P Peterson 1 , SV Fowler 2 , M Merrett 3 and P Barrett 4 1 LCR, PN, 2 LCR, Chch, 3 The Open Polytechnic of NZ, Lower Hutt, 4 Massey University, PN

P Peterson1, SV Fowler2, M Merrett3 and P Barrett4

1LCR, PN, 2LCR, Chch, 3The Open Polytechnic of NZ, Lower Hutt, 4Massey University, PN

Heather beetle impact assessment

Heather (Calluna vulgaris)

Spreading- Te Aroha

- Rotorua- Tarawera- Pureora- Mt Egmont National Park- Hokitika- Mt Cook- Queenstown- Te Anau

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Photo by Shaun Forgie

Heather beetle (Lochmaea suturalis)

Impact assessment

Assessment area

Treatments:Herbicide (2,4-D ester)Heather beetleControl

Beetle vs herbicide

Design:3 treatments4 blocks 2 reps per block

Vegetation cover

• Pre-treatment

• 50 x 50 cm

Merilyn Merrett estimating vegetation cover

Plant co de (*e x o tic) Scie ntific name C o mmon name Initial % co v e rCalvul* Ca llu na vu lg aris hea the r 42.49H iepil* H iera c iu m p ilo se lla mouse-ea r haw kw eed 7.98Rac lan Ra co mitriu m la n ig u no su m w oolly moss 6.52Chirub Ch io n o ch lo a ru b ra red tussock 5.00Copche Co p ro sma cheesema n ii spraw ling coprosma 4.83P oac it Po a c ita silve r tussock 4.29P enpum Pen ta cho n d ra p u mila mounta in hea th 4.27W ahpyg Wa h len b erg ia p yg ma ea harebell 3.78D rasub D ra co ph y llu m su b u la tu m monoao 3.35A grcap* Ag ro stis ca p illa ris brow ntop 3.28Lycfas Lyco p o d iu m fa stig ia tu m mounta in c lubmoss 2.07Celgla Celmisia g la n d u lo sa dow ny da isy 1.90Celgra Celmisia g ra cilen ta dainty da isy 1.56Leufra Leu co p o g o n f ra seri patota ra 1.41Eupcun Eu p h ra sia cu n ea ta common eyebright 1.15Coppet Co p ro sma p etrie i prostra te coprosma 1.14Gaumac G a u lth eria ma cro stig ma prostra te snow berry 1.09H yprad* H yp o ch oeris ra d ica ta catsea r 1.06Lotped* Lo tu s p ed u n cu la tu s lotus ma jor 0.78M ueaxi M u eh len b eck ia a x illa ris c reeping pohuehue 0.73D eyave D eyeu xia a ven o id es mounta in oa tgrass 0.57O zolep O zo th amn u s lep to p h ylla tauhinu 0.43A ntodo* An th o xan th u m o d o ra tu m sw ee t vernal 0.42Gerses G era n ium sessilif lo ru m c ranesbill 0.42Epi sp Ep ilo b iu m sp. 0.36H ollan* H o lcu s la n a tus Y orkshire fog 0.31Lincat* Lin u m c a th a rticu m purging flax 0.21Luzcol Lu zu la co len so i dw arf a lpine w oodrush 0.21M icrotis M icro tis u n if o lia onion orchid 0.21P oacol Po a co len so i blue tussock 0.21A cicol Acip h y lla co len so i giant spania rd 0.10Fesrub* Festu ca ru b ra Chew ings fe scue 0.10Cyacol Cya th od es co len so i w as Leucol 0.05M icsca M icro seris sca p ig era native dande lion 0.05P immic Pimelea microp h y lla Stra thmore w eed/pinatoro 0.05Rytse t Rytid o sp erma se tif o liu m bristle tussock 0.05The ly Th e lymitra sp. sun orchid 0.05V iocun Vio la cun n in gh a mii w hite viole t 0.05

37 v

ascu

lar s

peci

es37 vascular common

25 dicot species• 20 native• 5 exotic

12 monocot species• 8 native• 4 exotic

9 vascular uncommon Native and exotic, i.e. sedges,

lilies, grasses, etc.

Applied treatments

• No beetle establishment• Herbicide impacts were interesting

Beetle vs herbicide

2002–2011

Herbicide only assessment

Before and after photos

Control

2011

Herbicide

2002

Heather (Calluna vulgaris)

Monoao (Dracophyllum subulatum)Sprawling coprosma (C.cheesemanii)

Mountain heath (Pentachondra pumila)Tauhinu (Ozothamnus leptophylla)

Native dicotyledons

Hawkweed (Pilosella officinarum)

All monocotyledons

Browntop (Agrostis capillaris)Yorkshire fog (Holcus lanatus)

Red tussock (Chionochloa rubra) Silver tussock (Poa cita)

Red tussock (Chionochloa rubra)

Browntop (Agrostis capillaris)

Summary (herbicide only assessment)

• Four herbicide applications kill 80% of heather but signs of recovery 4 years later

• Heather may recover faster than dicot natives?

• Monocot cover (both native and exotic) increases following herbicide application

• Heather cover doubled in 9 years if nothing was done

Summary (herbicide only assessment)

• Four herbicide applications kill 80% of heather but signs of recovery 4 years later

• Heather may recover faster than dicot natives?

• Monocot cover (both native and exotic) increases following herbicide application

• Heather cover doubled in 9 years if nothing was done

Summary (herbicide only assessment)

• Four herbicide applications kill 80% of heather but signs of recovery 4 years later

• Heather may recover faster than dicot natives?

• Monocot cover (both native and exotic) increases following herbicide application

• Heather cover doubled in 9 years if nothing was done

Summary (herbicide only assessment)

• Four herbicide applications kill 80% of heather but signs of recovery 4 years later

• Heather may recover faster than dicot natives?

• Monocot cover (both native and exotic) increases following herbicide application

• Heather cover doubled in 9 years if nothing was done

But what about the beetles?

Difficult to establish

Released (1996–2009)36 000 all stages78 sites

Establishment9 outbreaks (9%)2 false starts

Impact assessment (beetle vs herbicide – 2nd attempt)

Assessment area

Beetle vs herbicide

Beetle feeding damage visible in 2007

2007

Small heather beetle outbreak

Plots set up outside beetle-damaged area

2007

IH+I

H

4 treatments, 6 blocks assigned

2007

2007– ?

IH+I

H

Predicted beetle dispersal

Vegetation cover

• Pre-treatment

• 50 x 50 cm

Merilyn Merrett estimating vegetation cover

Plant code (*exotic) Scientific name Common name Initial % coverCalvul* Calluna vulgaris heather 75.55Rac sp. Racomitrium sp. woolly moss 24.96Chirub Chionochloa rubra red tussock 5.91Drasub Dracophyllum subulatum monoao 3.93Copche Coprosma cheesemanii sprawling coprosma 3.64Piloff* Pilosella officinarum mouse-ear hawkweed 3.52Agrcap* Agrostis capillaris browntop 2.58Poacol Poa colensoi blue tussock 1.95Mueaxi Muehlenbeckia axillaris creeping pohuehue 1.72Ozolep Ozothamnus leptophylla tauhinu 1.39Poacit Poa cita silver tussock 1.33Lotped* Lotus pedunculatus lotus major 1.08Penpum Pentachondra pumila mountain heath 0.99Wahpyg Wahlenbergia pygmaea harebell 0.81Hyprad* Hypochoeris radicata catsear 0.65Lycfas Lycopodium fastigiatum mountain clubmoss 0.55Celgra Celmisia gracilenta dainty daisy 0.49Gonmic Gonocarpus micranthus 0.36Epi sp Epilobium sp. 0.29Gerses Geranium sessiliflorum cranesbill 0.21Leufra Leucopogon fraseri patotara 0.16Coppet Coprosma petriei prostrate coprosma 0.13Viocun Viola cunninghamii white violet 0.13Hydrocotyle Hydrocotyle novae-zelandiae var. montana pennywort 0.10Pimpro Pimelea prostrata 0.10Gaumac Gaultheria macrostigma prostrate snowberry (also see G.depress ) 0.08Hollan* Holcus lanatus Yorkshire fog 0.08Eupcun Euphrasia cuneata common eyebright 0.05Luzcol Luzula colensoi dwarf alpine woodrush 0.05Rytset Rytidosperma setifolium bristle tussock 0.05Stacmin Stackhousia minima 0.05Celgla Celmisia glandulosa downy daisy 0.03Gaudep Gaultheria depressa var. novae-zelandiae mountain snowberry 0.03

Other categoriesLichen 13.14Litter 8.59Bare ground 0.94Bryophyte mosses 0.84

32 v

ascu

lar s

peci

es32 vascular common

25 dicot species• 21 native• 4 exotic

7 monocot species• 5 native• 2 exotic

15 vascular uncommon Native and exotic, i.e. sedges,

lilies, orchids, grasses, etc.

Applied treatmentsTreatment Code EffectDo nothing Beetle impact

Spray insecticide(Karate zeon: lambda-cyhalothrin)

I Heather protected

Spray herbicide(Pature Kleen: 2,4-D ester )

H Beetle + Herbicide impact

Spray herbicide + insecticide H+I Herbicide impact

2008

2009

2009

2009

2009

Unsprayed (heather beetle impact) Herbicide (beetle + herbicide impact)

Insecticide (heather protected) Herbicide + insecticide (herbicide impact)

Initial observations

• Almost all heather dead following beetle feeding and/or 3 herbicide applications

• No non-target damage from beetle feeding

• Again, significant non-target damage from herbicide application to dicots

Initial observations

• Almost all heather dead following beetle feeding and/or 3 herbicide applications

• No non-target damage from beetle feeding

• Again, significant non-target damage from herbicide application to dicots

Dracophyllum subulatum

Chionochloa rubra Coprosma cheesmanii

Pentachondra pumila

Initial observations

• Almost all heather dead following beetle feeding and/or 3 herbicide applications

• No non-target damage from beetle feeding

• Again, significant non-target damage from herbicide application to dicots

Dracophyllum subulatum

Vegetation cover

• post-treatment (2009 & 2010)

• 50 x 50 cm

Merilyn Merrett estimating vegetation cover

Heather (Calluna vulgaris)

Monoao (Dracophyllum subulatum)Sprawling coprosma (C.cheesemanii)

Mountain heath (Pentachondra pumila)Tauhinu (Ozothamnus leptophylla)

Native dicotyledons

Mouse-ear hawkweed (Pilosella officinarum)

Catsear (Hypochoeris radicata)Lotus major (Lotus pedunculatus)

Exotic dicots minus heather

All monocotyledons

Browntop (Agrostis capillaris)Yorkshire fog (Holcus lanatus)

Red tussock (Chionochloa rubra) Silver tussock (Poa cita)

Red tussock (Chionochloa rubra)

Browntop (Agrostis capillaris)

Summary (beetle vs herbicide)• Beetle feeding kills 99% of heather vs 90%

after 3 herbicide applications• No non-target damage from beetle feeding

but significant damage to dicots from herbicide application

• Some evidence for dicot response after beetle feeding but too early to be sure

• All monocots trending upwards following heather removal by either method

Summary (beetle vs herbicide)• Beetle feeding kills 99% of heather vs 90%

after 3 herbicide applications• No non-target damage from beetle feeding

but significant damage to dicots from herbicide application

• Some evidence for dicot response after beetle feeding but too early to be sure

• All monocots trending upwards following heather removal by either method

Summary (beetle vs herbicide)• Beetle feeding kills 99% of heather vs 90%

after 3 herbicide applications• No non-target damage from beetle feeding

but significant damage to dicots from herbicide application

• Some evidence for dicot response after beetle feeding but too early to be sure

• All monocots trending upwards following heather removal by either method

Summary (beetle vs herbicide)• Beetle feeding kills 99% of heather vs 90%

after 3 herbicide applications• No non-target damage from beetle feeding

but significant damage to dicots from herbicide application

• Some evidence for dicot response after beetle feeding but too early to be sure

• All monocots trending upwards following heather removal by either method

Conclusions (both experiments)

• Both methods are effective for killing heather• Herbicide non-target impacts can significantly

alter vegetation composition after 9 years• More time required to assess full impact of

heather removal by beetle feeding but no non-target damage seen

• Exotic monocot invasion seems inevitable using either method if close to a seed source

• Doing nothing will result in more heather

Conclusions (both experiments)

• Both methods are effective for killing heather• Herbicide non-target impacts can significantly

alter vegetation composition after 9 years• More time required to assess full impact of

heather removal by beetle feeding but no non-target damage seen

• Exotic monocot invasion seems inevitable using either method if close to a seed source

• Doing nothing will result in more heather

Conclusions (both experiments)

• Both methods are effective for killing heather• Herbicide non-target impacts can significantly

alter vegetation composition after 9 years• More time required to assess full impact of

heather removal by beetle feeding but no non-target damage seen

• Exotic monocot invasion seems inevitable using either method if close to a seed source

• Doing nothing will result in more heather

Conclusions (both experiments)

• Both methods are effective for killing heather• Herbicide non-target impacts can significantly

alter vegetation composition after 9 years• More time required to assess full impact of

heather removal by beetle feeding but no non-target damage seen

• Exotic monocot invasion seems inevitable using either method if close to a seed source

• Doing nothing will result in more heather

Conclusions (both experiments)

• Both methods are effective for killing heather• Herbicide non-target impacts can significantly

alter vegetation composition after 9 years• More time required to assess full impact of

heather removal by beetle feeding but no non-target damage seen

• Exotic monocot invasion seems inevitable using either method if close to a seed source

• Doing nothing will result in more heather

Acknowledgements

We would like to thank John Mangos (New Zealand Army) for continued support, Lawire Cairns for aerial photography, and Lindsay Smith (LCR) and Andrew Blayney (Massey University) for help with field work.

This project has been funded by the Ministry for Science and Innovation (formally the Foundation for Research, Science and Technology) Contract No. C09X0210, and the New Zealand Army.

Scale of beetle feeding impact

1 km

1 km

2001–2004

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1 km

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2005 (1 m²)

1 km

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2006 (25 m²)

1 km

2007 (¼ ha)

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1 km

2008 (1½ ha)

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1 km

2009 (4½ ha)

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1 km

2010 (17 ha)

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1 km

2011 (80 ha)

.