143.7 62 .2 1293 1 .50x104 1 .53x103 2. 68x10? 0.82+0.23 0.55 1 N.S .C 5.12 2.92 16.87 134.5 31 .40 5768 1.16+0.27 0 .65 1 N.S.

CHLM L F 1.22 0.88 1.70 8 .59 5.21 18.92 1.94+0.26 0.61 3 N.S .C 0.12 0.10 0 .16 0 . 60 0 .37 1.33 2.38+0.35 2.46 1 N.S .

LIN L F 6 .37 4 . 18 10.20 121.8 53.49 514.0 1.28+0.19 1.21 2 ' N .S .C 0 .13 0.10 0 .19 1.50 0 .79 4 .39 1.56+0.22 4 .60 2 N.S .

IODO L C 1.41 1.07 1.88 8 .28 5.11 18.98 2.14+0.32 0 . 69 1 N.S .-4 -6 5

CYP L C 1.76x10 6.04x10 0.004 0.006 0.001 1.12x10 1.07+0.28 11.2 3 *

FMC L F 391.5 348.5 438 .4 729.7 606.5 1046 6 .09+1.10 1.87 1 N.S .C 0.15 0 .09 0 . 26 3 .08 1.21 19.45 1.25+0.23 0.71 1 N.S.

spiral.imperial.ac.uk€¦ · -2-ABSTRACT A study of the biology and control of the dermestid beetle, Anthsizmi* Mroczk., recently introduced into Britain and now a serious pest in

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