PESTICIDE APPLICATION TRAINING Cooperative Extension Service Manhattan, Kansas Category 7B Stored Products Pest Control
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PESTICIDE APPLICATION TRAINING
Cooperative Extension ServiceManhattan, Kansas
Category 7B
Stored ProductsPest Control
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Table of ContentsIntroduction 3
Stored-Product Insects 4How Stored-Product Insects MultiplyInternal Grain-Infesting InsectsOther Stored-Product (External) Insects
Monitoring for Stored-Product Insects 15Monitoring Methods
Cockroaches 19Biology and BehaviorCommon SpeciesCockroach Control
Food-Plant Pest Treatment Areas 24Areas of ConcernForms of Pesticide Chemicals
Grain Handling 28Preharvest PreparationHarvest OperationsPost-Harvest OperationsUse of Sprays and Protectants
Fumigation of Stored Products 32FumigantsPreparation for FumigationRespiratory Protection DevicesFumigant ApplicationPost FumigationCommodities/Pests to Consider for
Fumigation
Fumigation Methods for Stored Grain 39General
Fumigation of Structures, Facilitiesand Other Enclosures 41
Types of Fumigants 45Threshold Limit ValuesSafe Use of FumigantsSafety PrecautionsFumigation References
Vertebrate Pests 51RodentsControl TechniquesBird Damage Control
Directions for Using this ManualThis is a self-teaching manual. At the end of each major section is a list of study questions to check your
understanding of the subject matter. By each question in parenthesis is the page number on which the answer tothat question can be found. This will help you in checking your answers.
These study questions are representative of the type which are on the certification examination. By readingthis manual and answering the study questions, you should be able to gain sufficient knowledge to pass theKansas Commercial Pesticide Applicators Certification and/or Recertification examination.
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Introduction
The control of pests in commoditystorage (farm and commercial) andfood plants (food manufacturing,processing and warehousing) requiresa high degree of professionalismcombined with experience andknowledge.
Pest management programs mustutilize combinations of techniquesthat are effective, economical andemphasize prevention of food productcontamination. These programs mustbe directed at immediate pest prob-lems; at preventing future infestationproblems; and must respond toroutine daily needs, yet be flexible tomeet emergency pest control situa-tions. Integrated pest management instored-product pest control tends toemphasize the non-chemical aspectsof pest control with the judicious useof pesticides.
Unsatisfactory control of pestsresults in contaminated products thatcan cause health, financial, legal andaesthetic problems. Financial lossescan result from (a) presence of live ordead insects in products and con-tainers; (b) presence of odors, web-bing and frass in products andcontainers; (c) loss in faith in thecompany by the consumer becauseof these conditions; and (d) direct lossin weight resulting from insect feeding.
Persons applying pesticides(chemical control measures) must beknowledgeable about the chemicals,application technique and pesticideregulations to avoid contaminationof foods and/or legal problemsresulting from misuse.
A variety of pests may be found instored commodities and food pro-cessing facilities, depending upongeographic location, physical natureof the facility, and the type of foodbeing processed.
Pests contaminate, damage and/ordestroy stored raw materials andprocessed foods and must be con-trolled to maintain the quality andquantity of products. The presence orevidence of pests may result in actionsby federal and state agencies includ-
ing seizure of products, fines and/orimprisonment of responsible parties.
A potential source of pests in foodproducts is the raw material(s) fromwhich the food is made. Not onlymay pests from this source be diffi-cult to remove from the raw material,but they also may infest the process-ing plant and equipment, as well asproducts in the plant, transportationvehicles or warehouse facilities.Contamination from pests in rawmaterials also may pass through theprocessing system into finished foodproducts.
Why ControlStored-Product Pests?
Control of stored-product pests isnecessary to prevent contamination/adulteration of human foods. Personsinvolved in commodity/food storage,handling and/or processing have theresponsibility to prevent food adul-teration. Failure to do so can result inhuman illness and/or death, theviolation of laws, loss of good willand resulting loss of revenue.
In recent years, regulations such asthose of the Food and Drug Adminis-tration (FDA), the EnvironmentalProtection Agency (EPA), and theFederal Grain Inspection Service(FGIS) of the U.S. Department ofAgriculture (USDA) have beenmodified to reflect an increasedemphasis on reducing the potentialfor pest adulteration of food products.
The Federal Food Drug andCosmetic Act defines a food asadulterated “if it contains any filthy,putrid or decomposed substance, orif it is otherwise unfit for food (Sec.402 (a) (3)), or if it has been prepared,packed, or held under unsanitaryconditions whereby it may have beencontaminated with filth or whereby itmay have been rendered injurious tohealth (Sec 402 (a) (4)).” The filthy,putrid or decomposed material maybe a result of insects, rodents, birds,or micro-organisms; otherwise unfitfor food may be the result of con-tamination by physical or chemicalcontamination, such as glass, metal,pesticides, etc.
As indicated in this introduction,the control of pests in commoditystorage and/or food processingfacilities requires a high degree ofprofessionalism combined withexperience and knowledge. Thefollowing sections of this manualprovide valuable information forapplying various pest managementpractices.
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Stored-Product
InsectsInsects are important pests of
cereal grains and stored food. Underoptimum conditions many of thespecies can complete their life cyclesin less than 30 to 35 days and laymany eggs. This results in rapidbuild-up of populations that con-sume and contaminate various storedproducts.
Most stored product insects areeither beetles or moths. Both havecomplete metamorphosis, i.e., theyhave four distinct developmentalstages: egg, larva, pupa and adult.The larval stage is “worm-like” or“grub-like” and differs in appearancefrom the adults. Often, people do notassociate the “worms” with theadults which produce them. Growthoccurs in the larval stage and aftertransformation to the adult there isno further growth in size. (Figure 1).
Beetles are characterized by ratherhard, shell-like bodies with theforewings modified into covers(elytra) which overlay the back of theinsect and protect the thin membra-nous flight wings (if present) foldedunderneath. The adults of most of thestored-product beetles live and feedin the same food materials as thelarvae. Both have chewing mouth-parts. A pictorial key (Figure 2)illustrates the differences in appear-ance of several species of stored-product beetles.
Moths that infest cereal grains andstored products are similar to“millers” and have scales coveringthe wings and bodies. The larvae arecaterpillars which do not resemblethe adults—they have chewingmouthparts while adults may havecoiled siphoning tubes suitable onlyfor liquid food. Since liquids areusually not available to them, adultsnormally do not feed. Therefore, themoths usually only live long enoughto mate and lay eggs.
How Stored-ProductInsects Multiply
Stored-product insects are smalland often not noticed unless carefullylooked for. Fifty rice weevils can beplaced on the surface of a penny.Stored-product beetles can survive inany part of a grain mass, in smallaccumulations of grain or grainproducts in storage or processingfacilities, and in “dead” areas inhandling or processing equipment.
Temperature and moisture contentof the food source play an important
Table 1. Number of offspring five months after 50 pairs of rice weevils wereplaced in wheat.
GRAIN GRAIN TEMPERATURE (˚F)MOISTURE 60˚ 70˚ 80˚ 90˚
9% 0 0 0 010% 0 0 326 41311% 40 87 885 98412% 58 4,827 9,661 2,22313% 514 8,692 10,267 3,23014% 951 10,745 13,551 3,934
Figure 1
PUPAStage lasts 5 to 15 days.
Exit hole of adult from wheat kernel.
Adults formed in 4 to 7 weeks aftereggs are laid. May remain inside kernelsfor severl days after being formed.
Adults may live 4 to 5 months.
3RD INSTARLARVA
2ND INSTARLARVA
1ST INSTARLARVA
LARVA
Usually only one larva per kernel.Two larvae may live in a singlekernel separated by the crease.
EGG
Egg laid in small cavity cut intokernel. Cavity filled and concealedwith gelatinous “egg-plug.” Eggshatch 5 to 15 days. Each femalemay lay 300 to 400 eggs.
RICE WEEVILSitophilus oryza (L.)
Rice Weevils are reddish-brown to black. They are 1/8 inch long. Two light spots are on each front wing. Body is cylindrical. Head is prolongedinto snout. Hind wings function as flight wings.
4TH INSTAR LARVA
Larva develops inside kernel. Larva is white,wrinkled and legless. Requires four molts and growthperiods
4TH INSTAR LARVALarva develops inside kernel. Larva iswhite, wrinkled and legless. Requires fourmolts and growth periods before trans-forming to adult. Stage lasts 15 to 40 days.
3RD INSTARLARVA
2ND INSTARLARVA
1ST INSTARLARVA
LARVAUsually only one larva per kernel.Two larvae may live in a singlekernel separated by the crease.
EGG
Egg laid in small cavity cut intokernel. Cavity filled and concealedwith gelatinous “egg-plug.” Eggshatch 5 to 15 days. Each femalemay lay 300 to 400 eggs.
RICE WEEVILSitophilus oryza (L.)
Adults may live 4 to 5 months.
Adults formed in 4 to 7 weeks after eggsare laid. May remain inside kernels forseveral days after being formed.
Exit hole of adult from wheat kernel.
PUPAStage lasts 5 to 15 days.
Rice Weevils are reddish-brown to black. They are 1/8 inch long. Two light spots are on each front wing. Bodyis cylindrical. Head is prolonged into snout. Hind wings function as flight wings.
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Pronotum with 6 teeth on each side. Beakabsent. Species about 1/8 inch long.
Pronotum without teeth on each side.Beak absent.
Pronotum without teeth on each side. Beakis present. Species is about 1/8 inch long.
Head back of eye rounded.Head back of eye pointed.
Each fore wing with 2 pale spots.Pronotum with round punctures.
Each fore wing dark.Pronotumwith elongate punctures.
Small brownish species. Lessthan 1/4 inch long.
Larger blackish species. 1/4 to3/4 inch long.
Male genital structurenot grooved.
Male genital structuregrooved.
GRANARY WEEVILSitophilus granarius
SAW-TOOTHED GRAINOryzaephilus surinamensis
MERCHANT GRAIN BEETLEOryzaephilus mercator
Head visible from above 1/8 inch long or more.
Antennal segments graduallyenlarge towards tip.
Antenna appears to beclubbed.
CONFUSED FLOURTribolium confusum
RED FLOUR BEETLETribolium castaneum
Fore wing withroughened surface.
Fore wing with lines. Fore wing is smooth. Flattened beetles 1/4 to 1/2 inch long.Pronotum is separated by strongconstriction from bases of wings.
Convex beetles 1/2 inch long ormore. Pronotum not so stronglyseparated from bases of wings.
LESSER GRAIN BORERRhyzopertha dominica
DRUG-STORE BEETLEStegobium paniceum
CIGARETTE BEETLELasioderma serricorne CADELLE
Tenebroideas mauritanicusYELLOW MEAL WORM
Tenebrio molitor
RICE WEEVILSitophilus oryzae
MAIZE WEEVILSitophilus zeamais
Head not visible from above 1/8 inch long or more.
Flattened beetles 1/4 to 1/2 inch long.Pronotum is separated by strongconstriction from bases of wings.
RICE WEEVILSitophilus oryzae
Stored-Product
Insectspart in the speed with which stored-product insect populations increase.Stored wheat frequently retainssummer heat so that temperatures insome parts of the grain mass remainsabove 15˚C (60˚F) until Octoberthrough January. In general, as grainmass temperatures increase above15˚ C (60˚F), stored-product insectscan survive and reproduce in grainof lower moisture contents. Similarly,high-moisture contents enablestored-product insects to survive atlower temperatures (See Tables 1 and2). Similar temperatures and mois-ture contents are favorable for stored-product insects in food storage andprocessing facilities.
Over extended periods, the upperlimits for survival and reproductionof stored-product insects, are approx-imately 38˚C (100˚F) and above
15 percent moisture content (mostlybecause molds and other micro-organisms take over at moisturelevels above this point). Lower limitsare 15˚C (60˚F) for reproduction and9 percent moisture content. Stored-product insects may survive byacclimation below 15˚C (60˚F) butgenerally die without reproducingduring extended periods below thistemperature. Many of the stored-product insects produce a newgeneration every month whentemperature and moisture conditionsare favorable.
Stored-product insects may befound wherever there are grain orgrain products. Sources of infestationon farms are seed grains, storedgrains, animal feeds or feeders, grainhandling equipment and smallaccumulations at various locations. Figure 2
Pronotum with 6 teeth on each side. Beakabsent. Species about 1/8 inch long.
Head back of eye rounded.Head back of eye pointed.
MERCHANT GRAIN BEETLEOryzaephilus mercator
SAW-TOOTHED GRAINOryzaephilus surinamensis
Head visible from above 1/8 inch long or more
Antennal segments graduallyenlarge towards tip.
Antenna appears to beclubbed.
Small brownish species.Less than 1/4 inch long.
Larger blackish species.1/4 to 3/4 inch long.
Pronotum without teeth on each side.Beak absent.
RED FLOUR BEETLETribolium castaneum
CONFUSED FLOURTribolium confusum
Fore wing withroughened surface.
Fore wing with lines. Fore wing is smooth.
LESSER GRAIN BORERRhyzopertha dominica
CIGARETTE BEETLELasioderma serricorne
DRUG-STORE BEETLEStegobium paniceum
Pronotum without teeth on each side. Beakis present. Species is about 1/8 inch long.
Each fore wing with 2 palespots. Pronotum with roundpunctures.
Each fore wing dark.Pronotum with elongatedpunctures.
GRANARY WEEVILSitophilus granarius
Male genital structurenot grooved
Male genital structuregrooved
MAIZE WEEVILSitophilus zeamais
CADELLETenebroides mauritanicus
Convex beetles 1/2 inch long ormore. Pronotum not so stronglyseparated from bases of wings.
YELLOW MEAL WORMTenebrio molitor
Head hidden under pronotumless than 1/8 inch long
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In grain elevators, receiving pits,bucket elevator boots, and deadspaces in other grain handlingequipment, as well as dust andspillage accumulations are commonsources. Food processing facilitiesalso provide a variety of potentialsources of infestation, including dead
moisture conditions within theequipment providing an idealenvironment for stored-productinsect development.
Internal GrainInfesting Insects
There are five species of insectsthat feed and develop internally inkernels of cereal grains. Because ofthe difficulty of removing theseinternal forms, they are responsiblefor most of the insect fragmentsfound in finished cereal foods, e.g.,flour, corn meal, etc. Remember,using fumigants to kill these internalforms will not eliminate the frag-ments in the processed product.
There are three species of weevils(insects with the head elongated intoa snout). They are very similar inappearance, behavior and develop-ment, but have some differences asoutlined in the following description(Figure 2):
Rice Weevil—Sitophilus oryzae (L.)■ Head is elongated into a snout,
at the end of which are strongteeth-like mandibles.
■ Adults are about 3 millimeters(1⁄8 inch) long, dark brown withtwo rather large, yellowishspots on each wing cover.
■ Pits on the pronotum (top ofprothorax, just behind head) arenearly round and are closetogether.
■ Usually found only in wholecereal grains (wheat, corn,sorghum, rice). Not a problemin flours, meals, etc.
■ Female chews a hole in thekernel, deposits an egg in it andseals the hole with a gelatinousmaterial.
■ The white, legless, grub-likelarva hatches from the egg aftera few days, feeds and completesdevelopment to adult inside thekernel. The adult chews its wayout of the kernel and continuesto feed on the grain.
■ The rice weevil may fly andinfest grain maturing in thefield in warmer areas of the U.S.
Stored-Product
Insects
spots in grain handling and process-ing equipment, screenings from graincleaning, and product accumulationsin cracks and crevices in the facilities.
The presence of grain dust, fines,broken kernels and other dockagepermits certain stored-productinsects to survive adverse tempera-ture and moisture conditions. Forinstance, confused flour beetles werenot able to maintain themselves inclean, low moisture (8 percent)wheat, but they at least maintainedtheir populations when dockage wasadded to the same grain. Clean grain,therefore, is an important factor incontrolling infestations.
Some stored-product insects, forexample the cadelle, can becomedormant and survive throughperiods of low temperatures and lowmoisture that exceed one year inlength. For these, thorough cleaningof storage structures followed byresidual insecticides is an importantstep in preventing infestation carry-over from one batch of grain to thesucceeding batch.
Grain processing facilities aregenerally heated during cold periodsof the year increasing the potentialfor stored-product insect develop-ment on a year-round basis. Inaddition, processing operations quiteoften generate heat and increased
Table 2. Effects of grain temperature on egg laying, development, andsurvivorship of the confused flour beetle.
Temperature(˚F) Eggs/Day Days to Hatch % Hatching
61 occasional — —63–64 1.2 39 27
72 1.9 14 7777 5.9 8.3 9081 7.5 6.2 9090 10.1 4.3 92
100+ All Components Decline
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■ Uniformly dark brown, about3 millimeters (1⁄8 inch) long.
■ Adults are strong fliers.■ Usually only infests whole
cereal grains. Eggs are placedamong the kernels (not inside).Newly hatched larvae burrowinto the kernels where theydevelop to the adult stage. Theadult chews its way out of thekernel, then continues to feedon grain.
■ During development the larvaepush “dust” out of the kernels.The dust has a sweetish, mustyodor and is composed of fecalmaterial and flour. Lesser grainborer infestations often can beidentified by this odor in thegrain storage.
■ Although usually found inwhole grain, they are capable ofcompleting development inflours, meals or broken kernels.
Stored-Product
Insects
Figure 3
PUPA
Damages grain by hollowing out insidesleaving only shells. Much loose flourproduced.
Emerge as adults 35 to 110 days after eggswere laid.
Larva usually develop inside of kernel.
Young larva start feeding on flour and thenbore into kernels where they complete theirlife cycle.
Eggs hatch 6 to 14 days.
Eggs dropped singly or inbatches into loose grain.
LESSER GRAIN BORERRhyzopertha dominica (F.)
Body is black to brown and cylindrical. 1/8 inch long. Head turned down under thorax. Adult armed with powerful jawsthat can cut into wood. Adult is a strong flier. Larvae and adults are both destructive.
GROWN LARVAGROWN LARVA
Larva usually develops inside of kernel.
Young larva start feeding on flourand then bore into kernels wherethey complete their life cycle.
Eggs hatch 6 to 14 days.
Eggs dropped singly or inbatches into loose grain.
Emerge as adults 35 to 110 days after eggswere laid.
Damages grain by hollowing outinsides leaving only shells. Muchloose flour produced.
■ Adults live four to five monthsand females lay 300 to 400 eggs.Complete life cycle may be asshort as 27 days but averagesabout 35 under favorableconditions.
Maize Weevil—Sitophilus zeamais(Motsch)
■ Appearance and habits of themaize weevil are so similar tothose of the rice weevil that it isunnecessary for most people todistinguish them. This insectusually is larger than the riceweevil but coloration andpronotal pits are similar. Thetwo species may be distin-guished by spatial arrangementof the pits and by differences inappearance of internal repro-ductive structures.
■ Although it can infest any of thecommon stored cereal grains, itis a stronger flier than the riceweevil and is the weevil speciesmost commonly found in cornin the field in the south. Itcontinues infestation in storage.
Granary Weevil—Sitophilusgranarius (L.)
■ Similar to the rice and maizeweevils but is a uniform colorand somewhat more shiny. Thepits on the pronotum areelliptical and not as closelyspaced as those of the abovetwo species. The adult issomewhat larger than the riceweevil usually, but similar insize to the maize weevil.
■ Does not fly so is dependentupon man for its distribution.
■ Infests whole cereal grains, onlyafter harvest.
■ Life cycle averages about 40 days;300 to 400 eggs per female.
■ Unlike the rice and maizeweevils, it has not been found ingrain maturing in the field.
Lesser Grain Borer (Figure 3)■ Small, cylindrical beetle with
the head pointed downwardfrom under the prothorax. Headusually cannot be seen fromabove.
PUPA
LESSER GRAIN BORERRhyzopertha dominica (F.)
Body is black to brown and cylindrical. 1/8 inch long. Head turned down under thorax. Adult armed withpowerful jaws that can cut into wood. Adult is a strong flier. Larvae and adults are both destructive.
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EGGSte. Laid on food in0. Hatch 2 to 14 days.
LARVALarvae (caterpillars usually yellowish, greenish or pinkish.Spin large amounts of silk over their food. Stage may last2 weeks up to 2 years. Larvae is the destructive stage.
PUPALarvae usually come to the food-mass to spin copupate. Stage may last 4
Adults formed 4 to 6 weggs laid. Adults dieoviposition.
Angoumois Grain Moth■ Adult is tan or buff color,
similar in appearance to clothesmoths and about 6.5 millimeters(1⁄4 inch) long. The hind winghas a fringe of long hairs andthe leading edge is extended atthe tip to form a “pointingfinger.”
■ Eggs are laid among kernels ofcereal grains. A few days laternewly-hatched larvae enter thekernels where development toadults is completed.
■ The mature larva prepares athin escape “window” for theadult by chewing away all but athin outer layer of the graincovering. These “windows” aremore conspicuous on cornkernels than on wheat.
■ Usually infests only wholecereal grains. In bulks of smallgrains and shelled corn, itinfests only the top few inches.In ear corn it may infest theentire bulk. It is not a problemin flours, meals, etc.
■ Adults do not feed. They liveonly a few days, lay 80 to100 eggs per female, andcomplete their life cycle in35 to 40 days.
Other Stored-Product(External) InsectsIndian Meal Moth (Figure 4)
■ Adult moth is about 10 millime-ters (3⁄8 inch) long and dark,except for a conspicuous lightband across the base of thewings (usually folded longitudi-nally over the back). When atrest, a distinctive dark-light-dark sequence is visible. Thedistal portion of the wings is adark “coppery” color.
■ Larvae are caterpillars that webfood particles together with silkand often wander out of thefood materials in search ofplaces to pupate.
■ Infest a variety of materialsincluding cereal products,meals, feed, dried fruit, nutsand whole cereal grains.
■ A common pest in grain bins. Itinfests just the upper few inchesof the grain mass but may be sonumerous that surfaces may becovered by a mat of silk web-bing. Early infestations areevidenced by several kernelswebbed together in clumps.
■ A common kitchen and ware-house pest.
■ Adults do not feed and livejust a few days. Females lay200 eggs each. Life cycle aver-ages 35 to 40 days.
Red Flour Beetle—Triboliumcastaneum Herbst
■ Adults are uniform reddish-brown, shiny, about 3 milli-meters (1⁄8 inch) long andsomewhat flattened.
■ Both adults and larvae feed in avariety of materials: flour, meals,nuts, dried fruits and wholegrain if moisture is sufficientand/or contains broken kernels.
■ Adults can fly.
Stored-Product
Insects
Figure 4
LARVALarvae (caterpillars usually yellowish, greenish orpinkish. Spin large amounts of silk over their food.Stage may last 2 weeks up to 2 years. Larvae is thedestructive stage.
EGGSWhitish and ovate. Laid on food inclusters of 12 to 30. Hatch 2 to 14 days.
PUPALarvae usually come to the outside ofthe food-mass to spin cocoons andpupate. Stage may last 4 to 30 days.
Adults formed 4 to 6 weeks aftereggs laid. Adults die afteroviposition.
INDIAN-MEAL MOTH(Plodia interpunctella Hbn.)
Basal half of front wings light colored; distal half dark. Hind wings lack distinctive markings and are more or lessuniformly gray. 1/2 to 3/4 inch wing spread.
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PUPANaked. At first it is white, but itgradually changes to yellow, thenbrown. Shortly afterwards ittransforms into an adult.
Stage lasts 1 to 2 weeks.
Change to adults 1 to 4months after eggs are laid.
When fully grown, they areabout 1/4 inch long. They arewhite, tinged with yellow. Stagelasts 2 weeks to 2 months.
Feed on flour or other materialsuch as grain dust and the brokensurfaces of grain kernels.
When hatched, larvae are worm-like, slender, cylindrical, andwiry in appearance.
EGGSEggs hatch in 5 to 12 days.
Eggs are small, clear, andsticky. They are laid on sacksor food, or in cracks.
LARVA
CONFUSED FLOUR BEETLETribolium confusum (Duv.)
Beetles elongate. They are shiny, reddish-brown and about 1/7 inch long. Head and upper parts of thorax are denselycovered with minute punctures and wing covers are ridged lenghtwise and sparsely punctured between the ridges. Theyresemble the Red Flour beetle.
Flat Grain Beetle (Figure 7)■ Adults are flat, reddish-brown
and among the smallest of thestored-grain insects (2 milli-meters or 1⁄12 inch long). Anten-nae are long and slender—thefemale’s about half as long asthe body and the male’s two-thirds as long. The prothorax ofthe female is nearly square; thatof the male narrows slightlytoward the posterior.
■ Both larvae and adults feed ingrain, cereal products, nuts andother stored products. Theymay infest deadstock in mills.
■ They are common in grain,often abundant in grain infestedwith other insects such as theweevils. They cannot developon completely sound kernels ofgrain, but nearly all masses ofgrain include damaged kernels.
Stored-Product
Insects
Figure 5
PUPANaked. At first it is white, butit gradually changes to yellow,then brown. Shortly afterwardsit transforms into an adult.
LARVAWhen fully grown, they areabout 1/16 inch long. They arewhite, tinged with yellow. Stagelasts 2 weeks to 2 months.
Feed on flour or other materialsuch as grain dust and the brokensurfaces of grain kernels.
When hatched, larvae are worm-like, slender, cylindrical, andwiry in appearance.
EGGSEggs hatch in 5 to 12 days.
■ Outer three antennal segmentsof the adult are similar in sizeand distinctly larger than theadjacent ones.
■ Adults live several months andlay 400 to 500 eggs per female.Complete life cycle averages35 to 40 days.
Confused Flour Beetle (Figure 5)■ Very similar in appearance and
behavior to red flour beetles.■ Antennal segments enlarge
gradually toward the tip of theantenna.
■ Do not fly.■ Probably the most common
flour mill insect, although it caninfest the same foods as the redflour beetle.
Saw-toothed Grain Beetle (Figure 6)■ Adults are slender, flat, dark
brown and about 2.5 milli-meters (1⁄10 inch) long. Each sideof the prothorax (just behindhead) bears 6 pointed, saw-tooth-like projections.
■ Both larvae and adults feed incereal products, nuts, driedfruits, meals and whole cerealgrains.
■ This species is a commonkitchen and warehouse pest andone of the most common insectsin Kansas farm-stored grain(although not as damaging asinternal feeders).
■ Small size, especially of newly-hatched larvae, permits penetra-tion of all but the tightest foodpackages.
■ Adults live several months andlay up to 300 eggs per female.The life cycle may be completedin 25 days but the average islonger.
Merchant Grain Beetle—Oryzaephilus mercator (Fauv.)
■ Almost identical in appearanceand habits to the saw-toothedgrain beetle.
■ Infests the same foods as thesaw-toothed grain beetle, but isbetter adapted to oilseeds andoilseed products than theformer.
Eggs are small, clear, andsticky. They are laid onsacks or food, or in cracks.
Stage lasts 1 to 2 weeks.
Change to adults 1 to 4months after eggs are laid.
CONFUSED FLOUR BEETLETribolium confusum (Duv.)
Beetles elongate. They are shiny, reddish-brown and about 1/7 inch long. Head and upper parts of thorax aredensely covered with minute punctures and wing covers are ridged lengthwise and sparsely punctured between theridges. They resemble the Red Flour Beetle.
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PUPAStage lasts 6 to 21 day
Emerge as adults in as short a timeas 24 to 30 days under favorableconditions. May be 4 generationsper year.
Larvae become full-grown in 2 to10 weeks when they are about 1/8inch long.
e slender, brown-headed,six-legged.
h in 3 to 7 days.
gs are laid in cracks and crevicesor near food. Each female can lay to 300 eggs in her lifetime.
LARVAThis stage lasts 2 to 10 weeks.
SAW-TOOTHED GRAIN BEETLEOryzaephilus surinamensis (L.)
Slender and flat beetles 1/10 of an inch long. Color ranges from dark-brown to red. Sides of thorax have sixsaw-toothed projections. Adults almost never fly. Adults have been kept alive for over 3 years.
PUPAStage lasts 6 to 21 days.
Stored-Product
Insects
Figure 6
Figure 7
LARVAThis stage lasts 2 to 10 weeks.
Emerge as adults in as short atime as 24 to 30 days underfavorable conditions. May be 4generations per year.
Larvae become full-grown in 2 to10 weeks when they are about 1/8inch long.
Larvae are slender, brown-headed,white, and six-legged.
Eggs hatch in 3 to 7 days.
Eggs are laid in cracks and creviceson or near food. Each female can lay50 to 300 eggs in her lifetime.
y 200 eggs.
LARVA
PUPAWhen fully grown, larvae foof a gelatinous substance toparticles adhere. Pupae are fof these cocoons.
Adult emerges 5 to 9 wafter eggs are laid.
white. Eggs are placedrain or dropped looselyreal products.
m of wheat. Also
e are slender, pale in black head. They havek, spine-like processes ate abdomen.
PUPAWhen fully grown, larvae formcocoons of a gelatinous substance towhich food particles adhere. Pupaeare formed inside of these cocoons.
Adult emerges 5 to 9 weeksafter eggs are laid.
LARVA
Grown larvae are slender, pale incolor, with a black head. They haveslender, black, spine-like processesat the tip of the abdomen.
Larvae fond of the germ of wheat.Also feed on dead insects.
Each female can lay 200 eggs.
Eggs are small and white. Eggs are placedin crevices on the grain or dropped looselyin flour or other cereal products.
FLAT GRAIN BEETLE(Cryptolestes pusillus (Schonh.))
Beetles and larvae of this species resemble those of the Rusty Grain Beetle so much in behavior and appearancethat distinction is rarely made between them by people in the grain industry. They are the smallest of the majorgrain pests (1/16 inch long). Beetles are reddish-brown with a flattened body. Males have an especially long,slender antennae.
11
PUPAPupation usually occurs on the top of food material. Stays in pupal stagaverage of 6 days at 90°F.
Adults usually mate immediately oemergence. Egg laying starts severallater. Adult has not been observed t
Adult may live only a few days or clive up to several days. Entire cycleto adult) varies from 4 to 6 weeks toseveral years.
rvae grow older, they feed on whole or seeds. Are very resistant toation, may live for months or even without food.
n damaged by Khapra beetles has the appearance as grain attacked by ther grain borer.
g larvae feed largely on damagedls. They are about 1/16th inch long.
EGGfemale lays up to 126 eggs. Eggsin 8 days at 90°F.
LARVALarvae are about 1/6th inch long. Have typical cream and tancoloring of Trogoderma larvae. Older larvae are repelled bylight. A typical infestation is characterized by large numbersof larvae and their cast skins. Stage lasts 27 days at 90°F. (Maystay in larval stage for years.)
Stored-Product
Insects■ Larvae feed principally on the
germ of kernels.■ Each female may lay 200 to
300 eggs.■ Their life cycle may be com-
pleted in as few as 22 days, butis somewhat longer.
Rusty Grain Beetle—Cryptolestesferrugineus (Steph.)
■ Similar to the flat grain beetle,except that antennae of malesand females are the samelength, about half the length ofthe body.
■ The prothorax is slightly longerthan broad and tapers towardthe posterior. This is morepronounced in the male.
■ Habitats and biology are similarto those of the flat grain beetle.
■ Both species are common inKansas stored grain. No doubtrusty grain beetles have oftenbeen reported as “flat grainbeetles.”
Dermestid BeetlesGrain Dermestids (Trogodermaspecies)
■ Dark, oval beetles, from 2 to3 millimeters (1⁄12 to 1⁄8 inch) inlength, with hairs on the wingcovers (may be rubbed off, thenbeetle appears shiny) and ratherindistinct patterns of brown andblack. Females are larger thanmales.
■ Larvae have long hairs andthick tufts of smaller brownhairs on a few of the posteriorsegments and have a “ringed”appearance. The width of thebody is nearly uniform through-out its length.
■ Infestations are revealed by cast“skins” of the larvae, which areshed at each molt, and may benumerous on the surface of thefood material, sacks andpackages.
■ They infest many kinds ofcereal products, meals andsometimes grain.
■ Adults do not feed in the samefood materials as larvae and areshort-lived, so are not as readily
observed in infested foods aslarvae.
■ The life cycle may be completedin 25 to 35 days, but often islonger.
■ Larvae are capable of livingmore than a year without food.
■ Khapra beetle is illustrated(Figure 8). Sporadic accidentalimportations into the U.S. haveoccurred in the past few yearsbut vigorous inspections andquarantines have preventedlong-term establishment of thisserious pest.
Black Carpet Beetle—Attagenuspiceus (Oliv.)
■ Adults are similar in appear-ance to the Trogoderma speciesbut usually larger and uni-formly black or dark brown.Length is about 3 to 5 milli-meters (1⁄8 to 3⁄16 inch). Figure 8
LARVALarvae are about 1/6th inch long. Have typical cream andtan coloring of Trogoderma larvae. Older larvae arerepelled by light. A typical infestation is characterized bylarge numbers of larvae and their cast skins. Stage lasts27 days at 90˚F (May stay in larval stage for years.)
As larvae grow older, they feed on wholegrain or seeds. Are very resistant tostarvation, may live for months or evenyears without food.
Grain damaged by Khapra beetles has thesame appearance as grain attacked by theLesser Grain Borer.
Young larvae feed largely on damagedkernels. They are about 1/16th inch long.
EGGAdult female lays up to 126 eggs. Eggshatch in 8 days at 90˚F.
PUPAPupation usually occurs on the top layerof food material. Stays in pupal stage anaverage of 6 days at 90˚F.
Adults usually mate immediately onemergence. Egg laying starts several dayslater. Adult has not been observed to fly.
Adult may live only a few days or can liveup to several days. Entire cycle (egg toadult) varies from 4 to 6 weeks to severalyears.
KHAPRA BEETLETrogoderma granarium (Everts)
One of the most important cosmopolitan pests of stored grain. First discovered in the U.S. in Calif. in 1953.Thought to have been present since 1946. Adult is small (1/14th to 1/8th inch in length); females are often twicethe size of the males. Beetle is pale red-brown to dark brown or black; wing covers unicolorous or with indistinctred-brown markings. Hairs on top often rubbed off, giving the beetle a slick appearance. Khapra beetle hard todistinguish from other species in its group.
12
Stored-Product
Insects■ The larvae are darker than
Trogoderma larvae and have aparticularly long tuft of hairs atthe posterior end. The bodynarrows from front to backwhich gives it sort of a cigarshape. It has a “ringed” appear-ance, as do the cast “skins”which are found on the surfaceof the food medium or in folds,cracks or crevices in sacks,packages, walls, etc.
■ Infestations may occur in manyof the cereal products and grainas well as in carpets, woolens, etc.
Cigarette Beetle (Figure 9)■ Small, reddish brown, oval,
hump-backed beetle about2.5 millimeters (1⁄10 inch) long. Itis covered with fine hairs and
the head points downwardunder the hood-like pronotum.There are no striations (grooves)on the wing covers. Antennaeare rather long and slender withsegments resembling saw teeth.
■ Larvae are white and grub-likewith long hairs.
■ Have been found infesting awide range of materials such astobacco, spices, nuts, grain,dried fish and meatmeal.
■ Adults feed little, if at all, andlive only a few days. Femalesaverage 100 eggs each andcomplete life cycle in about35 days.
Drugstore Beetle—Stegobriumpaniceum (L.)
■ Similar to the cigarette beetle,but less oval with striations onwing covers and with a lesshump-backed appearance. Theouter three segments of theantennae are distinctly enlarged.
■ Although there are minordifferences in larval appearanceand habits, they are not consid-ered here.
■ This insect lays fewer eggs(75 per female) and has a slightlylonger life cycle (40 days) thanthe cigarette beetle.
Cadelle (Figure 10)■ Adult is a flattened, black, shiny
beetle about 8 millimeters(1⁄3 inch) in length. The head andprothorax are closely joined butappear separate from the rest ofthe body giving the body adivided appearance.
■ The larva is white with blackhead and conspicuous blackplates on the first segmentbehind the head and at the tipof the abdomen, the latterbearing two horns.
■ In grain, especially in woodenstructures, both larvae andadults burrow into the wood topupate in cold weather or whenno grain is in the bin.
■ Both larvae and adults feed ongrain, flour and other grainproducts.
Figure 9
Full-grown larve about 3/16 inch long. Fine hairson body appear light brown on mature larvae.
Pupal stage lasts 7 to 18 daysdepending on weather.
Total life cycle (egg to egg) takes56 days in summer.
arvae mature in 30 to 50 days.
hatched larvae are tiny.rayish white and coveredh fine hairs.
in 6 to 10 days.
pearly white, elongate,t 1/50 inch in length. Haveells that are resistant toAre fragile.
During a 3 to 4 week lifetime,each female may lay 75 to 100eggs. Most eggs laid during first10 days.
Full-grown larvae about 3/16 inch long.Fine hairs on body appear light brown onmature larvae.
Larvae mature in 30 to 50 days.
The newly hatched larvae are tiny. Theyare grayish white and covered thinly withfine hairs.
Eggs hatch in 6 to 10 days.
Eggs are pearly white, elongate, and about1/50 inch in length. Have waxy shells thatare resistant to drying. Are fragile.
During a 3 to 4 week lifetime,each female may lay 75 to 100eggs. Most eggs laid during first10 days.
Pupal stage lasts 7 to 18 daysdepending on weather.
Total life cycle (egg to egg) takes56 days in summer.
THE CIGARETTE BEETLELasioderma Serricorne (F.)
The adult cigarette beetle is brown and less than 1/8 inch long. It is cosmopolitan in distribution, having been carriedaround the world by commerce. Practically all injury to tobacco and many other stored products is caused by thefeeding of the larvae. It is found occasionally attacking grains left long in storage in original sacks.
13
Prepupal stage lasts 7 to 17 days.stage lasts 8 to 25 days dependinconditions, especially temperatur
Adults may live up to 2 years.
lete development in 2 to 14ally molt 3 or 4 times; mayif larval period is long.
days in warm weather.
id in clusters in the food
y about 1,000 eggs during
Grown larvae characterized by black heads and blackforked tail pieces. Transform to pupae, usually in achamber they have cut in the wooden surfaces of thestorage structure.
Stored-Product
Insects■ The female lays about 1,000
eggs and the life cycle is com-pleted in a minimum of 70 days.
Yellow Mealworm—Tenebriomolitor L.
■ Adults are shiny black or darkbrown and 14 to 20 millimeters(1⁄2 to 2⁄3 inch) in length. Thesebeetles are the largest found instored products.
■ The larvae are honey-yellowand attain a length of 26 to30 millimeters (1 to 11⁄4 inches).The body is heavily sclerotizedand cylindrical and is similar inappearance to wireworms.
■ They feed on grain and grainproducts, especially when it isout of condition. They may alsoinfest meals, meatmeal, millsweepings and other products.
Dark Mealworm—Tenebrioobscurus (F.)
■ Similar in size, appearance andhabits to the yellow mealworm,except the adults are dull andpitchy black, not shiny.
■ Larvae are much darker thanthe larvae of the yellowmealworm.
Insects Associated With HighMoisture Conditions
There are several other smallbeetles, i.e. the foreign grain beetle(Ahasverus advena Waltl), the hairyfungus beetle (Typhea stercorea (L.)),etc. which may be found in grain andgrain products slightly high inmoisture content. These insectsprimarily feed on fungi developing inthese products and do not signifi-cantly damage the products.
Booklice (Liposceles spp.) and mites(Acarious spp.) (not true insects butclose relatives) are microscopic insize and can be found under similarconditions (Figure 11).
Parasites and PredatorsOn occasion, very tiny insects
(some wasp-like) may be found inlarge numbers associated withinfested grains. These are naturalenemies (parasites/predators) of thegrain infesting insects. In someinstances, application of ineffectivechemical treatments may destroy theparasites/predators allowing thedamaging species to survive. Figure 10
Grown larvae characterized by black heads and blackforked tail pieces. Transform to pupae, usually in achamber they have cut in the wooden surfaces of thestorage structure.
Larvae complete the development in 2 to14 months. Usually molt 3 or 4 times;may have up to 7 if larval period is long.
Hatch 7 to 10 days in warm weather.
White eggs laid in clusters in the foodmaterial.
Females lay about 1,000 eggs duringlifetime.
Prepupal stages lasts 7 to 17 days. Pupalstage lasts 8 to 25 days depending onconditions, especially temperature.
Adults may live up to 2 years.
CADELLETenebroides mauritanicus (L.)
An elongated, oblong, and flattened beetle with a shiny-black or dark-brown body. It is one of the bestknown, most destructive, largest (about 1/3 inch long), and longest lived insects that attack stored grain.
14
Stored-Product
Insects
BooklouseLiposceles
MiteAcarious
Figure 11
Questions
1. (3) In recent years, regulations bywhat Federal government agencyhas increased emphasis onreducing pest adulteration offood products?a. Health and Human Services
(HHS)b. Centers for Disease Control
(CDC)c. Food and Drug
Administration (FDA)d. Bureau of Alcohol, Tobacco
and Firearms (BATF)
2. (4) Adult beetles infesting storedproducts are characterized by:a. rather hard shell-like bodiesb. soft, very fragile bodiesc. transparent body wallsd. body covered with scales and
hairs
3. (5) In general, stored grain masstemperatures above ___ allowinsects to survive in lowermoisture content.a. 30˚Fb. 40˚Fc. 50˚Fd. 60˚F
4. (6) The cadelle can becomedormant and survive low tem-perature and moisture conditionsfor over:a. 6 monthsb. 12 monthsc. 18 monthsd. 24 months
5. (7) This stored grain infestingweevil does not fly.a. Maize weevilb. Granary weevilc. Rice weevild. Lesser grain weevil
6. (8) Larvae of the ___ web foodparticles together.a. Rice weevilb. Angoumois grain mothc. Granary weevild. Indian meal moth
7. (9) One of the most commoninsects in Kansas farm-storedgrain is the ___.a. Saw-toothed grain beetleb. Rice weevilc. Angoumois grain mothd. Pea weevil
8. (11) Vigorous inspections andquarantines have prevented long-term infestations of this pest.a. Rusty grain beetleb. Merchant grain beetlec. Flat grain beetled. Khapra beetle
9. (12) The Drugstore beetle issimilar in appearance to:a. Yellow mealwormb. Cigarette beetlec. Dark mealwormd. Khapra beetle
10. (13) Ineffective chemical treat-ments may destroy these insectsand thereby allow the damagingspecies to survive.a. Syrphid fliesb. Parasitesc. Indian meal mothd. Merchant grain beetle
15
Monitoring for
Stored-Product
InsectsStored-product insects cause
significant losses of stored grains,processed foods, fibers and animalproducts. In general, losses can beminimized when infestations arequickly identified and appropriatecontrol measures implemented.
Numerous methods for detectingstored-product insects have beendeveloped or are being investigated.The most promising technique thathas been developed, and continues tobe refined, is monitoring populationswith insect pheromones and/or foodattractants.
The incorporation of monitoringmethods into existing stored-productpest management programs can leadto earlier detection of low levelinfestations and pinpointing locationof infestations. Monitoring informa-tion can be used to justify reductionin pesticide use or the need forintensified surveillance and pestmanagement procedures. Monitoringresults also can serve as an indicatorof how well integrated pest manage-ment (IPM) program components arefunctioning.
Monitoring MethodsCurrent monitoring methods for
insect infestation vary and depend onthe type of insect, commodity and/orstorage. They include:
Bulk Commodity Storage■ Observation of the commodity
surface and overspace forinsects and/or evidence of theirpresence, i.e. webbing,castskins, dust, odor, etc.
■ Examination of commoditysamples obtained by variousmeans, i.e. probe sampling,turning of the commodity, etc.
■ Probe (pitfall) traps insertedinto the surface of grain massesand left for varying lengths oftime have proven useful as ameans of early detection of live,free-living insects.
■ Temperature monitoring ingrain masses may detect
localized increases in tempera-ture which can indicate thepresence of an insect infestation.
Warehouse Storage ofProcessed CommoditiesPheromone/food attractantmonitoring
Pheromones have been identifiedfor many of the stored-productinsects. Some synthesized lures havebeen commercially developed and avariety of trap designs are available.Traps have been very effective formonitoring commodities that havefew species of stored-product pests,e.g., tobacco. Pheromone/foodattractant monitoring has theadvantage of:
■ continuous surveillance.■ targeting a defined area of
facility.■ identification of an infested area.■ early detection of an infestation.■ reduced need for time consum-
ing product inspection.■ providing a basis for minimum
pesticide application.Some definitions:■ Food attractant—A natural
food, food extract, or synthe-sized scent that will attract aselect group of insects. In somecases it is impregnated into anartificial medium.
■ Lure—A small rubber or plasticdevice impregnated with orretaining a pheromone or foodattractant, designed to releasethe attractant gradually over adesignated period of time,either passively or controlled.
■ Pheromone—A chemicalcompound produced by anorganism that initiates a behav-ioral activity in others of thesame species. Such compoundsare synthesized for attractingtarget insect species.
■ Aggregation pheromone—A communication chemicalpredominantly produced bymales that attracts both sexes.Effective compounds have beensynthesized for stored-product
16
Monitoring for
Stored-Product
Insects
insect species with long-livedadults (e.g. Tribolium,Rhyzopertha) and specieswhich need to feed toreproduce.
■ Sex attractant pheromone—A communication chemicalusually produced by females toattract the opposite sex. Effec-tive compounds have beensynthesized for stored-productinsect species with short-livedadults and adults that do notneed to feed to reproduce (e.g.,Plodia, Ephestia).
Pheromone and foodattractant lures (Table 3)
Pheromone lures have beendeveloped for several stored-productinsects. Lures developed for specieswith short-lived adults have provenmore effective. The lure for the lessergrain borer (Rhyzopertha dominica)also has produced good results. Foodattractant lures for stored-productinsects (predominantly an oil lureconsisting of oat oil, wheat germ oilextracts and mineral oil) are used forspecies having long-lived adults andsome larvae. These lures may be used
Table 3. Status of pheromones for stored-product insects.Codes: A = aggregation pheromone, F = food attractant, S = sex pheromone
Duration of Lure Comm. DurationGenus Adult Stage Type Available of Lure Effectiveness
Anagasta1 1–2 wks S Y 6–20 wks2 moderate–good(Mediterranean flour moth)
Anthrenus 2–4 wks S&F Y3 4–8 wks good(carpet beetle)
Attagenus 2–9 wks S&F Y3 4–8 wks good(black carpet beetle)
Cadra1 (Raisin moth) 1–2 wks S Y 6–16 wks2 moderate
Cryptolestes 3 mon–1 yr A N unknown N/A(flat grain beetle)
Ephestia1 1–2 wks S Y 6–20 wks2 moderate–goodAlmond/Tobacco moth)
Lasioderma 2–4 wks S Y 6–8 wks moderate–good(Cigarette beetle)
Oryzaephilus 6 mon–3 yr A/F4 N/Y unknown poor5
(sawtoothed grain beetle)
Plodia1 1–3 wks S Y 6–20 wks2 good(Indianmeal moth)
Rhyzopertha 6 mon A Y 8 wks good(Lesser grain borer)
Stegobium 2–5 wks S Y 4 wks unknown(Drugstore beetle)
Tribolium (flour beetle) 6 mon–3 yr A&F Y 7–16 wks variable (poor–good)
Trogoderma 2–4 wks S&F Y 6–26 wks good(warehouse/Khapra beetle)1 Same lure for all species, separate lure for Cadra under development.2 May be effective for up to 40 weeks based on USDA studies.3 Trogoderma traps utilizing food attractants will catch larvae of both Attagenus and Anthrenus. Commercial sex lures
have been marketed (1992) for carpet beetles, their effectiveness is not known.4 Aggregation pheromone under development.5 Food lure results have been erratic. Glue boards currently are almost as effective and more economical.Used with permission: Stored-product Pest Monitoring Methods. Technical Information Memorandum No. 27 ArmedForces Pest Management Board, June 1992.
17
with or without pheromones. Ingeneral, food attractant lures have asmaller effective range than phero-mone lures. They can be used toenhance the effectiveness of phero-mone traps for flour beetles(Tribolium) and to attractTrogoderma, Attagenus, andAnthrenus larvae.
Pheromone and foodattractant traps
There are a variety of traps used todeploy pheromones and/or foodattractants. Bulk grain is mosteffectively monitored with perforatedplastic probe (pitfall) traps. Traps areusually placed in the grain near thesurface at cardinal points and in thecenter. They take advantage of thenormal movement and activity ofgrain-infesting insects and mayinclude a pheromone or food attrac-tant lure.
Traps for flying insects (wing-,delta-, and diamond-traps) sus-pended at various locations through-
out grain elevators or warehouses arean effective way to monitor for mothadults and certain beetles. Lurescontaining pheromones for eitherIndianmeal moth or lesser grainborer placed in the center of a gluecoated surface within the trap attractsthese species and traps them on thesticky surface.
Multi-layered, corrugated papertraps with pheromones and/or foodattractants are used to monitor forbeetles and some larvae in ware-house situations. The corrugationsattract the insects by serving asharborage sites similar to crevices infloors and walls. Multiple entrypoints formed by the corrugationsprovide tactile stimuli and air cham-bers within the trap to providecirculation for the pheromones and/or food attractants. Traps usually lieflat to prevent spillage of foodattractant, however, some may bewall-mounted. A modified pitfalltrap for floor or shelf placement alsohas been designed.
Monitoring for
Stored-Product
Insects
18
Monitoring for
Stored-Product
Insects
Questions
1. (15) One of the promising tech-niques for stored products insectpest management is:a. Monitoringb. Poison baitsc. Spraying bin wallsd. Super cooling with CO2
2. (15) Monitoring of bulk commod-ity storage for insects mayinclude such techniques as:a. Observation of surface and
overspaceb. Probe traps inserted into the
surfacec. Temperature read-outs in the
grain massd. All the above
3. (15) These pheromones are usedin warehouse storage of pro-cessed commodities and theyattract both sexes of the species.a. Repellingb. Sexc. Aggregationd. Reproduction
4. (17) Pheromone and food attrac-tant traps may include:a. Perforated plastic probesb. Multi-layered corrugated
paperc. Wing-, delta-, and diamond
trapsd. All the above
19
CockroachesCockroaches are among the oldest
of insects, as indicated by fossilremains, dating to 200 million yearsago. This ability to survive the manychanging environments through timeillustrates the capability of theseinsects to adapt to wide ranges ofhabitats and living conditions.
Cockroaches may be direct carriersof disease. They also contaminatefood and kitchen utensils withexcrement and salivary secretionsand leave an unpleasant odor.Cockroaches sometimes produceallergic reactions in humans. Theallergy is due to cockroach parts(proteins), not the odor.
Biology and BehaviorCockroaches develop by gradual
metamorphosis through three lifestages: egg, nymph and adult. Adultfemales produce small, bean-likecapsules or oothecae which containthe eggs. These capsules usually aredropped at random near food orglued to some surface by the femalesoon after they are formed. (Thefemale German cockroach carries thecapsule protruding from her bodyuntil the eggs are ready to hatch.)
Nymphs which hatch from theeggs and emerge from the oothecaresemble adult cockroaches, exceptthat they are smaller and do not havefully developed wings. Their flat-tened bodies allow them to squeezeinto crevices and long, spiny legsenable them to run rapidly.
Nymphs molt several times beforebecoming mature males and females.As indicated in Table 4, the timerequired to complete the life cyclevaries from about 2 months to nearly3 years, depending on the speciesand environmental conditions. Mostcockroaches are tropical or sub-tropical in origin and generally liveoutdoors. However, some specieshave become well-adapted to livingwith humans. Though it is true thatcockroaches prefer poor housekeep-ing, they at times, infest even the
most sanitary and well-organizedbuildings.
Cockroaches can enter buildings inboxes and containers of all kinds.They also can enter around loose-fitting doors and windows, whereelectrical lines or water and streampipes pass through walls, sometimeseven in seasoned firewood andthrough sewer lines.
Most cockroaches are nocturnaland appear during daylight onlywhen disturbed or where there is alarge population. They prefer warm,dark, moist shelters and often arefound around food-handling areas;where pipes or electrical wiring passalong or through a wall; behindwindow or door frames, loosebaseboards or molding strips; orunderside of tables, chairs andequipment.
Cockroaches feed on a variety ofplant and animal products, includingmeat and grease, starchy foods,sweets, baked goods and otherunprotected kitchen goods. They alsofeed on materials such as leather,wallpaper paste and book bindingand sizing.
Common SpeciesThere are about 55 species of
cockroaches in the United States, butonly five species are routine prob-lems in buildings. Most of the otherspecies live outdoors and, therefore,escape notice; if brought into thebuilding they either leave or die.Unfortunately, four species ofcockroaches favor the buildings ofpeople as a home—reflecting theclose relationship humans have hadwith cockroaches since moving intothe first cave (Figure 12).
German Cockroach—Blattagermanica (L.)
■ Light brown and 13 to 16millimeters (1⁄2 to 5⁄8 inch) long.
■ The head shield is marked withtwo dark stripes that runlengthwise.
■ Adults are fully winged butrarely fly.
■ Immature German cockroachesare smaller and darker thanadults and are wingless.
Cockroaches
Figure 12
German Cockroach
American Cockroach
Brownbanded Cockroach
Oriental Cockroach
20
■ The most prevalent householdcockroach in Kansas and ismore active than other domesticspecies.
■ Troublesome infestations candevelop rapidly after the intro-duction of a few individuals.
■ The only domestic species inwhich adult females carry theegg capsules protruding fromtheir abdomens until the eggsare ready to hatch.
■ These cockroaches thrive in alltypes of buildings but are foundmost often in homes andcommercial food establishments.
■ Usually enter homes withbottled drinks, potatoes, onions,dried pet food, grocery sacks,corrugated cartons and evenfurniture.
■ Usually seek dark shelters nearmoisture and food. However,they may sometimes be foundin other parts of the building.
American Cockroach—Periplanetaamericana (L.)
■ Largest of the common species,growing to a length of 38 to51 millimeters (11⁄2 to 2 inches).Reddish-brown with a lightyellow band around the edge ofthe head shield.
■ Adults of both sexes have well-developed wings but seldomfly. However, they are capableof gliding flights.
■ Nymphal cockroaches aresmall, brown and not fullywinged.
■ Female usually drops her eggcapsule within a day after it isformed. The capsule often isdropped near a food source orin locations where it can becovered with miscellaneousdebris. Occasionally, the capsuleis glued to some surface withsecretions from the female’smouth.
■ They thrive in commercialestablishments and otherbuildings which providefavorable shelter and an amplefood supply. They live mainlyin dark, moist sites in base-ments, steam tunnels andsewers.
Brownbanded Cockroach—Supellalongipala (F.)
■ Light gold to glossy dark brownand 13 to 16 millimeters (1⁄2 to5⁄8 inch) long with transverseyellow bands across the base ofthe wings and across theabdomen.
■ Wings of adult males cover theabdomen while the female’swings are shorter.
■ Yellow bands are more pro-nounced on nymphs than onadults.
■ These cockroaches are quiteactive. Adult males fly readilywhen disturbed.
■ Female carries her egg capsulefor only a day or two beforegluing it to protected surfacessuch as the undersides offurniture and equipment and
Cockroaches
Ave
rage
nu
mbe
r of
eggs
per
cap
sule
Ave
rage
nu
mbe
r of
cap
sule
s p
rod
uce
d p
erfe
mal
e
Ave
rage
long
evit
y of
adu
lts
(day
s)
Len
gth
of L
ife
cycl
e(d
ays)
Ap
pro
xim
ate
num
ber
offs
pri
ng p
ossi
ble
per
yea
rbe
ginn
ing
wit
h on
e fe
mal
e
Table 4. Life-history of four common cockroaches in Kansas.
German 37 7 60–250 140 35,300
American 15 58 320–1070 440 810
Brownbanded 16 10 140–380 110 680
Oriental 14 14 210–990 100 200
21
sometimes to ceilings in dark-ened rooms.
■ Egg capsule remains in placeuntil hatching which mayrequire several weeks.
■ Brownbanded cockroaches aremore likely to be found inhomes, apartments, hotels,motels, nursing homes andhospitals than in restaurants,grocery stores and other com-mercial establishments.
■ Prefer starchy foods and appearto have lower water require-ments than other cockroaches.
■ Nymphs and adults are fre-quently found on ceilings,behind picture frames, in lightswitches, in upper walls ofcabinets and closets, on under-sides of furniture and insideupholstered furniture.
Oriental Cockroach—Blattaorientalus L.
■ Glossy dark brown to black.■ Females are nearly 38 milli-
meters (11⁄2 inches) long.■ Male has wings which cover
part of the body. Female hasrudimentary wings which arereduced to mere lobes.
■ Neither sex can fly; in fact, bothare rather sluggish.
■ Nymphs are dark brown toblack and have wing stubswhich lack a definite venation.
■ Female usually carries eggcapsule for about a day, then itis dropped or attached to aprotected surface near a foodsupply.
■ Adults are more abundant inthe spring.
■ Nymphs and adults usuallyfound near decaying organicmatter.
■ During warm, humid weatherthey inhabit lawns, compostpiles, flower beds and dumps.
■ In periods of drought or coolweather, there is mass move-ment into buildings.
■ In buildings, they inhabit highmoisture areas such as sewers,crawl spaces, drains, basements
and hollow spaces underconcrete slabs.
■ Activities restricted to theground or below-ground levelsin buildings.
Pennsylvania Wood Roach■ Not a normal building dwelling
species; but males are attractedto lights and will invade build-ings in the spring.
■ In wooded areas, the Pennsyl-vania wood roach is a definite,but usually seasonal problem.
Cockroach ControlThe control of cockroaches requires
much care and planning. Takingprecautions to prevent the invasionof cockroaches into a building worksbetter than applying insecticides tocontrol an established population.Cleanliness and elimination offavorable breeding sites will greatlylessen the possibility of cockroachinfestation, but these practices willnot always prevent infestation fromoutside. Cockroaches can survive ineven the most sanitary environmentonce an infestation is established.
Because various combinations ofcockroaches can occur in the samebuilding, it is essential to accuratelyidentify the species present. This willpermit use of control measures thattake advantage of behavioral patternsand life requirements for the particu-lar species. For instance, for chemicalcontrol of the widely dispersedbrownbanded cockroach, chemicalsmust be applied over greater areasof a building than for control of themore restricted oriental or Americancockroaches.
Non-chemical ControlNon-chemical measures include:
1. Keeping tight-fitting windowsand doors; caulking cracksin outside walls, sills andfoundations.
2. Sealing all openings whereelectrical lines or water, steamand cooling pipes pass throughwalls and floors to slow themovement of cockroaches intoa building.
Cockroaches
22
3. Inspecting boxes and othercontainers to avoid bringingcockroaches into the building.
4. Repairing plumbing leaks andsealing other moisture sources.
5. Keeping the premises clean byremoving all food crumbs andplacing garbage and trash intocontainers with tight-fitting lids.
6. Use roach traps (sticky traps) tomonitor for cockroach activity.
Chemical ControlTo effectively control cockroaches
with insecticides, it is necessary toinspect closely for their shelters andthoroughly treat these locations.Regardless of the insecticide orformulation chosen, chemicals placedin or near regular hiding places willprovide much better control thanthose placed where cockroachesmove only occasionally.
Present methods of insecticidalcontrol generally provide temporarycontrol within treated structures.Since some cockroach species invadebuildings from outside, reinfestationcan occur once the insecticide hasdissipated. To solve this problem,outdoor populations also must becontrolled. For example, when wood
roaches become numerous in thehome, use of chemicals inside willprovide short-term control. Locating,treating or removing outside shelterscan provide effective long-termcontrol.
To eliminate an establishedinfestation from a building, firstremove as many routes of reinfesta-tion as you can, then thoroughlyclean the building and apply anapproved chemical concentrating oncracks, crevices and hiding places.The type of chemical selected and theapplication method used will dependon the location and nature of theinfestation. Chemicals have differentcapabilities and pesticide selectionshould be based on the species of theinsect, application technique, surfacesto be treated and information on thelabel.
Each cockroach problem must bestudied and control measures used inaccordance with the location, extentand nature of the infestation. With arange of chemicals, formulations andapplication techniques available, it isimportant to select the appropriatecombination to provide the desiredcontrol.
Cockroaches
23
CockroachesQuestions
1. (19) The ___ cockroach carries theegg capsule protruding from herbody until the eggs are ready tohatch.a. Americanb. Germanc. Brownbandedd. Oriental
2. (19) In the United States there areabout ___ species of cockroaches.a. 28b. 40c. 55d. 63
3. (20) The largest adult of thecommon cockroach species is the:a. Germanb. Americanc. Brownbandedd. Oriental
4. (20) The ___ cockroach hasyellow transverse bands acrossthe base of the wings andabdomen.a. Germanb. Americanc. Brownbandedd. Oriental
5. (21) The ___ cockroach appears tohave lower water requirementsthan the other cockroaches.a. Germanb. Americanc. Brownbandedd. Oriental
6. (21) Chemicals must be appliedover a greater area of the build-ing to control the ___ cockroach.a. Germanb. Americanc. Brownbandedd. Subslab dwelling
7. (22) Present methods of insecti-cidal control of cockroachesprovide:a. Temporary controlb. Annual controlc. Permanent controld. No controle. All the above
24
Pests may enter storage or foodprocessing facilities in two ways:(1) penetration through ineffectivepest-proofing of walls, doors, win-dows and roofs, and (2) entry withcommodities, ingredients or otherraw materials and/or supplies.
Areas of ConcernFood plants have five areas
of activity where pests must becontrolled:
■ Grounds, the building exteriorand the area around the plant.
■ Receiving and storage area forincoming materials.
■ Processing area.■ Packaging area.■ Finished product warehouse
and shipping area.Both chemical and non-chemical
controls are important in these areas.Non-chemical controls includeboth preventive maintenance andmechanical and physical measures.
Grounds and Building Exterior
Non-chemical Controls■ Eliminate all exposed dirt
surfaces by paving all roadwaysor parking areas and maintain-ing well-kept lawns. This willreduce contamination from dirt,microbes and other airborneparticles.
■ Provide good drainage to helpkeep the area clean and dry.
■ Place outside lighting awayfrom buildings and focus thelights toward buildings. Thishelps keep night-flying insectsaway from doors and windows.
■ Screen potential bird roostingareas.
■ Store equipment so it does notbecome a place for pests to hide.
■ Remove all litter, weeds andgrass clippings.
■ Eliminate any waste that mayaccumulate near exhaustsystems.
■ Rodent-proof and bird-proofloading docks, doors, walls,windows and roofs.
■ Use rodent, insect and birdtraps as necessary.
Chemical Controls■ Bait stations for rodents.■ Baits, fogs and sprays for
insects.■ Chemical repellents or avicides
for birds.
Receiving and Storage Areas
Non-chemical Controls■ Visually inspect all vehicles,
ingredients and materials toensure that pests are notbrought into storage areas.
■ Store ingredients and materialsfar enough away from walls topermit access for inspection.
■ Use FIFO (first in-first out)rotation of incoming materials.
■ Use traps or other methods forrodents.
■ Use air curtains at dock andpedestrian doors to keep insectsout.
■ Use monitoring methods todetect insects.
Chemical Controls
For insects:■ Space treatment with
nonresiduals.■ Crack and crevice treatment
with residuals.■ Spot treatments with residuals.■ Periodic general treatment.■ Treatment of raw bulk com-
modities with protectants onreceipt and fumigants duringstorage where applicable.
For rodents:■ Bait stations, in non-food areas.
Processing and Packaging Areas
Non-chemical Controls■ Place rodent traps near doors
if situation warrants.■ Screen all windows that can
be opened.■ Eliminate cracks, crevices and
other places where pests mayhide.
■ Where possible, locate equip-ment off the floor and awayfrom walls for inspection andcleaning.
Food-Plant Pest
Treatment Areas
25
Food-Plant Pest
Treatment Areas■ Keep these areas clean and free
of litter.■ Clean interiors and exteriors of
equipment regularly.
Chemical Controls
For insects:■ Space treatment with
nonresiduals.■ Spot treatment and
nonresiduals.■ Crack and crevice treatment
with residuals.■ Contact treatment with
nonresiduals.■ Periodic general treatments.
Finished Product and ShippingAreas
Use the same pest control methodsin the finished products warehouseas in the materials receipt and storagearea.
Vehicle inspection is essential toprevent the finished products frombeing placed in a pest-contaminatedcarrier. Vehicle inspection is difficult,particularly for boxcars and truckswith false walls or end-liners. Ifvehicles are dirty or infested, donot use them.
Chemical Controls in Vehicles
Before loading, consider:■ Space treatment.■ Crack and crevice treatment.
After loading, use:■ General treatment—usually a
solid fumigant—for in-transitcontrol.
Forms of Pesticide ChemicalsAerosols
Advantages■ Excellent for flying or exposed
insect pests.■ Disperse well if used correctly.■ Convenient and easy to store.■ Usually leave little surface
deposit.■ Store well during normal use
period.■ Available for hand operations
or can be installed as a timedrelease system.
Limitations■ No lasting protection.■ Good only for exposed pests.■ Hazardous if container is
punctured or overheated.■ Usually cannot be used during
food processing or when peopleare present.
■ Hazardous around open flamesand sparks.
Liquids—Sprays
Advantages■ Usually provide a deposit on
surface.■ Can easily be directed onto
surface for treatment.■ Easy to store, transport and
handle.■ Adaptable for use in many
kinds of equipment.
Limitations■ May be hazardous to use
around electrical outlets (wateror oil sprays).
■ May damage or stain wallpaper,varnish and many fabrics(water or oil sprays).
■ Require agitation duringapplication (wettable powders).
■ May be hazardous around openflame (oil sprays).
■ May damage or etch asphalt,plastic tile or rubber products(oil sprays).
■ May make floors slippery (oilsprays).
■ May damage living plants (oilsprays).
VaporsVapors are released by supple-
mentary heat or by inherent highvapor pressure to produce a gas.They usually are dispersed fromimpregnated resin strips orvaporizers.
Advantages■ Easy to apply and safe to
handle.■ Can be used where fumigant
tolerances may be exceeded.■ Sealed building not as essential
as for fumigants.■ Effective against flying insects
such as moths and flies.
26
Food-Plant Pest
Treatment AreasLimitations
■ Will not penetrate commoditiesin concentrations lethal to targetpests.
■ Not effective against beetles.■ Resin strips cannot be used
in plant areas where food isexposed.
Dusts
Advantages■ Excellent for crack and crevice
treatments.■ May be purchased ready to use.■ Usually require only simple
and lightweight applicationequipment.
■ Safe for use around electricalequipment.
Limitations■ Drift easily.■ Easily dislodged from treated
surface (should not be appliedon equipment or above food-contact surfaces).
■ Generally bulky to store.
Baits
Advantages■ Often can control specific pests.■ Easily distributed.■ Easily monitored and
recovered.■ Used in small amounts.
Limitations■ Can be dangerous to nontarget
animals.■ Often not as attractive as
natural food supply.■ Rodents must feed for 5 to
15 days on an anticoagulantrodenticide before it is lethal.
■ Rodents feeding on poison baitsmay die anywhere and goundetected, causing sanitationproblems.
27
Food-Plant Pest
Treatment AreasQuestions
1. (24) Areas of concern for pestcontrol at food plants include:a. Exterior building and sur-
rounding groundsb. Receiving and storage areas
for incoming materialc. Processing and packaging
areasd. All the above
2. (24) Non-chemical controls forexterior buildings and surround-ing grounds may include:a. Providing good drainage of
rain waterb. Screening of potential bird
roostsc. Eliminate waste from exhaust
systemsd. All the above
3. (24) Chemical control techniquesfor receiving and storage areas offood plants may include:a. Space treatmentsb. Crack and crevice treatmentsc. General treatmentsd. All the above
4. (25) The same pest controlmethods can be used in thefinished product and shipping asin the:a. Exterior building and sur-
rounding groundsb. Receiving and storage area for
incoming materialsc. Processing areasd. Packaging areas
5. (25) An advantage of aerosols isthat:a. They provide a long lasting
surface depositb. They can be used in place of
fumigantsc. They are excellent for flying
insectsd. They require agitation during
mixing
6. (25) An advantage of liquidsprays in food plants is that they:a. May be hazardous around
electrical equipmentb. Usually provide a surface
depositc. Can be used in place of
fumigantsd. Are good only for exposed
pests
7. (26) A limitation of dusts in foodplants is that they:a. Drift easilyb. Are excellent for flying insectsc. May damage asphalt and
plastic tiled. Can be used in place of
vapors
8. (26) A disadvantage of baits infood plants is that they:a. Often control specific pestsb. Are used in small amountsc. Are easily distributedd. Can be dangerous to non-
target animals
28
Pre-Harvest PreparationThe following steps are necessary
for proper storage in grain bins andelevators:
■ Bins and adjacent structuresshould be thoroughly cleanedof old grain, grain residues,dust and any other material thatmay harbor stored grain insectsand be a source of infestation ofnew grain.
■ Clean up spilled grain outsideof building such as alongrailroad tracks and aroundloading or unloading areas.
■ Properly dispose of abovematerials so they will not infestany stored grain or productsnear the disposal site.
■ Repair, replace, plug or other-wise correct conditions thatallow entrance of rodents, birdsor other pests into the buildings.
■ Clean grounds of weeds, debrisand other materials that mayprovide shelter for insects,rodents or birds. Store equip-ment properly.
■ Train personnel in recognitionof pests, safe use of pesticides,overall safety and emergencyprocedures.
■ Install temperature monitors.■ Apply residual insecticidal
spray to interior walls andceilings of adjacent structures(that have been thoroughlycleaned). See that the insecticidegets into cracks, crevices andout-of-the-way niches. Seesection on Residual Sprays.
■ It may be necessary to fumigatethe empty structure to eliminatehidden infestations such asthose below perforated floorswhere cleaning is impractical.
■ Fumigate any grain that willremain in storage, if it hasinsects, when new grain is beingaccepted.
Harvest OperationsDuring harvest, do the following:■ Keep harvesting and conveying
equipment properly adjusted tominimize breakage which canopen up otherwise sound grainto invasion by a broader rangeof stored grain pests.
■ Do not store the first fewbushels of grain passingthrough harvesting equipment.This grain scours out hiddeninfestations attacking residualgrain left over from the lastharvest.
■ Visually check incoming grainfor presence of stored graininsects. Be alert for previouslystored grain that may come inas though it were “new grain.”
■ If deemed necessary, incorpo-rate a fumigant or grainprotectant into newly receivedgrain as it goes into storage. Seesection on Grain Protectants.
■ Regularly clean-up arounddump pits and conveyingequipment.
■ Separate excess dockage andfines from grain going tostorage. Use distributors tospread allowable dockage andfines throughout grain mass.
■ Separate dockage and finesfrom grain going to a dryer.Do not recombine.
■ Use separate bins for “dry” and“wet” grain. Splitting of wetgrain into “wet” and “very wet”may be necessary to do anorderly job of keeping grain incondition and making effectiveuse of dryers and aerationequipment.
■ Watch for evidence of rodentor bird invasion when harvestapproaches completion.
Post-Harvest OperationsInspect grain thoroughly and
regularly for signs of insect infesta-tion. Inspect every 2 months whengrain temperatures are below55 to 60˚F, and monthly whengrain temperatures are warmer.
Grain Handling
29
First, sample top-center of grain inthe bin. Insert the probe or grain trierhorizontally about or less than4 inches deep. Then take moresurface probes around the bin about1 foot from the walls. Finally, probevertically at various locations in thebin to as great a depth as possible.
Carefully sieve and examine eachsample. Note all insects and thepresence of any damaged grain,flour, or other signs of infestation.Remember, the earlier the infestationis detected, the more damage can beprevented.
■ Monitor all bins of stored grainby appropriate means. Temp-erature increase may indicateinsect activity.
■ Immediately inspect grain ifsnow melts quickly from theroof of unheated storagestructures. Heating may becaused by insect or moldgrowth.
■ Check “hot spots” for insectactivity by using samplingprobes. This may not be practi-cal for deep bins.
■ Use “turning” to break up hotspots due to mold or bacterialactivity. Sample grain at bindischarge for possible insectinfestation.
■ If insect infestation is found orsuspected, use fumigants tocontrol the infestation. Seesection on “Fumigation ofStored Products.”
■ Inspect transport equipmentbefore loading out grain forshipment. Railroad cars oftenneed cleaning to preventcontamination of grain by othermaterials with resulting downgrading and financial loss.
■ Under some circumstances itmay be desirable to fumigategrain in rail cars while in transitor on sidings. See “Fumigationof Stored Products” and checkcurrent guidelines on thelegality of this practice.
■ Have regular checks of pest baitstations and/or traps.
Grain Handling■ Check at regular intervals for
evidence of rodent, bird or pestinvasion. Make regular inspec-tions of buildings and groundsfor possible access points.
Use of Sprays andProtectants
Residual SpraysThe purpose is to kill insects that
are located in cracks, crevices andother locations which will, if notcontrolled, infest newly stored grain.For approved pesticides, be sure torefer to current recommendationsand actual product labels. Timeapplication one to four weeks beforeharvest or filling the bin.
Safety considerations:■ Personnel must have proper
clothing and equipment so as tokeep their exposure to pesti-cides at a minimum.
■ Personnel exposed to thepesticides should thoroughlywash hands, face and exposedskin after application is com-pleted or at the end of the day.
■ A filtered air supply should beused by personnel in enclosedspaces if pesticides are being orhave recently been applied.
■ Be aware of accidental exposureof pets, livestock or people whomay be in the vicinity of thestructure.
■ Solvents may be equally ormore hazardous than thepesticide being used.
Grain ProtectantsProtectants are insecticides that are
designed to remain on the grain as aprotective shield of toxic residuesand are designed to be applieddirectly to the grain. The purpose ofthese products is to prevent infesta-tion of stored grain. They are not aseffective as fumigants in killingstored grain insects which alreadyexist in the grain mass. Fumigantspenetrate into infested grain kernelsbut also diffuse out of grain andstructure in a relatively short timeleaving no protective residue.
30
For approved pesticides, refer tocurrent recommendations and actualproduct labels. Time the applicationfor immediately after harvest as grainfirst enters storage or during transferfrom one bin to another. Protectantsare most appropriate where summer-
Grain Handlingharvested grain is stored into the nextcalendar year and where storage offall-harvested grain is expected to bewell into the next summer (at least).
Safety considerations: Same as forresidual sprays above.
31
Grain HandlingQuestions
1. (28) Which statement applies topre-harvest preparation forstorage in grain bins andelevators?a. If an insect infestation is
found, fumigate.b. Immediately inspect grain if
snow melts quickly fromunheated roof.
c. Bins and adjacent structuresshould be thoroughly cleaned.
d. Use separate bins for “dry”and “wet” grain.
2. (28) Install temperature monitorsin grain bins during the:a. Pre-harvest preparation of the
binsb. Harvest operations of the
grainc. Post-harvest operation after
storaged. Thirteenth week of storage
3. (28) When grain is in the storagebin, it should be inspected every2 months when the grain tem-perature is below:a. 55–60˚Fb. 65–70˚Fc. 75–80˚Fd. 85–90˚F
4. (29) When monitoring grain instorage bins, you should:a. Be aware of grain tempera-
ture increaseb. “Turn” the grain break up
hot-spots caused by moldsand/or bacterial growth
c. Have regular checks of pestbait stations/or traps
d. All the above
5. (29) The purpose of residualsprays for stored grain is to:a. Control insects that are
located in cracks and crevicesin the bin
b. Increase the moisture contentof the grain
c. Control the level of dustassociated with stored grain
d. Protect the structural wood inthe bin from insect attack
6. (29) Grain protectant sprayapplications are:a. Applied only to the bin wall
surfacesb. Applied to the space above
the grainc. Applied directly to the graind. Applied around the outside
base of the bin to protect itfrom rodents entering
32
While this manual containsconsiderable information, it is not allinclusive. If information in thismanual conflicts with any pesticidelabel, the information on the labelmust be considered correct.
FumigantsFumigants are defined as those
pesticides which by themselves or incombination with any other sub-stances are or become a gas or amixture of gases. Fumigants will killor control a pest and also are toxic tohumans. Various aerosol spacesprays (a suspension of liquid in air)are not considered fumigants.
Fumigants penetrate cracks,crevices and the commodity beingtreated. They must reach the targetpests as gases to be effective. As soonas a fumigant diffuses from the targetarea, reinfestation can occur. Fumi-gants must be applied in enclosedareas; the gas released must reach alethal concentration in all parts of theinfested storage environment and theconcentration must be held for aminimum amount of time to beeffective.
Advantages■ Toxic to many pests.■ Can be applied by various
methods.■ Some may be applied without
disturbing the commodity.■ Penetrate structures, commodi-
ties and equipment.■ Readily available and
economical.■ Quick acting.■ Only practical method for
infested commodities such asstored grain.
Disadvantages■ Toxic to humans.■ Require trained applicators.■ Target area or commodity must
be enclosed.■ May injure seed germination.■ Temperature requirements may
be hard to meet, especially innorthern climates.
Fumigation of
Stored Products■ Control is temporary—no
residual action.■ May damage some commodities
and/or equipment.
Selection of FumigantsWhen choosing a fumigant,
consider:■ Toxicity to the target pest.■ Volatility and ability to
penetrate.■ Corrosive, flammability and
explosive potential.■ Warning properties and detec-
tion methods.■ Effect on seed germination and
finished product quality.■ Residue tolerances.■ Availability.■ Ease of application.■ Cost.
Fumigation VariablesSeveral factors can change the
efficiency of fumigants. Considerthese when selecting a formulationand dosage.
TemperatureThe fumigant may not kill the
pests if the product or space beingfumigated is below 10˚C (50˚F) orabove 46˚C (115˚F). The effect oftemperature varies according to thespecific fumigant being used.
MoistureAs the moisture content of a
commodity increases, it becomesmore difficult for a fumigant topenetrate it. This makes fumigantsless effective on insects. For somefumigants, this also increases thepotential for residues exceeding legaltolerances. Adequate moisture isrequired for the generation of somefumigants.
PestsSusceptibility to fumigants
depends on species, habitat and stageof development. During some stagesof their life cycle, they are less sus-ceptible than during others. Activeinsects are more susceptible thansluggish, diapausing forms.
StructureConsider the condition of the
structure, the type of construction
33
and the product it contains. Awooden structure, even when sealedwell, will not retain fumigants as wellas metal, plastic, masonry or con-crete. Fumigation in vacuum cham-bers allows increased efficiency.Vacuum chambers must never beused for phosphine.
Preparation forFumigation
PlanningUnderstand fully the facility and
commodity to be fumigated, includ-ing the:
■ Design of the structure, as wellas adjacent and connectingstructures both above andbelow ground.
■ Persons or animals expected tobe at or near the area to befumigated.
■ The commodity, its history(previous fumigation, tempera-ture, moisture), condition, andintended purpose (seed or foodprocessing).
■ Availability of emergencyshutoff stations for electricity,water and gas.
■ Location of nearest telephoneand numbers for fire or policedepartments, hospitals andphysician.
Select a suitable fumigant. Under-stand label directions, warnings andantidotes. You should notify localmedical, fire and police authoritiesand other security personnel about:
■ Chemicals to be used.■ Proposed date and time of use.■ Type of respiratory protection
required.■ Fire hazard rating.■ Name and phone number of
person to contact in event ofemergency.
Have alternate application andprotective equipment and replace-ment parts available. Display warn-ing signs near points of entry andprovide for security of buildings.Have necessary first aid equipmentavailable. Before treatment is started,develop plans to ventilate the area
when the treatment period is over.Post-treatment gas concentrationlevels must be determined andwritten records maintained todocument that harmful levels havedissipated. Grain cannot be legallyreleased back into commerce untilthis step has been completed.
Premises InspectionOnce you decide to fumigate,
make a serious on-site inspection.You must ask yourself a number ofquestions and make a number ofdecisions. Frequently, the success orfailure of the fumigation operationwill depend upon what you learn,what you decide and how you plan.Some of these questions shouldinclude:
■ If the structure itself is notinfested, could the infestedcommodity be moved fromthe building and fumigatedelsewhere?
■ Assuming that removal of theinfested commodity from thebuilding is not practical, canyou fumigate the commodityin place?
■ Is there enough room betweenthe commodity and walls orpartitions so you can seal thetarp to the floor.
■ What is the volume of thecommodity?
■ What is the volume of thebuilding?
■ Can the structure itself be madereasonably airtight or will it benecessary to tarp the entirebuilding?
■ From what materials is thestructure built? (Fumigants willpass through cinder block withno difficulty.)
■ Are there broken windows thatmust be replaced?
■ Are there cracks in the ceiling,walls or floors that must besealed?
■ Are there floor drains or cableconduits that will requiresealing? (There have been anumber of fumigation failuresbecause floor drains understacked commodities went
Fumigation of
Stored Products
34
unnoticed. In one instance, thefumigant leaked into a tele-phone cable tunnel which led toan occupied building. No lossof life occurred, but a numberof people were made ill.)
■ How are you going to handleair conditioning ducts andventilation fans?
■ Will interior partitions interferewith fumigant circulation?
■ Are the interior partitions gastight so they can be relied uponto keep the fumigant fromentering other parts of thestructure?
■ Are there parts of the buildingnot under your control?
■ Can these other operationsbe shut down during thefumigation?
■ What are the building contents?■ Can any of them be damaged
by the fumigant?■ Can such items be removed
during the fumigation?■ If they cannot be removed, can
they be otherwise protected?■ Where are the electrical outlets?■ Of what voltage are they?■ Will the circuits be live during
fumigation?■ Can the outlets be used to
operate your fumigantcirculating fans?
■ Look outside the building.If you tarp the entire structure,can you make a good, tightground seal?
■ Is there shrubbery next to thebuilding that might be damagedeither by the fumigant or byyour digging to make an air-tight fumigation seal?
■ Can this shrubbery be moved?■ How far is it to the nearest
building?■ Does that building have air
conditioning?■ Does it have air intakes that
could draw the fumigantinside—particularly duringaeration?
■ How are you going to aerateyour structure after fumigation?
Fumigation of
Stored Products■ Are there exhaust fans and
where are the fan switches?■ Are there windows and doors
that can be opened for crossventilation?
■ Does the building containany high-priority items thatmay have to be shipped withina few hours notice?
■ Is the structure to be fumigatedso located that your operationsmay attract bystanders? (If so,you should consider asking forpolice assistance to augmentyour own guards.)
■ Where is the nearest medicalfacility?
■ What is the telephone numberof the nearest poison controlcenter?
■ Once you are convinced thatyou have covered everything,prepare a checklist of thingsto do and of materials needed.
■ Don’t rely upon your memory.
The final three questions:■ Am I qualified to do this job?■ What have I overlooked?■ Is fumigation still the best
method of controlling the pestproblem?
Respiratory ProtectionDevices
Gas MasksThe respiratory protection devices
that furnish the minimum protectionare the full-face gas masks. These areequipped with canisters. The canistermust be suitable for protectionagainst the fumigant being used.The canisters contain chemicals thatabsorb the fumigant, and also maycontain a filter.
The life of the canister is limitedand varies with the fumigant usedand the fumigant concentration,temperature and respiration rate.The maximum permissible limitsusually are stated on each canister.Do not exceed these maximum limits.The canister color codes for thevarious fumigants are:
35
Fumigation of
Stored ProductsFumigant Color Code
Chloropicrin BlackMethyl Bromide BlackAluminum Yellow with
Phosphide gray andorange stripe
There are several reasons for usingdevices other than full-face gasmasks with chemical canisters forrespiratory protection. The canistershave limited life. Special canistersmust be available for each fumigant.The canisters provide no protectionat abnormally high (over 2.0 percent)fumigant concentrations. Refer tolabeling and Occupational SafetyHazarad Association (OSHA) regula-tions for additional guidance. Theyprovide no protection in spaces whenoxygen is deficient.
General Suggestions on CanisterUse
1. Discard any canister that hasbeen used for more than itssuggested effective use time at2 percent gas concentration.
2. Discard any canister wheneveran odor of fumigant is detectedas coming through (the absorp-tion material is not working).
3. Discard canisters kept beyondthe expiration dates or more thantwo years after manufacture(even if unused) unless instruc-tion sheet specifically saysotherwise.
4. Do not use a canister-type gasmask to enter a freshly fumigatedarea. The concentration offumigant will overpower evennew absorbent material.
Air-line MasksThese devices have face pieces
similar to the canister gas masks butrather than a canister, the masks areattached to hoses which lead to an airpump. The air then passes througha filter. One air pump can supply airfor several air lines. This devicepermits the fumigators to operatewithin a space being fumigated forindefinite time (Note: There is noprotection against skin absorptionof some fumigants.)
The disadvantages of air-linemasks are that the fumigators musttow the air-line with them. The air-line can become caught or kinkedwhich will shut off the air supply.The engine may fail. The air pumpmust be located so that contaminatedair is not pumped to the fumigator.Air-line masks used in “immediatelydangerous to life and health” (IDLH)atmospheres must have an escapecylinder attached.
Self-Contained BreathingApparatus
There are two types of thesedevices. One is the air pack andthe other is the oxygen breathingapparatus (OBA).
Air PackWith this device, the full-face
mask is attached to a tank of aircarried on the back of the fumigator.This device gives the fumigator themobility of the canister mask anddoes not tie him/her to an air pump.Again, this does not protect againstskin absorption of the fumigant.
With the popularity of SCUBAdiving, it is not difficult to get the airtanks refilled. Depending upon thesize of the tank, the air supply willlast up to an hour. There usually is awarning bell that warns the fumiga-tor when the air supply is runninglow. The disadvantage of the air packis that the fumigator has to carry aheavy tank to complete the work.
OBAThe oxygen breathing apparatus is
similar to the air pack but instead ofa tank to carry, a special canistergenerates the oxygen supply. Thecanister is lightweight and usuallyis worn on the chest. To operate, thefumigator places the canister into itsplace, tightens the connector andblows into the air supply tube onceor twice. The moisture from thebreath activates the chemicals in thecanister which then provide a supplyof oxygen. The supply is good forabout one hour.
There usually is a warning bellthat can be set to warn the fumigatorthat the life of the canister is about to
36
expire. Care must be taken anddirections closely followed for thedisposal of the oxygen-generatingcanisters.
Note: All respiratory protectiondevices must be fit-tested to assureproper protection of the personusing the device.
Physical ExaminationsAll new employees should have
a thorough physical examinationbefore performing any fumigationduties. The examination shouldinclude a liver function test and arespiratory capability test (orequivalents).
All persons working with fumigantsshould have a complete physicalexamination every six to 12 months,depending on the amount of exposure.Again, the examination should includeliver function capability and respira-tory capacity.
Fumigant ApplicationAlways assign at least two persons
to each fumigation. Everyoneinvolved in the fumigation shouldknow first aid and other emergencyprocedures, including personaldecontamination.
Prior to applying the fumigantmake sure that no one is within thestructure to be fumigated. This isparticularly critical if the structureto be fumigated consists of severaladjoining rooms or spaces and/oris a multi-level structure.
Provide watchmen when appro-priate. Secure entrances by guardsor locks. Current law requiresplacarding of structures undergoingfumigation.
Wording must meet postingrequirements (including name, phonenumber of fumigator, etc.) andwarnings must appear in English andSpanish.
Follow label directions exactlywhen applying a fumigant. Considerprevailing winds and other pertinentweather factors such as temperatureand humidity.
Return to the storage area allunused chemicals in clearly labeled,original containers. Dispose of emptycontainers correctly.
Report to company-retainedphysician or to designated personnelany indications of illness or physicaldiscomfort, no matter how minorthey seem. These symptoms andsigns may include dizziness, nausea,headaches and lack of coordination.
Do not consume alcohol for24 hours before or after a fumigation.
Post FumigationBefore re-entry, use a suitable gas
detector as indicated on the label todetermine fumigant concentration.Do not depend on odors. Somefumigant gases are odorless. Wearcorrect respiratory equipment.
Passive gas detection badges,which resemble X-ray exposurebadges, change color or shading toinform wearers that their exposure tothe fumigant may be reaching health-threatening levels.
Turn on all ventilating oraerating fans.
Check for gas concentrations inareas that are expected to aerateslowly.
Remove warning signs when thegas concentration is within safe limitsfor human exposure.
Remove and dispose ofpackaging and waste productsof solid fumigants.
On those occasions when a fumi-gated area must be entered, portablebottled air systems with full-facemask are the safest choice. Absorp-tive filter masks can be used if stepsare taken to make absolutely certainthat the filter cartridges are replacedbefore they lose their effectivenessand if the fumigant concentration isnot high. The “buddy” system shouldalways be practiced; in grain binfumigation, one person outside thebin but within eyesight and hearingrange prepared to give aid if it isnecessary.
Fumigation of
Stored Products
37
Commodities/Pests toConsider for Fumigation
Most fumigation operations aredirected toward the control of insectpests of stored grain, flour, meal, eggnoodles, rice, spaghetti, spices, nutsand similar foods. Control of pests ina few packages of an item can beaccomplished by either heat or cold.When large quantities are involved,fumigation is the answer.
If the infestation is light, thecommodity may be used afterfumigation. Even if the infestation isso heavy that the commodity willhave to be destroyed after fumiga-tion, fumigation may be warrantedto prevent spread of the insects touninfested items.
Stored GrainGranary weevilRed flour beetleLesser grain borer*Indian meal moth (larvae*)Saw-toothed grain beetleAngoumois grain mothFlat grain beetleRice weevilCadelle or flour worm*
Flour and Flour ProductsThese include fry and cake mixes,spaghetti, macaroni, noodles, etc.Flour beetles (Tribolium sp.)
Rice weevilCigarette beetle*Granary weevilDrugstore beetle*Indian meal moth (larvae*)Cadelle*Mediterranean flour mothSaw-toothed grain beetle
SpicesCigarette beetle*Drugstore beetle*Dermestids*
Nuts and Dried FruitIndian meal moth (larvae*)Saw-toothed grain beetleCadelle*Flour beetles (Tribolium sp.)
Dried Peas and BeansCommon bean weevil*Cowpea weevil*
TobaccoCigarette beetle*Drugstore beetle*Dermestids*
Dehydrated Foods(soups, powdered milk)Indian meal moth (larvae*)Dermestids*
*Pests which can penetrate paper orplastic packaging.
Fumigation of
Stored Products
38
Fumigation of
Stored Products Questions
1. (32) To be effective, fumigantsmust:a. Be applied in enclosed areasb. Reach a lethal concentration
in all areasc. Be held at a lethal concentra-
tion for a minimum amountof time
d. All the above
2. (32) Several factors can changethe efficiency of fumigants:a. Corrosive, flammability and
explosive potentialb. The temperature and mois-
ture of the grain massc. The fumigant availability and
costd. The ease of application and
residue tolerance
3. (33) Knowing and understandingthe commodity, its history,condition and future use areimportant when planning to ___for pest control.a. ship it to Chinab. fumigate itc. store itd. sell it quickly
4. (33) Before a fumigated com-modity can be legally releasedback into commerce,a. it must pass a USDA
inspection.b. it must pass an EPA
inspection.c. it must pass a Kansas
Department of Agricultureinspection.
d. written records documentingharmful levels of the fumiganthave dissipated must bemaintained.
5. (34) One of the final questionsyou should ask before doing afumigation is:a. What is the volume of the
commodity?b. What is the voltage of electri-
cal outlets in the men’s room?c. What have I over looked?d. Does the building have air
conditioning?
6. (34) The respiratory device thatfurnishes the minimum protec-tion is the:a. Full-face gas masksb. Air-line masksc. Air packsd. Oxygen breathing apparatus
7. (35) Use of ___ in “immediatelydangerous to life and health”(IDLH) atmospheres must havean escape cylinder attached.a. air packb. air-line masksc. full-face gas masksd. OBA‘s
8. (35) The air pack is an example ofa type of:a. Air-line maskb. Full-face gas maskc. Self-contained breathing
apparatusd. OBA
9. (36) Medical physical examina-tions of persons working withfumigants should include:a. A hearing and taste testb. A liver function and respira-
tory capability testc. A smell and flexibility testd. A sight and touch test
10. (36) Before re-entering a fumi-gated area, you should ___ todetermine the fumigantconcentration.a. release a canary in to the
structureb. send an EPA inspector in to
the structurec. use a suitable gas detector as
indicated on the labeld. send a lawyer in to the
structure
11. (37) Fumigation of a heavyinfestation may be warrantedeven though the commodity willstill be destroyed because:a. Fumigation leaves no residue.b. Fumigation will prevent the
pest from spreading touninfested items.
c. Fumigation is less expensivethan spraying.
d. Fumigation can be carried outover night in most cases.
39
PVC MetalFumigant Probe
Figure 13
Note: After June 30, 1986, thetraditional liquid grain fumigants(carbon tetrachloride, carbon disul-fide, ethylene dibromide, ethylenedichloride, etc.) were no longer legalfor use.
GeneralThere are several important factors
common to all fumigant applicationprocedures.
■ All fumigants are restricted usepesticides and as such, applica-tors must be certified or underthe direct supervision of acertified applicator to obtain oruse them.
■ A plan should be devised forapplication, aeration, moni-toring and disposal of thefumigant so as to minimizeapplicator exposure to the gas.
■ Provision should be made foruniform distribution of the gasthroughout the storage spacebeing fumigated.
■ The condition of the storagefacility and the materials fromwhich it is constructed maydetermine the feasibility ofobtaining a safe, effectivefumigation, i.e. whether theenclosure can be properlysealed to retain a toxic concen-tration of gas long enough tokill target insects.
■ Follow all dosage, exposure,precautionary and safetystatements on the label andtechnical labeling. Placardfumigated structures, monitorgas concentrations and userequired respiratory protection.
■ When applying fumigants fromwithin the space being fumi-gated, two trained individualsare required.
The following suggestions areintended to provide general guide-lines for typical fumigations. Theyare not intended to cover every typeof situation nor are they meant to be
restrictive. Other procedures may beused if they are safe, effective andconsistent with the fumigant and itslabeling.
Fumigation of Farm Bins■ Leakage is the most important
cause of failure in the fumiga-tion of farm storages. Sincestorages often are small, theleakage is high in proportion tothe capacity. Most woodenstructures are too porous andshould be completely coveredby a gas-tight sheet for success-ful fumigation.
■ Seal the bin as tightly as pos-sible, especially doors, eaves,hatches, vents, and aeration/auger ports.
■ Surface of the grain should beleveled and below the storageside walls. Fines should beuniformly distributed through-out the grain mass.
■ Since solid forms (tablets orpellets) of phosphine are mostlikely to be used, provisionmust be made to distribute thegas uniformly throughout thegrain mass. This may be accom-plished (follow label directions)by:— probing tablets or pellets into
the grain at regular intervalsover the surface and to depthsof 5 to 7 feet (Figure 13).
— covering the surface of thegrain with polyethylenesheeting after applying thefumigant from the surface willgreatly reduce the leak rate.
— additionally, applying nomore than 25 percent of thetotal dosage at the bottom ifthe bin is equipped with anaeration system. Caution:Make sure the aeration ductor plenum is dry beforeadding fumigant tablets orpellets to this space. Additionof metallic phosphides towater may result in a fire.Seal the aeration openingwith 4 mil polyethylene.
Fumigation
Methods for
Stored Grain
40
Fumigation
Methods for
Stored Grain
■ Larger bins that are properlysealed (bolted or weldedconstruction) may be fumigatedby applying the solid phosphinetablets or pellets over the sur-face of the grain and recirculat-ing the fumigant through thegrain by means of a small fanand duct system (closed loopfumigation) as in Figure 14. Gasgenerated at the surface of thegrain is taken from the over-space and introduced into thegrain at the bottom of the binand distributed upwardthrough the grain. For details
of this method see “StoredProduct Management” availablefrom the Cooperative ExtensionService, Oklahoma StateUniversity.
■ If the grain can be moved fromone bin to another, uniformdistribution of the gas can beobtained by adding the solidtablets or pellets to the grain asit is placed in storage.
Fumigation of Flat StoragesFumigation of flat storages with
solid tablets or pellets to generatephosphine may require considerableeffort. Sufficient numbers of indi-viduals should be available tocomplete the application rapidlyenough to prevent excessive applica-tor exposure and minimum loss ofgas from the storage.
■ Conduct fumigations duringcooler periods and employother physical means and workpractices to prevent applicatorexposure.
■ Seal any doors, vents, aerationducts, cracks or other sourcesof leaks.
■ Establish a plan for applicationof phosphine tablets or pelletsto the grain to provide uniformdistribution of the gas in thegrain mass.— Apply phosphine tablets or
pellets to the grain by prob-ing at intervals along thelength and width of the flatstorage.
— Tablets or pellets may bedeposited within the grainmass by intermittently drop-ping them into the probe as itis withdrawn from the grain.
— Tarp the surface of the grainas it is treated to preventexcessive loss of gas from thegrain.
■ It is unlikely that flat storagestructures would be sufficientlywell sealed to allow closed loopfumigation with phosphine orrecirculation with methylbromide (See fumigation ofvertical storages).
SealAerationFan
SealAeration
Fan
Top View
Side View
1/4–1 HPClosed LoopFumigationBlower(2 Places)
6” Suction Pipes
SealAeration
Fan
Shut OffValve(2 Places)
Two CLF blowers with separate pipe manifolds on large welded steel or concrete tanks.
Figure 14
Seal BaseOpening
Seal BaseOpening
Seal BaseOpening
3” or 4” dia. 3” or 4” dia.
4” dia.
3” or 4” dia.
1/12 HP Blower(Explosion
Proof)
4” dia.
1/12 HPTEFCBlower
SealAerationFan
CLF systems for individual concrete silos.
Manifold Pipesto 3 Aeration
Fans per Blower
4” Pressure Pipes
1/12–1/5 HPClosed LoopFumigationBlower(2 Places)
41
Fumigation
Methods for
Structures and
Other Enclosures
Fumigation of VerticalStorages
Concrete upright bins and othersilos in which grain can be rapidlytransferred provide the opportunityto use automated systems of fumi-gant application.
■ Close and seal all openings tomake the structure as airtightas possible. Prior to fumigation,seal the bin discharge and thevents near the bin top whichconnect to adjacent bins.
■ Pellets or tablets may be appliedcontinuously by an automaticdispenser or by hand as thegrain is turned or loaded intothe bin.— Application can be at various
locations in the grain stream,i.e. conveying belt or con-veyor to the bin, at entry tothe bin, or in the up leg of theelevator by automaticdispenser.
— Seal and placard the tophatch of the bin when thefumigant application iscomplete.
■ Phosphine also may be appliedusing the “closed loop fumiga-tion” method.— Pellets or tablets are placed
on the surface of the grain inthe bin using the headspaceto generate the gas.
— The gas is then moved by ductand fan to the bottom of thebin and up through the grain.
■ Methyl bromide gas is bestapplied by the recirculationmethod in elevator silos.— Methyl bromide, compressed
as a liquid in cylinders, isreleased as a vapor into a fanand duct system whichincludes the silo as part ofthe system.
— The gas is recirculatedthrough the grain for theprescribed exposure periodto allow uniform distributionof the gas throughout thegrain mass. The gas is thenexhausted from the grain to
prevent damage or excessivebromide levels in the grain.
■ When fumigating silos in grainelevators, adjacent areas must becarefully monitored for the pres-ence of hazardous levels of gas.— Gas levels in work areas
must not exceed 0.3 ppm forphosphine or 5 ppm formethyl bromide.
— Pockets of methyl bromidemay accumulate in low areas(boot pits, etc.) because it isheavier than air.
Fumigation of Structures,Facilities and OtherEnclosures
Fumigation of FoodProcessing Plants andWarehouses
Safe, effective fumigation of entirestructures requires extensive plan-ning and preparation. This type oftreatment is primarily aimed atdisinfesting the structure and itsequipment rather than destroying aninfestation in a commodity, such asgrain.
■ Check with appropriateauthorities to become familiarwith local regulations regardingfumigations.
■ Notify fire, police, medical andother local authorities (asrequired) of the fumigation.
■ Select a fumigant that will alloweffective treatment of the facilitywithin the available time.— Using the labeling, calculate
the dosage and exposureperiod based on the volumeand tightness of the structure.
— Note any physical and/orchemical hazards related tothe fumigant.
■ Prepare the facility for fumiga-tion by sealing the structure toprevent gas leakage.— Close and seal all external
openings, including win-dows, doors, exhaust ventila-tors, air intakes, drain pipes,tunnels, etc.
42
— Processing equipment withinthe structure, i.e. bucketelevators, conveyors, hop-pers, bins, spouts and otherpieces of equipment shouldbe opened to allow fumigantpenetration.
■ Establish a plan to minimizeexposure of applicators duringrelease of the fumigant andduring aeration of the structure.Have personal protectiveequipment available and beaware of the maximum expo-sure levels for the fumigantbeing used.
■ Immediately prior to introduc-ing the fumigant, check that allentrances are locked andplacarded and that all personnelhave left the facility. In someinstances, it may be necessary topost watchmen or guards topreclude persons from enteringthe fumigated facility.
■ Apply the fumigant accordingto the label and technicallabeling.
■ Following the fumigation,aerate the facility.— Using gas detection equip-
ment, monitor the gas levelsto assure proper aeration andthat the facility is safe forworkers to enter.
— Specific attention should begiven to ventilating enclosedand low areas in the facilityto assure that heavier than airgases have been removed.
■ Remove any fumigant residuesand/or containers and thefumigation warning placards.
Fumigation of TransportVehicles
Railcars, containers, trucks, vans,and other transport vehicles, eitherempty or loaded with commodities,may, at times, require fumigation.Very specific conditions apply to thistype of fumigation and it is sug-gested that the labeling be referred tofor guidance. Some general guide-lines are as follows:
Fumigation
Methods for
Structures and
Other Enclosures
■ Bulk commodities to whichphosphine producing tablets orpellets may be added directlyare fumigated essentially thesame as flat storages with thetransport vehicle acting as the“storage structure.”— Railcars and containers
shipped piggyback by railmay be fumigated in transit.
— It is illegal to move fumi-gated trucks, trailers, vans,etc., over public roads untilthey have been aerated.
■ Processed food commoditiesalso may be fumigated intransport vehicles, with theexception that residues oftablets, pellets or other phos-phine forms are not allowed inor on the processed products ortheir packaging.— Various forms of packaging
for aluminum and magne-sium phosphide are availableto preclude or contain thedust residues that remainwhen phosphine gas isgenerated.
— Only railcars and containersshipped piggyback may befumigated in transit.
■ Consignees of railcars andcontainers fumigated in transitmust be aware and trained forproper monitoring of gasconcentrations in the vehicleand processed commodity attime of receipt.
■ Empty transport vehiclesoccasionally may be fumigatedto assure they are not infestedbefore use to transport pro-cessed food products.
■ All transport vehicles must beproperly placarded duringfumigation.
■ Shipboard, intransit ship orshiphold fumigations aregoverned by U.S. Coast GuardRegulations. Both phosphineand methyl bromide are labeledfor use.
43
Fumigation
Methods for
Structures and
Other Enclosures
Vault FumigationAtmospheric and vacuum vaults
are chambers primarily designed forfumigation of small lots of commodi-ties or materials. They can be smallstructures located well apart fromother facilities or special chamberswithin a structure. Some are speciallybuilt for fumigation, others aremodified from other structures.
■ Atmospheric vaults are simplegas-tight chambers that providea constant volume space forfumigation with either methylbromide or phosphine.— Application of fumigant and
aeration can be accomplishedwith minimum exposure forthe applicator.
— Chambers should beplacarded when in use.
■ Vacuum fumigation vaults arespecifically designed for fumi-gation under reduced pressures.— Vacuum vaults allow fumi-
gation of sensitive commodi-ties and other items withreduced dosages and expo-sure times.
— Application of the fumigantand aeration usually areautomated. After fumigation,release of the vacuum shouldbe followed by two changesof air in the chamber.
— Limited uses of methylbromide are labeled forvacuum fumigation.
Tarpaulin FumigationTarpaulin fumigation involves the
placement of a gas-tight materialover the commodity or structure to
be fumigated. Tarps may be speciallymade for fumigation, such as impreg-nated nylon, or they may be sheetpolyethylene.
■ Use of plastic sheeting to covercommodities is one of theeasiest and least expensivemeans for providing relativelygas-tight enclosures forfumigation.— The volume of these enclo-
sures can vary widely froma few cubic feet to coveringan entire storage structure.
— Plastic sheets may be sealedtogether to provide sufficientwidth of material to coverlarge stacks of commodityand provide for adequatesealing to the floor or othersurface.
— If the base on which thecommodity rests is of woodor other porous material, thecommodity should berepositioned onto polyethyl-ene prior to being covered forfumigation.
— The plastic covering of thecommodity must be sealed tothe floor. Use sand or watersnakes (plastic or fabric tubesfilled with sand or plastictubes filled with water) orother means for sealing.
■ Method of fumigant applicationwill vary depending on thecommodity and/or fumigant.Follow label directions.
■ Place warning placards atconspicuous points on theenclosure.
44
Fumigation Methods
for Stored Grain,
Structures and
Other Enclosures
Questions
1. (39) In the fumigation of farmstorage bins, ___ is the mostcommon cause of failure.a. insufficient dosage of fumi-
gant is appliedb. temperature of grain is too
lowc. the moisture of the grain is
too highd. leakage of gas from the bin
2. (39) Provisions to distribute gasesuniformly throughout the grainmass include:a. Probing tablets/pellets in to
grain at regular intervalsb. Covering the grain surface
with a polyethylene sheetingafter fumigant application
c. Apply no more than 25% ofthe dosage at the bottomof the bin with aerationequipment
d. All the above
3. (40) When fumigating flatstorages, you should:a. Conduct fumigations during
cool weatherb. Seal all sources of possible
leaksc. Have a plan to provide
uniform gas distributiond. All the above
4. (41) Vertical grain storage binsand silos with rapid graintransfer systems:a. provide an opportunity
for automated fumigantapplication
b. can not be legally fumigatedc. can only utilize liquid
fumigantsd. can only be fumigated during
July
5. (41) Fumigant gas levels in workareas must not exceed ___ ppmfor phosphine.a. 0.3b. 0.7c. 1.0d. 5.0
6. (41) Whole structure fumigationis primarily aimed at:a. controlling pests in packaged
goodsb. disinfesting the structure
rather than the contentsc. controlling pests of stored
wheatd. controlling pests of stored
corn
7. (42) It is legal to fumigate only___ while in transit:a. trucksb. trailersc. railcarsd. vans
8. (43) Atmospheric vault fumiga-tion means that:a. The fumigation is in a vault
up high in the atmosphereb. The atmosphere is pressur-
ized in the vault to controlthe pests
c. The atmosphere (air) ispumped out of the vault,thereby suffocating the pests
d. The fumigant is released in tothe vault at normal atmo-spheric pressure
9. (43) Vacuum vault fumigationmeans that:a. The vault is placed in a
vacuum before the gas isreleased
b. The vault is designed forfumigation under reducedatmospheric pressure
c. The commodity is put in avacuum before going in to thevault
d. The atmosphere (air) ispumped out of the vault,thereby suffocating the pests
10. (43) The fumigation techniqueof covering the commodity orstructure to be fumigated witha gas-tight material is called:a. Atmospheric fumigationb. Vacuum fumigationc. Tarpaulin fumigationd. Transport fumigation
45
Aluminum and MagnesiumPhosphides
Properties: Various forms ofaluminum or magnesium phosphidesreact with moisture to evolve phos-phine gas (PH3). Hydrogen phos-phide gas is highly toxic to insects,burrowing pests, humans and otherforms of animal life. In addition toit’s toxic properties, the gas willcorrode certain metals and mayignite spontaneously in air at concen-trations above it’s lower flammablelimit of 1.8% (v/v).
Phosphine easily penetrates intoproducts, but being only slightlyheavier than air (sp. gr: 1.214) caneasily be moved by convection orother air currents. To maintain toxicconcentration of the gas requirestight sealing of the space beingfumigated.
Tablets and pellets are formed byadding paraffin and commonly includeammonium carbonate which liberatesammonia and carbon dioxide. Thesegases are essentially non-flammableand act as inert agents to reduce firehazards. Ammonia gas also serves asa warning agent.
Human Hazards: Tablets, pelletsor dust that are swallowed, or ifgas is inhaled, are highly toxic tohumans. The maximum safe expo-sure limit (for 40 hours/week) is0.3 ppm (0.00003 percent) in air.Garlic odor warns of toxic concentra-tions but may not always be presentabove 0.3 ppm. Gas detectors shouldbe used to ensure safe workinglevels. Symptoms include fatigue,ringing in ears, nausea, pressure inchest, intestinal pain, diarrhea andvomiting. PH3 apparently is notchronic and is not absorbed throughthe skin in appreciable amounts.
Physical/Chemical Hazards:Aluminum and magnesium phos-phide tablets, pellets and dust willrapidly release PH3 when exposed tomoisture in the air, or to water orother liquids. High concentrationsof gas may cause an increase in
temperature and may ignite sponta-neously. Metals such as copper, brassand other copper alloys, and preciousmetals such as gold and silver aresubject to corrosion by phosphine.
Uses: READ THE LABEL. Tabletsusually are probed into grain inshallow storage structures. Pelletsusually are introduced in grain byautomatic applicators as grain flowsinto vertical storage bins. Sachets andvarious other forms of packagedaluminum or magnesium phosphideare used in other specialized types offumigation. Refer to product techni-cal labeling for specific applicationsand uses. Tolerances have been setfor residues on raw agriculturalcommodities and on processed cerealproducts.
Methyl Bromide (MB)Properties: At normal tempera-
tures and pressures, methyl bromideis an odorless, colorless gas. It isgenerally transported in cylindersunder pressure as a liquid. The gas isover three times heavier than air(sp. gr: 3.27). MB quickly and deeplypenetrates into grains and cerealproducts under normal atmosphericconditions and following fumigationthe vapors dissipate rapidly.Repeated or excessively high dosagefumigations of seeds or cerealproduct may result in reducedviability of the seeds and cumulativeincrease in inorganic bromide resi-dues in raw agricultural productsand processed cereal products.
Human Hazard: This gas is not astoxic as some other fumigants,however, because it lacks an odor itmust be handled with extremecaution. Liquid MB in contact withthe skin will cause severe blisters.The maximum safe exposure limit is5 ppm. Acute and chronic symptomsmay occur. Acute exposure causespulmonary injury and circulatoryfailure. Chronic exposures result inneurological symptoms (headache,incoordination, visual disturbances)which are often irreversible. Delayedsymptoms and lack of odor make thisfumigant hazardous to use.
Types of
Fumigants
46
The presence of MB gas can bedetected by halide leak detectors butmore reliably it is measured bydetector tubes or thermal conductivity.
Physical/Chemical Hazards:Methyl bromide in air is considerednon-flammable; however, liquidmethyl bromide in contact withaluminum may result in spontaneousignition. Certain commodities(iodized salt, sponge rubber, leathergoods, viscose rayons, photo chemi-cals, etc.) should not be exposed toMB.
Uses: READ THE LABEL. MBreadily penetrates flour and milledproducts and has been used for thispurpose. However, because ofpotential residue problems this usehas diminished. MB fumigation ofgrain requires gas recirculationsystems which are not common inmost farm and elevator facilities.Grain processing facility fumigationhas constituted a major use of thisgas, however, the declaration of MBas an ozone depletor is changing thissituation. Refer to technical labelingfor specific applications and uses.Tolerances have been set for inor-ganic bromides on raw agriculturaland in processed cereal products.
Chloropicrin (CP)Properties: Commonly known as
“tear gas,” this clear liquid evolvesan intense burning vapor. Becauseof this property, chloropicrin hasbeen used as a warning agent insome MB formulations. It is one ofthe most toxic fumigants to insects.Even though “tear gas” is over fiveand a half times as heavy as air(sp. gr.: 5.676), when it was usedas a grain fumigant it was absorbedby the grain and was not effective inpenetration to any depth in the bin.Commodities tended to release theabsorbed gas slowly, making itunpleasant to handle.
Human Hazards: The “tear gas”effect of chloropicrin is helpful inpreventing persons from staying indangerous concentrations of the gas.A concentration of 2.4g/m3
(=240 ppm) can cause death fromacute pulmonary edema in oneminute. A concentration as low as1 ppm in air causes an intensesmarting pain in the eyes and thereaction is to leave the area immedi-ately. Continued exposure may causeserious lung injury. The maximumsafe exposure limit is 0.1 ppm.
Physical/Chemical Hazards:Chloropicrin is a non-flammableliquid that may be corrosive undercertain conditions. Do not use waterto clean equipment or use magne-sium, aluminum, or alkali metalsas containers.
Uses: Chloropicrin is no longerlabeled for direct application tograins; however, it is effective indestroying infestation in full-flooraeration bottoms or empty grain bins.
Threshold Limit ValuesThreshold limit values (TLV’s) for
fumigants are listed in Table 5. Theyrefer to airborne concentrations ofsubstances and represent conditionsunder which it is believed that nearlyall workers may be repeatedlyexposed day after day withoutadverse effects. These TLV’s arebased on time weighted averageconcentrations for a normal 8-hourwork day or 40-hour work week.
Types of
Fumigants
TABLE 5.Exposure to Fumigants
Threshold limit values (TLV’s) for workers Fumigant odors andexposed to fumigants during a normal 8-hour detection
work day or 40-hour work week* levels
Odor detectionSubstance ppma mg/m3b ppm Odor
Phosphine 0.3 0.4 1 Garlic
Methyl bromide 5.0 60 — No odor
Chloropicrin 0.1 0.7 1–3 Strong, Biting
*Source—American Conference of Governmental Industrial Hygienists,Threshold Limit Values for Chemical Substances in Workroom Air Adoptedby ACGIH for 1979; P.O. Box 1937, Cincinnati, Ohio 45201. The TLV’s in thetable should be used as guides in the control of health hazards and should notbe used as fine lines between safe and dangerous concentrations. They aresubject to variation and the latest documentation should be consulted for themost current values. V.K. Rowe, DowElanco Chemical Company, ResearchDepartment.aParts of vapor or gas per million parts of contaminated air by volume at 25°Cand 760 mm H.G. pressure.
bApproximate milligrams of substance per cubic meter of air.
47
Safe Use of FumigantsGrain fumigants are commonly
used around storage facilities inelevators, feed manufacturing,and food processing plants. Becauseof this, there is a tendency foremployees who work with fumigantsand fumigated materials to becomelax in their safety precautions.
ALL FUMIGANTS CAN BELETHAL if they are used care-lessly or without adequate safetyprecautions.
Phosphine and chloropicrin arehighly toxic; methyl bromide alsois hazardous to humans. There arealso physical hazards associatedwith fumigants.
Humans can be poisoned byinhaling the gases of fumigantsand by absorption through the skin(depending on the fumigant). Mostcommercial products have anunpleasant odor but the pure chemi-cals can either be odorless or have asweet smell. Also, humans maybecome insensitive to the odor of afumigant.
Continued intake of methylbromide, whether it be by inhalation,skin contact or other means, resultsin damage to body organs andtissues. This damage is not readilyapparent to the individual, especiallyin the early stages, but it is irrevers-ible and can proceed to a point wherethe person affected becomes unableto continue working. Instances areknown where the effect has accumu-lated over a 20-year period leavingthe victims in unemployable condi-tion and too old to switch to non-hazardous, lighter duty work.
All workers in areas where fumi-gants are being used or wherefumigated commodities are beinghandled should be aware of thesymptoms of light exposure to thefumigants. Such symptoms arewarnings that the concentration offumigants in the air is too high forcontinued personnel safety.
Types of
FumigantsSymptoms of FumigantPoisoning
The following are symptoms oflight exposure of chronic fumigantpoisoning:
1. Headache.2. Dizziness and equilibrium
disturbances.3. Visual disturbances.4. Irritation of respiratory tract
(leads to more “lung colds,”asthma attacks, and other lungand throat problems).
5. Narcosis (desire to sleep,drowsiness).
6. Muscle cramps—especially inarms and legs.
NOTE: The ingestion of alcoholicbeverages (from 24 hours before to24 hours after exposure) will inten-sify the symptoms and effects offumigant poisoning.
Safety Precautions
Warning Signs (Placards)Warning signs must be posted on
doors and other means of accessbefore fumigants are used in anystructure. The applicator must placeor post all entrances to the structureunder fumigation with signs (Figure15) bearing in English and Spanish:
■ The signal word DANGER/PELIGRO and the SKULL andCROSSBONES symbol in red.
■ The statement “Area and/orcommodity under fumigation,DO NOT ENTER/NO ENTER.”
Table 6.Fumigant Toxicity and Flammability
Toxicity to
Grain Flammability (ExplosiveFumigant insects Humans concentrations in air)
Phosphine High Very high Very (1.79%)*
Methyl bromide Moderate Medium Nonflammable
Chloropicrin Very high Very high Nonflammable
*Phosphine reacts with copper and copper alloys giving severe corrosion.Such metals should be protected from the gas.
48
■ The statement, “This sign mayonly be removed after thecommodity is completelyaerated (contains 0.3 ppm orless of hydrogen phosphide gas;5.0 ppm or less of methylbromide; 0.1 ppm or less ofchloropicrin). If incompletelyaerated commodity is trans-ferred to a new site, the new sitemust also be placarded if itcontains more than _______ (theamount indicated for a specificfumigant label). Workers mustnot be exposed to more than_____ (amount indicated for aspecific fumigant label).”
■ The date and time fumigationbegins and is completed.
■ Name of fumigant used.■ Name, address and telephone
number of the applicator.Warning signs must not be
removed until the treated commodityor structure is aerated to the desig-nated safe level for entry. To deter-
Types of
Fumigantsmine whether aeration is complete,each fumigated commodity, structureor vehicle must be monitored andshown to contain the designated safelevel of gas or lower.
Security GuardsSecurity guards may be necessary if
the structure is at an exposed locationwhere the public (especially children)may attempt unauthorized entry.Security guards also may be needed ifplant operations do not permit thesecurity of the fumigated area.
Guards must have the authority torefuse entry to anyone not wearingprotective equipment. They shouldhave suitable protective equipmentavailable if an emergency requiresentry into the fumigated area. Theyalso should be trained in first aidprocedures for fumigant poisoningand have the appropriate materialsreadily available.
PrecautionsPrecautions include an accounting
for all personnel known to be work-ing in the area, a room-by-room andfloor-by-floor check to ascertain thatno person has been overlooked andthe use of a portable public addresssystem (bull horn) in each space towarn anyone present of the imminentfumigation. If bells, whistles or otherdevices are used to give warningsignals, all personnel must have beeninstructed as to the meaning of thesesignals.
Doors, windows and other pointsof access must be locked or otherwisesecured against accidental or unau-thorized entry into fumigated areas.Preferably there should be oneperson ultimately responsible forevacuating all people, securing theaffected area and restricting accessuntil the area has been cleared of thefumigant.
Notices of fumigated areas must beprovided to night watchmen, janitors,maintenance crews and others whohave master keys and ready access intothe fumigated area. None of theseshould enter a fumigated area exceptin an emergency, and then only withadequate protection.
DANGERPELIGRO
AREA AND/OR COMMODITY UNDER FUMIGATION, DO NOTENTER/NO ENTRE
This sign may only be removed after commodity is completelyaereated (contains 0.3 ppm or less phosphine gas). If incompletelyaereated commodity is transformed to a new site, the new site
must also be placarded and workers must not be exposed to morethan 0.3 ppm phosphine.
FUMIGATION WITH
Brand Name:
Fumigation Being Performed By Date of Fumigation Emergency TelephonesNAME: Date Applied , 19 Day:
ADDRESS: AM PM Night:
Do not open , 19
Before AM PM
Figure 15
49
The following EPA statement isrequired:
Fumigated areas must beplacarded on all entrances with signscontaining at least the signal word“DANGER” and the skull &crossbones and the words “Areaunder fumigation, do not enter untilcompletely aerated,” the date offumigation, name of the fumigantused, emergency telephone numberto contact and the name and addressof the fumigator. Do not removewarning signs until the fumigatedarea is completely aerated and safefor entry, as indicated by a suitabledetector.
Other prefumigation precautionsare:
1. All possible sources of fire mustbe eliminated. Turn off all pilotlights, gas burners, oil burnersand electrical equipment.
2. If possible, provide for the startof post-fumigation ventilation bycontrols outside of the fumigatedarea.
3. If several floors or rooms areinvolved, rehearse the fumiga-tion sequence so everyone knowswhere the others are and whereto exit the area.
4. Discuss emergency plans forhandling all possible problems.
5. Locate a nearby telephone for usein case of an emergency.
6. Have fumigant testing equip-ment available and check it forproper operation.
7. Have first aid materials readyand available.
All areas, both those fumigatedand nearby connected buildings,must be thoroughly ventilated beforeany person is allowed to enter.Special attention must be given tobasements and pits. Some gases areheavier than air and tend to accumu-late and remain in low places wherethey can be hazardous to any humanor animal entering such places.
Types of
Fumigants
Fumigation ReferencesThere are a number of good references on fumigation and pests
controlled by fumigation. For the most current information on fumigantsand fumigation, refer to current labels and technical labelling for infor-mation on using specific fumigants effectively and safely.
Bond, E. J. 1984. Manual of Fumigation for Insect Control. FAO PantProduction and Protection Paper 54. Rome: Food and AgricultureOrganization of the United Nations, 432 p.
This publication has a very through coverage of fumigants andfumigation. It is available from UNIPUB, Inc., 4611-F Assembly Drive,Lanham, MD 20706-4391
Krischik, V., G. Cuperus and D. Galliart 1995. Stored Product Man-agement. (Revised from Management of Grain, Bulk Commodities,and Bagged Products, 1991) Circular Number E-912, OklahomaCooperative Extension Service, Oklahoma State University,Stillwater, Oklahoma. 242 p.
There are several chapters devoted to stored-product insects andintegrated pest management techniques (including Chemical Manage-ment, Practical Fumigation Techniques and Closed Loop Fumigation) inthis publication.
Mallis, A. 1982. Handbook of Pest Control. New York: Mac Nair-Dorland Company, 1101 p.
This general publication has sections on stored-product pests and agood section on fumigation.
Mills, R. and J. Pedersen 1990. A Flour Mill Sanitation Manual. St.Paul: Eagan Press. 164 p.
Stored-product pests are discussed in relation to an integratedapproach to pest management in a cereal food processing situation.
Sauer, D. ed. 1992. Storage of Cereal Grains and Their Products. St.Paul: American Association of Cereal Chemists, Inc.
This publication has chapters describing stored-product pests andvarious aspects of their control, including fumigation.
50
Types of
Fumigants Questions
1. (45) Aluminum and magnesiumphosphides involve ___ gaswhich is toxic to many forms ofanimal life.a. phosphineb. methyl bromidec. carbon tetrachlorided. ethylene bromide
2. (45) The maximum safe exposurelimit to methyl bromide gas is___ ppm.a. 2b. 3c. 4d. 5
3. (46) Methyl bromide liquid incontact with ___ may result inspontaneous ignition.a. iodized saltb. photo chemicalsc. aluminumd. sponge rubber
4. (46) Threshold limit values(TLV‘s):a. Represent the maximum toxic
levels for the pestsb. Represent the minimum toxic
level for most pestsc. Represent the conditions
believed safe for nearly allworkers
d. Represent the level of methylbromide that can be smelledby humans
5. (47) Continual intake of ___ byinhalation, skin contact or othermeans results in damaged bodyorgans and tissues.a. carbon dioxideb. nitrogenc. chloropicrind. methyl bromide
6. (47) Symptoms of light exposureto fumigants include:a. Headacheb. Dizzinessc. Irritation of a respiratory tractd. All the above
7. (48) Fumigant warning signs(placards) must not be removeduntil:a. 1 hour after fumigant
applicationb. 2 hours after fumigant
applicationc. 3 hours after fumigant
applicationd. aeration is completed
8. (48) Security guards at fumiga-tion jobs:a. Must have authority to refuse
entry to anyoneb. Should have suitable protec-
tive equipment available foremergencies
c. Should be trained in first aidd. All the above
9. (48) Precautions for fumigationinclude:a. An accounting for all person-
nel known to be working inthe area
b. A room-by-room checkto be sure nobody has beenoverlooked
c. A public address system towarn anyone present
d. All the above
51
The term ADC refers to animaldamage control. Animal damagecontrol is practiced as a field of special-ization within the wildlife manage-ment profession. In Kansas, KansasState University provides a headquar-ters for governmental assistance andadvice in animal damage problemseither from the United States Depart-ment of Agriculture, Animal, PlantHealth Inspection Service, AnimalDamage Control (USDA-APHIS-ADC),Kansas Department of Wildlife andParks and/or the Cooperative Exten-sion Animal Science Animal DamageControl program. Because of the widevariety of possible wild animal prob-lems, changing land, and changingproduct registration, we encouragepeople confronted with a problemof this nature to contact your localextension office for specificinformation.
Wild animals generally arethought of as having value, whethermeasured by economic, recreationalor aesthetic standards. However, theactivities of some wild animals canconflict with the endeavors of people.
In fact, each year rodents andbirds destroy or contaminate enor-mous amounts of stored grain. Onerat eats about 50 pounds of grain peryear, wastes twice that much, andcontaminates much more. Even aslight contamination of grain placedin interstate shipment for foodprocessing purposes causes contami-nation of the entire car load. Rodents,called commensal rodents, are theworst problem. These are the non-native Norway rat and house mouse.Rarely, the roof rat can be found inKansas. There are 23 other fieldrodents that seldom, if ever, liveindoors. One of these field rodents,the deer mouse, will sometimes befound indoors, but generally inKansas field rodents are not a prob-lem in stored grains.
Birds eat and contaminate largequantities of grain. Bird damagecontrol, like commensal rodentcontrol, is important from a healthas well as economic standpoint.
RodentsFor the purposes of this discus-
sion, commensal rodents are theNorway rat (Rattus norvegicus), roof
Vertebrate
Pests
Roof rat
House mouse Young Rat
Norway rat
Figure 16
52
rat (Rattus rattus), and house mouse(Mus musculus). Their majordiscernable characteristics are shownin Figure 16.
Inspection for nuisance rats andmice are an essential part of protect-ing stored products from loss andcontamination. Evidence of theirpresence includes:
The first step is designed to putthe rodents under maximum stress.A thorough cleaning of food, water(in the case of rats) and harborage isvery important and the degree inwhich this first step is done willdetermine the success or failure ofthe other four steps that follow. Goodhousekeeping should always bepracticed to keep food to the mini-mum and to limit places whererodents can hide and nest. But, beforeany control program is started, aneffort should be made to clean allrooms within a building. Reduceharborage outside the building byeliminating weeds, refuse piles,overgrown vegetation, and rubbishpiles. Place garbage and trash ingarbage cans and industrialdumpsters with tight-fitting covers.Eliminate as much of the rodent’swater source as possible because ratsneed water daily and mice will drinkfree-standing water if available.However, mice can survive withoutfree-standing water by obtainingmoisture from their food. Mostpeople place an overdependenceupon rodenticides when morerelevance should be placed on goodhousekeeping.
The second step immediatelyfollows the first and is the use of atoxic bait to get a rapid reduction inthe rodent population. The use of arodenticide should be secondary tostep one.
Serious consideration must begiven to the use of rodenticides infood facilities. Another considerationis the possible contamination ofstored grains and cereal products byrodenticides that could be movedfrom place to place by the rodents.In spite of these concerns, in a largepopulation of rodents, rodenticidesshould be considered.
Tracking powders are dustscontaining a rodenticide. This form ofbait is effective, particularly for micebecause rodents often groom them-selves after running through the dustand lick their feet, thereby absorbingthe toxicant. This method is notadvisable in a food facility, because
Vertebrate
Pests
House Mouseaverage length 1⁄4 inch
Norway Rataverage length 3⁄4 inch
Roof Rataverage length 1⁄2 inch
American Cockroach(enlarged)
(Blunt)
(Pointed)
(Pointed)
Ridges
Figure 17
■ seeing the animals,■ rodent noises,■ rodent droppings,■ runways,■ tracks,■ chewed or gnawed materials,
and■ odors.Rat and mouse feces are one of the
best indications of their presences.Rat, mouse and larger cockroachdroppings are shown in Figure 17.
Control TechniquesThere is no simple, fool-proof way
to control rodents in stored grainfacilities. A five-step approach torodent control seems to work best.Step one should always be followedby two, three, four and five in thatorder.
Refuse containers on racks eliminate afood source for rats.
Figure 18
53
Vertebrate
Pestsbait can be used. Place bait in safe,secluded areas where rodents arefrequenting. Proper placement of baitis important. Put out bait at closeintervals. Underbaiting is one of themost common mistakes in rodentcontrol. Use bait forms that are bestsuited for the particular conditionssuch as wax bait blocks for dampareas, cereal bait where bait securityis important, and tracking powderswhere competitive foods are abundant.
Follow label directions and usetamper-proof bait stations. Store allrodenticides in dry, locked compart-ments and where chemical contami-nation will not occur.
of possible contamination. Rodentscan carry powders throughout thebuilding.
It is the applicator’s responsibilityto choose the right bait to fit thesituation. The bait will need to beused safely and will need to beaccepted and consumed by therodents. Pre-baiting becomes impor-tant. Generally, in stored productareas, it is difficult to get rodents toeat the baited rodenticides, becauseof the high quality food they havebecome accustomed to. Therefore,the bait to be used should be placedwithout the toxicant added to test tosee if the rodents will accept the bait.If they do, then the rodenticide-laced
Figure 19
White painted band (12 inches wide) makes inspection of rodent signs easier andreminds personnel not to store commodities near walls.
Permanent bait stations.
Figure 21
Examples of commercially manufactured rodent bait stations.
Concrete can be used to preventrats from burrowing underfoundations.
Figure 20 Figure 22
54
Vertebrate
PestsThe third step is the establishment
of a continuous baiting program.Incoming rodents will soon re-establish the former rodentnumbers. This is especially trueunless improved housekeepingpractices are imposed. When bait isused, it should be used in bait boxesthat are well marked and locked.Fresh bait should be kept in constantsupply in the stations. The stationsshould be placed outdoors, next tothe building and near entry sites andindoors along the walls. Some goodrules to remember are:
■ Use locked bait stations toprotect against unsuspectingpeople and other animals.
■ Note location of all bait stations.■ Note the rate of bait
consumption.■ Pick up all dead rodents with
gloved hands and destroy thecarcasses by burning.
■ Replace moldy, wet or cakedbait with fresh bait.
Norway rats burrow into the soiland these burrows can be fumigatedto kill the rats. Read and follow labelinstructions for using fumigants inburrows, along foundations, and/ornear the building infested with rats.
The fourth step is the use of traps.Traps have a definite place in rodentcontrol activities. In food handlingbuildings, traps often are recom-mended. Trapping often is necessaryin removing bait-shy rodents. Themost common trap is a snap-trapwith a wooden base. Multiple-catchtraps are popular in food handling
buildings. Good baits for catchingmice with snap traps are:
- bacon,- peanut butter,- gum drops,- chocolate candy,- fresh bread, or- apples.Traps near a wall should be set at
right angles to the wall, with thetrigger end toward the wall. It is anadvantage to change baits frequently.
Snap traps for rats can be unbaitedif the triggers are modified. This canbe accomplished by gluing a 11⁄2-inchsquare of cardboard securely to thetrap trigger. The expanded triggertrap must then be placed in the rat’snormal path. Camouflaging withstraw or other material may help.Cage or live traps are used forcatching rats. It is important to setout a sufficient number of traps.Usually no more than 20 percent ofthe traps set in a single night may beexpected to catch rats. Because ratsbecome “trap wise” in a short time,trap locations need to be changedfrequently.
Multiple catch traps, generallyused to catch mice, need to bechecked on a regular basis. Thesetraps should be cleaned and tuned asthey are subject to damage to thespring mechanism. Human odor isnot a factor in trapping rodents.
Glue boards have become popularin rodent control over the recentyears. Very sticky material is placedin plastic traps or on cardboard andthese are placed in the rodent’s
Figure 24
concrete
sheet metal
Openings can be sealed with sheetmetal, concrete, or similar materials.
Figure 25
A trap trigger can be extended with apiece of cardboard.
The double set increasesyour success.
Double set placed parallelto the wall with triggers tothe outside.
Single trap set with triggernext to wall.
Figure 23
55
Vertebrate
Pestsnormal or forced pathways. Onceentrapped, the rodent and glueboards are both discarded.
The fifth step is rodent proofing.Rodent proofing becomes nearly asimportant as the first step. Each placepresents a different situation forconsideration. Remember that theexterior of the structure needs to bechecked for all accessible entries forrodents. Those places must bepermanently closed or protected withscreens or grating. The interior of thebuilding must have no dead spaces,such as double walls, ceilings, sub-floors, little used rooms, staircases, orboxed-in piping where rats mightfind safe places to hide and/or nest.Rodent-proofing generally requireswell-designed plans with solidconstruction using steel and concrete.Curtain walls may be used to protectotherwise vulnerable foundations.Openings for pipes, wires, etc.,require permanent seals—usuallymetal or concrete. Ventilator screensshould have holes no larger than 1⁄4 ofan inch in diameter.
In spite of all precautions, somerats and mice may get into buildings.If these rodents meet good house-keeping restrictions, the rodents willfind themselves unwelcome.
Bird Damage ControlThe three kinds of birds that areinvolved in most damage near storedproduct facilities are:
■ starlings,■ European sparrows, and■ Feral pigeons.None of these species are native
to North America and they competewith native species of birds.
Starlings are black, light-speckled,robin-size birds with a chunky,meadowlark shape. The bill of bothsexes is yellow during the reproduc-tive cycle (January to June) and darkat other times. Juveniles are palebrown to grey. The tail is short, andthe wings have a triangular shapewhen outstretched in flight. Starlingflight is direct and swift, not risingand falling like many blackbirds.
Sparrow roosts in rural and urbansites cause:
■ health,■ filth,■ noise, and■ odor problems.Their droppings damage and
deface equipment and vehicles. Inaddition, sparrows compete for nestsites with native hole-nesting birdssuch as bluebirds, flickers, wood-peckers, and purple martins.
Pigeons may carry:■ pigeon ornithosis (psittacossis),■ Newcastle disease,■ aspergillosis,■ pseudotuberculosis,■ pigeon coccidiosis,■ toxoplasmosis,■ encephalitis, and■ Salmonella typhimurium.Except for the last three, these
diseases rarely infect humans, butmay be serious if not diagnosedpromptly. Salmonella is found inabout 2 percent of pigeon feces andis statistically the most frequentcause of salmonella food poisoningin humans.
Histoplasmosis and cryptococosisare systematic fungus diseases thatmay be contracted by cleaning updusty bird manure. Bird ectopara-sites—bugs, fleas, tick and mites—frequently invade homes from birdnests in or on buildings and transmitdiseases by biting. Some bites causewelts and skin infection.
Bird droppings deface and acceler-ate deterioration of buildings andautomobiles and land on unwarypedestrians. Bird feces can contami-nant grain destined for humanconsumption. Nests may clog drainpipes, interfere with awnings andmake fire escapes hazardous.
European birds need shelter forcover, roosting and nesting. The kindof shelter depends on the season, thespecies and the reason for seekingshelter. When birds roost or nest ininappropriate places, denying accessto roost sites also will discouragefeeding.
Figure 28
Starling
Figure 26
House Sparrow
Figure 27
Pigeon
56
Vertebrate
PestsWhen birds nest in inappropriate
places, be persistent about removingnests; birds will keep trying toreestablish them in the same place.A longer term solution is to excludebirds from an area or make it lesscomfortable.
The limitations of known animaldamage control measures to controllarge-scale bird problems, make itnecessary to understand populationcontrol as a management technique. Ingood habitats abundant animal speciesrecover quickly from the loss of indi-viduals. Animal populations respondwith increased birth and survival ratesand decreased emigration. These areknown as compensatory responses.Increased immigration may followremovals, and some animals learn toavoid control efforts.
The most effective way to controlproblem birds is to understand theirdaily requirements, and remove orexclude these. This kind of manipula-tion for purposes of increasing ordecreasing numbers is an importantpart of wildlife management. Somebasic principles provide a back-ground for understanding how tocontrol problem birds effectivelyand appropriately.
To survive, all wild animals needhabitat, which is comprised of fouressential elements: space, food,shelter and water. Wildlife managersmanipulate these elements to attractand maintain wildlife species andcontrol problem species.
Space is the area needed by a wildanimal. Just as some people arehappy in a city apartment whileothers need a sprawling ranch, somebirds need more space than others. Inreference to wild animals, there aretwo kinds of space:
■ Home range—the entire areathat an animal uses to eat, sleep,and go about its daily activities;
■ Territory—that portion of thehome range an animal defendsagainst intruders, usually whereit raises young.
In most cases, the male birdestablishes and defends the territory.
In the spring, the brightly coloredmale sings to attract a mate and toannounce to other male birds of thesame species the location of histerritorial space. After the pair buildsa nest, the male continues to defendthe territory while the female hatcheseggs. This factor cannot be controlledbecause space is determined by thearea of a yard or farmstead.
Food, water and shelter areelements that can be manipulated tomanage birds in the yard or otherurban settings. Providing theseelements attracts birds; removingthem keeps them away. All areessential, yet not all bird problemscan be eliminated by just taking awayone element.
Variety is a key word in wildlifemanagement. It often is necessaryto use a variety of excluding andrepelling methods simultaneouslyto control nuisance birds.
Controlling Damage
ExclusionStructures. Where starlings are
a problem inside buildings or otherstructures, close all openings largerthan 1 inch so they cannot enter. Thisis a permanent solution to problemsinside the structure. Heavy plastic(PVC, polyvinyl chloride) or rubberstrips hung in open doorways offarm buildings have been successfulin keeping birds out, while allowingpeople, machinery, or livestock toenter. One installation approach is tohang 10-inch wide strips with about2-inch gaps between them. Suchstrips also must protect feed bunkers.Where birds are roosting on a ledge,place a board or metal covering overthe ledge at a 45˚ angle. Porcupinewires (metal protectors) also areavailable for preventing roosting onledges or roof beams. Netting also isuseful around buildings for coveringwindows or other openings.
Farm management practices areimportant in long-term starlingcontrol. These practices limit foodand water available to starlings, thusmaking the environment less attrac-tive. The following practices usedFigure 31
Rope Firecrackers
Figure 29
Shell Crackers
Figure 30
Automatic LP Gas or CarbideExploders
57
Vertebrate
Pestssingly, or preferably in combination,will reduce feed losses and thechances of disease transmission aswell as the cost and labor of conven-tional control measures:
1. Clean up spilled grain.2. When storing grain, use bird-
proof facilities.3. Use bird-proof livestock feeders.
These include flip-top pigfeeders, lick wheels for liquidcattle supplement, and auto-matic-release feeders (magneticor electronic) for costly high-protein rations. Avoid feeding onthe ground because this is anopen invitation to starlings.
4. Where possible, feed livestock incovered areas such as open shedsbecause these areas are lessattractive to starlings.
5. Use feed forms that starlingscannot swallow such as cubes orblocks greater than 1⁄2 inch in dia-meter. Minimize use of 3⁄16-inchpellets—starlings eat these sixtimes faster than granular meal.
6. When feeding protein supple-ments with other rations, suchas silage, mix them well to limitstarling access to the supplements.
7. Where possible, adjust feedingschedules so that feed exposureto birds is minimized. Forexample, when feeding once perday, such as in a limited energyfeeding program for gestatingsows, delay the feeding until latein the afternoon when foragingby starlings is decreased. Feedingcattle at night, where appropri-ate, is another possibility. Star-lings prefer to feed early tomidday and in areas where feedis constantly available. Feedingschedules that take these factorsinto account reduce problems.
8. Starlings are especially attractedto water. Drain or fill in unneces-sary water pools around live-stock operations. Where feasible,livestock waterers can be madeunavailable or less attractive tostarlings by controlling the waterlevel. Lower the water level sostarlings cannot reach it when
perching on the edge of thewaterer. At the same time, keepthe water level deep enough sothey cannot stand in it.
9. Modify starling roost sites byclosing openings in buildings orother structures so starlingscannot enter.
FrighteningFrightening devices include
recorded distress or alarm calls, gas-operated exploders, battery-operatedalarms, pyrotechnics (e.g. shell-crackers, bird bombs), chemicalfrightening agents (see Avitrolbelow), lights (for roosting sites atnight), bright objects, and othernoisemakers. Beating on tin sheetsor barrels with clubs also scaresbirds. Some novel visual frighteningdevices with potential effectivenessare eye-spot balloons, hawk kites,and mylar reflective tape. Ultrasonic(high frequency, above khz) soundsdo not frighten starlings and mostother birds because, like humans,they do not hear these sounds.
Harassing birds, throughout theevening as they land, can be effectivein dispersing bird roosts if done forthree to four consecutive evenings oruntil birds no longer return. Sprayingbirds with water from a hose or fromsprinklers mounted in the roost treeshas helped in some situations. Acombination of several scare tech-niques used together works betterthan a single technique used alone.Varying the location, intensity, andtypes of scare devices improves theireffectiveness.
Two additional tips for successfulfrightening efforts: (1) begin earlybefore birds form a strong attach-ment to the site and (2) be persistentuntil the problem is solved.
RepellentsSoft, sticky repellents are non-toxic
materials used to discourage starlingsfrom roosting on ledges or roofbeams. Examples include Roost-No-More, Bird Tanglefoot and 4-The-Birds. It often helps to first putmasking tape on the surface needingprotection, then apply the repellent
58
onto the tape. This increases effec-tiveness on porous surfaces makesremoval, if desired, easier. Over time,these materials lose their effective-ness and must be replaced.
TrappingThe wide-ranging movements
of starlings, the time necessary tomaintain and manage traps, and thenumber of starlings that can becaptured compared to the totalnumber in an area, often maketrapping an impractical controlmethod. However, trapping andremoving starlings can be successfulat locations where a static populationis causing damage or where othertechniques can’t be used. An exampleis using decoy traps to removestarlings from an orchard where theyare damaging fruit crops. Decoytraps for starlings should be at least5 to 6 feet high to allow servicing andcan be quite large (e.g. 10 feet wide ×30 feet long). A convenient size is6 × 8 × 6 feet. If desired, the sides andtop can be constructed in panels tofacilitate transportation and storage.In addition, decoy traps can be set upon a farm wagon and moved to thebest places to catch starlings. To besuccessful, the trap should be placed
where starlings are likely to congre-gate. Leave a few starlings in the trapas decoys; their feeding behavior andcalls attract other nearby starlings.Decoy birds in the trap must be wellwatered (which may include a birdbath) and fed. A well-maintaineddecoy trap can capture 100 or morestarlings per day depending on sizeand location, time of year, and howwell the trap is maintained. Shouldany non-target birds be captured,release them immediately. To killcaptured starlings humanely, useappropriate procedures such as carbondioxide exposure or cervical disloca-tion (quickly breaking the neck).
ShootingThe number of starlings that can
be killed by shooting is small inrelation to the numbers of starlingsusually involved in pest situations.Therefore, shooting is not normallyrecommended.
If any toxic baits are to be used,contact a qualified person trained inbird control work for technicalassistance (e.g. contact USDA/APHIS/ADC) or the CooperativeExtension Service Animal DamageControl office at Kansas StateUniversity.
Vertebrate
Pests
59
Vertebrate
PestsQuestions
1. (51) Commensal rodents are non-native and include the roof rat,house mouse, and ___.a. Norway ratb. pack ratc. deer moused. field mouse
2. (52) When inspecting for nui-sance rodents, evidence includesa. seeing and hearing rodentsb. rodent droppings and odorc. rodent runways and tracksd. all the above
3. (52) The second step in rodentcontrol is:a. a through cleaning of the areab. the use of rodenticidesc. trappingd. screening
4. (54) The fourth step in a rodentcontrol program is thea. establishment of a good
cleaning programb. establishment of a pre-baiting
programc. establishment of a continuous
baiting programd. establishment of a trapping
program
5. (55) In rodent proofing, ventscreens should have holes nolarger than ___ inch in diameter.a. 1⁄8b. 1⁄4c. 1⁄2d. 1
6. (55) There are three kinds ofbirds that do the most damagenear stored product facilities.Which of the following is NOTone of them?a. Starlingsb. European sparrowsc. Crowsd. Feral pigeons
7. (56) To survive, all wildlife needswhich of the following?a. spaceb. food and waterc. shelterd. all the above
8. (56) Which of the survival needsof birds can NOT be controlled?a. spaceb. foodc. waterd. shelter
9. (57) Bird damage control caninclude which of the followingtechniques?a. Exclusionb. Frighteningc. Repellentsd. All the above
10. (58) Trapping birds to controldamage can capture as manystarlings per day as ___:a. 50b. 100c. 150d. 200
60
Answers to StudyQuestions
Pages 3-131. c 2. a 3. d 4. b 5. b6. d 7. a 8. d 9. b 10. b
Pages 15-171. a 2. d 3. c 4. d
Pages 19-221. b 2. c 3. b 4. c 5. c 6. c 7. a
Pages 24-261. d 2. d 3. d 4. b 5. c6. b 7. a 8. d
Pages 28-291. c 2. a 3. a 4. d 5. a 6. c
Pages 32-371. d 2. b 3. b 4. d 5. c 6. a7. b 8. c 9. b 10. c 11. b
Pages 39-431. d 2. d 3. d 4. a 5. a6. b 7. c 8. d 9. b 10. c
Pages 45-481. a 2. d 3. c 4. c 5. d6. d 7. d 8. d 9. d
Pages 51-581. a 2. d 3. b 4. d 5. b6. c 7. d 8. a 9. d 10. b
Cooperative Extension Service, Kansas State University, Manhattan
S-16 October 1996
Issued in furtherance of Cooperative Extension Work, acts of May 8 and June 30, 1914, as amended. Kansas State University, County ExtensionCouncils, Extension Districts, and United States Department of Agriculture Cooperating, Richard D. Wootton, Associate Director. Alleducational programs and materials available without discrimination on the basis of race, color, national origin, sex, age, or disability.
File Code:Entomology 4, 11 AB 10-96—5M
Donald C. CressExtension Pesticide Coordinator
AUTHORS:John R. Pedersen, Extension Specialist, Sanitation-Grain Storage/ Processing, Kansas State UniversityRandall Higgins, Extension Specialist, Entomology, Kansas State UniversityF. Robert Henderson (retired), Extension Specialist, Extension Wildlife Damage Control, Kansas State Uni-
versityCharles Lee, Extension Specialist, Animal Sciences and Industry, Kansas State University
ACKNOWLEDGEMENT:Appreciation is expressed to the following for cooperation in the Pesticide Applicator Training Program:Jeanne Fox, Ecological Specialist, Pesticide Use Section, Plant Health Division, Kansas Department of Agri-cultureGary Boutz, Administrator, Pesticide Use Section, Plant Health Division, Kansas Department of AgricultureH.P. Boles (retired), U.S. Grain Marketing Research Laboratory, Manhattan, Kansas, is acknowledged for theinsect life cycle drawings in this manual.
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