pantry and fabric pests in the home - texas a&m agrilife...

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Pantry and Fabric Pests in the Home L-2046 2-02 Michael Merchant and Grady J. Glenn* F ood and fabric pests can be found in nearly every home. They are usually no more than an occasional inconvenience. If an infesta- tion develops in your home, the information in this publication should help you control it. Some insects feed primarily on plant materials and are usually found in stored foods in kitchens and pantries. Other insects feed primarily on products containing animal proteins, such as woolen fabrics, leather and hides, hair, feathers, powdered milk and some pet foods. Animal product pests are more likely to be found in closets and areas other than kitchens. Either kind of pest can be found almost anywhere in a home, however. If you find the same kind of insect repeatedly in a kitchen or closet it is good evi- dence of a pest problem. How did they get in my house? Food pests are usually brought home from the grocery or pet store. Food can become infested while in the farm or garden, or during storage or transport. While food manufacturers and grocery stores control most food pests with strict sanita- tion and the judicious use of pesticides, it is pos- sible for a few insects to make their way into your home. Insects that feed on animal products also may come into your home from the grocery store, but are more likely to enter from outdoors. Clothes moths and carpet beetles occur outdoors in bee, bird and rodent nests. Carpet beetle adults are often found on crape myrtles and other orna- mental shrubs and flowers. Should they come indoors, carpet beetles or clothes moths may lay their eggs on woolen carpets or stored fabric items. Pests of seeds, grains and spices The Indian meal moth is a common and dis- tinctive pantry pest. It is the most common pest of dried fruit, nuts, cereals and oilseeds. It also infests powdered milk, chocolate and other can- dies, bird seed and dog food. The adult Indian meal moth has wings that are whitish-gray at the base and deep pink or copper colored on the outer two-thirds. The wingspan is about 3 /4-inch. The caterpillars, or immature stage of the Indian meal moth, are often noticed crawling up walls and spinning cocoons on textured walls or ceil- ings. Inside the cocoons they pupate and become adults. *Extension Urban Entomologist; and Research Associate, Center for Urban and Structural Entomology; The Texas A&M University System. Figure 1. The Indian meal moth is the most common indoor moth pest. Adults are easily identified by their bi-colored wings. (Photo courtesy USDA) Actual size 10mm

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Page 1: Pantry and Fabric Pests in the Home - Texas A&M AgriLife ...counties.agrilife.org/fayette/files/2011/08/pantry... · tinctive pantry pest. It is the most common pest of dried fruit,

Pantry and FabricPests in the Home

L-20462-02

Michael Merchant and Grady J. Glenn*

Food and fabric pests can be found in nearlyevery home. They are usually no more thanan occasional inconvenience. If an infesta-

tion develops in your home, the information inthis publication should help you control it.

Some insects feed primarily on plant materialsand are usually found in stored foods in kitchensand pantries. Other insects feed primarily onproducts containing animal proteins, such aswoolen fabrics, leather and hides, hair, feathers,powdered milk and some pet foods. Animalproduct pests are more likely to be found in closets and areas other than kitchens. Either kindof pest can be found almost anywhere in a home,however. If you find the same kind of insectrepeatedly in a kitchen or closet it is good evi-dence of a pest problem.

How did they get in myhouse?

Food pests are usually brought home from thegrocery or pet store. Food can become infestedwhile in the farm or garden, or during storage ortransport. While food manufacturers and grocerystores control most food pests with strict sanita-tion and the judicious use of pesticides, it is pos-sible for a few insects to make their way intoyour home.

Insects that feed on animal products also maycome into your home from the grocery store, butare more likely to enter from outdoors. Clothesmoths and carpet beetles occur outdoors in bee,bird and rodent nests. Carpet beetle adults are

often found on crape myrtles and other orna-mental shrubs and flowers. Should they comeindoors, carpet beetles or clothes moths may laytheir eggs on woolen carpets or stored fabricitems.

Pests of seeds, grains andspices

The Indian meal moth is a common and dis-tinctive pantry pest. It is the most common pestof dried fruit, nuts, cereals and oilseeds. It alsoinfests powdered milk, chocolate and other can-dies, bird seed and dog food. The adult Indianmeal moth has wings that are whitish-gray at thebase and deep pink or copper colored on theouter two-thirds. The wingspan is about 3/4-inch.The caterpillars, or immature stage of the Indianmeal moth, are often noticed crawling up wallsand spinning cocoons on textured walls or ceil-ings. Inside the cocoons they pupate and becomeadults.

*Extension Urban Entomologist; and Research Associate,Center for Urban and Structural Entomology; The TexasA&M University System.

Figure 1. The Indian meal moth is the most common indoor moth pest.Adults are easily identified by their bi-colored wings. (Photo courtesyUSDA)

Actual size

10mm

Page 2: Pantry and Fabric Pests in the Home - Texas A&M AgriLife ...counties.agrilife.org/fayette/files/2011/08/pantry... · tinctive pantry pest. It is the most common pest of dried fruit,

Another pantry moth is the Angoumois grainmoth (AHN goom wah), which commonlyinfests popcorn, Indian corn decorations, andseeds in dried flower arrangements.

Cigarette beetlesand drugstore beetlesare the most commonpests of home pantriesin Texas. The larvae ofthese beetles feed onall kinds of plant mate-rial including tobacco,seeds, grain, nuts,beans, spices, cotton-seed meal, dried fruitsand vegetables, flour,potpourri and driedflower arrangements.They are strong fliersand may be attracted to lights and windows.Adults do not feed, but lay their eggs on foodsources.

Merchant beetles and saw-toothed grain beetles infestcereal and flour products, maca-roni and dried fruits. Adults areabout 1/8 inch long, brown,elongated and flattened inshape. With a magnifying glass,they can be distinguished fromother grain beetles by their sixsaw-like teeth on the margins ofthe segment behind the head.Adults of these beetles do notfly, but their flattened bodiesmake it easy for them to enterfood packages.

Rice weevils and granaryweevils are pests of wholegrain or processed grain foodssuch as macaroni. These wee-vils are cylindrical, about 1/6inch long, and have prominentsnouts. Larvae are pale, c-shaped and legless. Adults of

both species are reddish-brown to black, but the riceweevil may have four palered or yellow markings onthe wing covers. These bee-tles rarely penetrateunopened food packages.Rice weevil adults can flyand are attracted to lights.Granary weevils do not fly,but enter homes in infestedfood.

Flour beetles are also com-mon and destructive pests. Adultflour beetles are elongated, red-dish brown, and 1/8 to 3/16 inchlong. They feed on cereals,grains, beans, nuts, dried fruits,spices, milk chocolate, driedmilk and, occasionally, hides.They tend not to feed on wholegrains or intact seeds, but favorflour and other milled grainproducts. Food products infestedwith flour beetles have a foulodor and taste.

Pest of woolens,hides and feathers

Beetles in the genus Dermestesare collectively known as car-pet, hide and larder beetles.Most feed on animal proteins,though some will also feed onhigh-protein plant materials. Inthe pantry, they may be foundin powdered milk, dried meats,or pet foods that contain fishmeal or other animal byprod-ucts.

Hide beetles are a seriousproblem in museums. Theyattack leather goods, trophyheads, hides, skins, and driedfish. In the home they also feedon pet food, bacon, cheese andfeathers.

Household infestations oftencan be traced to bird or rodentcarcasses in attics, old bee nests,or accumulations of dead insectsin windows or light fixtures. When fully grown,these larvae sometimes bore into wood or otherhard substances to pupate, leaving 1/8-inch-wideholes.

Adult hide beetles are relatively large, 1/4 to3/8 inch long. They are dark brown to black,with various markings. The larvae are cigar-shaped and covered with fine hairs that givethem a fuzzy appearance. Hide and larder bee-tles in the genus Dermestes can be recognized bya pair of large, curved “horns” on the last bodysegment.

Beetles of the genus Anthrenus and the genusAttagenus are smaller than Dermestes beetles andare colorfully marked. Anthrenus and Attagenusbeetles are 1/8 to 3/16 inch long and round or

Figure 2. Drugstore and cigarettebeetles (a and b, respectively) aresimilar in appearance. Their smallsize, rounded profile and concealedhead are characteristic. (R. White,USDA)

Figure 5. The redflour beetle feeds onpro-cessed grains,nuts, fruits andmeat-based prod-ucts. Its flat shapeenables it to hide innarrow cracks andenter narrow open-ings in food packag-ing. (A.D. Cushman,USDA).

Figure 3. The saw-toothed grain beetleis a common pest ingrain-based processedfoods. It can be iden-tified, with the aid ofa magnifying lens, bythe saw-like teeth onthe edge of the shieldbehind the head. (A.D. Cushman, USDA)

Figure 6. Carpet bee-tles feed on woolensweaters, rugs, feath-ers and furs. Adultcarpet beetles arecommon outdoorsand can enter homesthrough doors, win-dows or attics.

Actual size

3mm

Actual size

2.5mm

Actual size

4mm

Actual size

3mm

Actual size

4mm

Figure 4. Weevils haveprominent snouts and areusually found in wholegrains. (Photo courtesyUSDA)

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oval. Larvae are light tan tobrownish and about the sizeand shape of small rice ker-nels. Larvae are ringed withcircular tufts of hairs, givingthem a banded appearance.Like hide beetles, infesta-tions of carpet beetles maystart in bird nests or accu-mulations of dead insects inlight fixtures. Once estab-lished inside a home thesebeetles can cause consider-able damage to woolen arti-cles, furs, feathers, hairbrushes and other valuablepossessions.

Warehouse beetles, of thegenus Trogoderma, lookmuch like black carpet bee-tles but have light brownishbands on the wing covers.They feed on both animaland plant products. BothTrogoderma and Anthrenusbeetle larvae have barbedhairs on their bodies that

can irritate the digestive tract if the beetles areaccidentally ingested.

Clothes moths feed on silk, wool, fur, feath-ers and hair. Rugs and clothing that contain thesesubstances can be seriously damaged. They alsofeed on powdered milk and products containingmeat or fish meal, such as pet food. Synthetic orcotton fabrics are attacked only if they are soiled,or interwoven with natural animal fiber materi-als. Clothes moths occur naturally outdoors. Inhomes, they may be found in accumulations ofpet hair or feeding on dead insects.

Clothes moths are secretive. The larvae preferto feed in protected places such as under cloth-ing collars or in folded sweaters. Adults also

shun light and are rarelyseen flying during the day(see box). One of the bestways to control thesepests is the old-fashionedpractice of “spring clean-ing,” or periodically shak-ing and airing rugs andwoolens outdoors in thesun. Clothes moth larvaeare very sensitive to lightand low humidity.

Controlling pantry pestsNon-chemical control. The first step in con-

trolling pantry pests is to locate and eliminateinfested foods. Removing an infested package offlour, macaroni or cake mix is often all that isneeded to solve the problem. But finding thesource of an infestation is not always easy.Infested packages are usually the oldest, mostdifficult to reach foods in the pantry. Evenunopened containers may be infested; waxedpaper, plastic and cardboard containers can bepenetrated easily by some pests. In the store,check that bags or containers are well sealed.

Infestations frequently start in spilled grains,pet foods or other foods. So, good sanitation isimportant. Keep food spills cleaned up. Vacuumand clean pantry areas periodically to removespilled foods. Remove and clean under shelfpaper, too. Discard old packages of grain andpasta. Most pantry pest problems can be prevent-ed by using all dried food within 2 to 4 monthsof purchase. Spices and other products that arekept for longer periods should be sealed in air-tight containers.

Figure 7. Immature carpetbeetles are cigar-shapedwith a banded appearance.They may be found feedingon dead insects in lights,on window ledges, or inclosets (C. Feller, USDA).

Figure 8. Clothes moths attackstored clothing. They shunlight and rarely fly. (Photocourtesy USDA)

Actual size

6mm

Actual size

5mm

Distinguishing between clothes mothsand pantry-infesting moths

Clothes moths and pantry moths can be dis-tinguished by their appearance and behavior.

� Clothes moths are smaller than pantrymoths, have narrower wings, and are moresecretive.

� Clothes moths avoid light and are weakfliers, preferring to run when disturbed.

� Cloths moths have unmarked wings with a span of about 3/8 inch (10 to 14 mm), andshiny gold scales on their bodies. With amagnifying glass you can see that the headhas a fluffy pompadour of reddish-goldhairs.

� Clothes moths are not commonly seenbecause they are active mostly at night.The larvae rarely leave their food source.

� Pantry moths, such as the Indian mealmoth, are larger, with wingspans of 1/2inch or more. They may be seen activelyflying during the day. They are usuallyfound near stored food and are more likely to be seen crawling up walls and on ceilings.

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Pet food can be a special problem. Birdseedand dog and cat foods are the most commonlyinfested pantry items. Store pet foods in well-sealed plastic buckets or storage containers anduse them promptly.

Occasionally, mice can be the cause of a per-sistent beetle infestation. Hoarded seed and grainin abandoned rodent nests can support a smallpopulation of pests. Old rodent bait that containsgrain also can harbor insects. Place rodent baitwhere it can be retrieved and discarded after useto prevent insect problems.

Heat or cold treatments can get rid of pests insome food items such as pet food, bulk grainsand beans, or home-grown dried beans or peas.Put the product in the oven at 130 degrees F foran hour, or in the freezer for 7 to 14 days. Storefoods that may attract pantry pests in the refrig-erator or freezer to prevent infestation.

Chemical control. On rare occasions, insecti-cides are needed to control difficult infestations.Insecticides can be used to treat inaccessibleareas that cannot be easily cleaned, or to helpreduce heavy pest infestations. Insecticide spraysmay be applied to crevices and void areasaround cupboards, drawers and pantries. Allfood products, utensils and containers should beremoved from the treatment area before spray-ing. Allow spray to dry before placing clean shelfpaper on the shelves and returning food items.

Insecticide products that are labeled for use infood storage areas contain ingredients that areshort-lived and relatively safe to use in the home.These ingredients include pyrethrins, resmethrin,allethrin and tetramethrin. For areas where long-term, residual control is desired, look for prod-ucts containing synthetic pyrethroids, such aspermethrin, esfenvalerate, cyfluthrin or bifen-thrin. Aerosol fog products can temporarily sup-press infestations of flying insects, but aerosolsalone will not solve a pantry pest problem.Always make sure that the label of the productyou use states that the product can be usedindoors and in kitchens.

Controlling clothes mothsand dermestid beetles

Eliminating clothes moths and dermestid bee-tles can be a challenge. As with pantry pests, thefirst step is to locate and eliminate all feedingsites. Unfortunately, there may be many points

of infestation. Check these potential problemareas:

� In drawers: folded silks, woolen blankets,felt fabrics, and leathers; natural hair artbrushes, and other susceptible materials.

� In closets: woolen sweaters, shirts andjackets (especially under the collars); furs;feather dusters or other feather items; felthats; stuffed trophies, etc.

� On the floor: woolen rugs; carpet padsmade from animal hair; pet hair accumula-tions along baseboards and under furniture.

� Furniture: old chairs or sofas stuffed withhorse hair; accumulations of pet fur.

� On walls: susceptible art objects; wool,mohair or silk draperies; trophy mounts;dried flower arrangements.

� In walls, ceilings and attics: old bird,rodent, bee or wasp nests; bird or animalcarcasses; old rodent baits; stored items;accumulations of dead insects in light fix-tures or on window sills. Previous infesta-tions of lady beetles or box elder bugs mayleave accumulations of dead insects that arefood for dermestid beetles.

� Other sites: spilled pet food in utilityrooms; old mouse nests under cabinets; dec-orations containing grains or noodles; pot-pourri, etc.

Non-chemical control. Discard infested items,or treat them and protect them from furtherattack. Clothing can be disinfested by washing ordry-cleaning. Annual or semi-annual “spring-cleaning” is especially effective in controllingclothes moths. Rugs and blankets should be beat-en or shaken vigorously and exposed to brightsunlight for a few hours. Thoroughly vacuumingstorage areas and susceptible rugs is helpful. Thebest protection for valuable stored items is toopen and inspect them frequently.

Valuable articles of clothing and other itemscan be treated by freezing them for 7 to 14 days(which is less destructive than heating if doneproperly). In general, textiles, furs, feathers,leather, paper and wood can be safely frozen.Put articles into air-tight polyethylene bags, withas much of the air removed as possible, beforeplacing them in the freezer. This reduces thechance of ice forming directly on the article andcausing damage. If you have concerns about pos-sible damage to a valuable item, contact a localmuseum with experts in the conservation of his-torical artifacts.

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Clothing that is susceptible to insect damageshould be stored in airtight boxes or garmentbags. Cold-storage is effective in protecting fursand other valuable items from attack.

Chemical control. Cedar closets, cedar chestsand pieces of cedar wood placed in storage areasmay repel insects for a short while, but do notguarantee protection. Vapors from cedar woodare effective only when the wood is freshly cutor chipped and the container is well sealed. Fewcedar chests more than 2 or 3 years old produceenough vapor to kill pests. Naphthalene andparadichlorobenzene (PBD) products are moreeffective than cedar, but must be sealed tightlywith the clothes. Use 1 to 2 pounds of repellentper 100 cubic feet of air to kill moth larvae. Thefumes from PDB crystals will soften or melt cer-tain plastic products, so be careful using themwith plastics.

Insecticide sprays can supplement good sanita-tion and other measures. Spray around windowsand light fixtures to help keep pests out of thehome. Closets with carpet beetle or moth infesta-tions may also be treated. Remove clothing firstand let the spray dry before putting items backin the closet. Sprays also can be applied alongthe edges of carpets where pet hair and insectsaccumulate, or on the undersides of carpets orcarpet pads. Because most clothing pests are notout in the open, aerosol insecticides (“bombs”)are not very effective. Aerosols cannot penetrateinto the pests’ hiding places. Getting help from apest control professional is often the best choicefor controlling carpet beetles and clothes moths.

MonitoringSome pests can be detected with pheromone

traps and other devices. Pheromones are specialhormones that insects produce to communicatewith one another. There are pheromone lures forseveral storage pests, including the cigarette bee-

tle, drugstore beetle, Indian meal moth,Angoumois grain moth, warehouse beetle andwebbing clothes moth. Pheromone traps do notcontrol pests, but they can help you detect infes-tations and pinpoint problem areas. Pheromonetraps are generally most effective for flyinginsects.

Other traps, such as the FLITe-TRAK® andPantry Patrol™ traps, use food or other attractantsin addition to pheromones to lure pests. Thesetraps are useful in kitchens and pantries and areavailable from the manufacturers or from pestcontrol professionals.

Sticky traps are useful for monitoring the suc-cess of your control program. They are availablethrough pest control companies, do-it-yourselfpest control shops, and some grocery stores.Sometimes sold as roach “hotels,” sticky trapscontain a glue that captures crawling insects.When placed on the closet floor or on closetshelves, they trap dermestid beetles.

Figure 9. Insect sticky traps catch crawling insects and can help pin-point the source of an infestation. Place traps next to a wall or beside acabinet for best success.

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Produced by Agricultural Communications, The Texas A&M University SystemExtension publications can be found on the Web at: http://texaserc.tamu.edu

Educational programs of Texas Cooperative Extension are open to all people without regard to race, color, sex, disability, religion, age or nationalorigin.Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, andJune 30, 1914, in cooperation with the United States Department of Agriculture. Chester P. Fehlis, Deputy Director, Texas Cooperative Extension,The Texas A&M University System.10M, Revised