Expert: George Manning - 11/23/2008

Question
Thank you so much for taking the time to answer my question.  I believe we have a major problem with moths.  I dry cleaned all my cashmere and wool sweaters last winter and when I went to pull them off of their original dry cleaning plastic wrapped hangers a few days ago (I know I should have put them in air tight containers) all 5 of them were DEVOURED with at least twenty holes eaten out of each them.  I sadly had throw each sweater away.  Why did they eat them even though they were dry cleaned?  They even ate a cashmere sweater and an angora wool sweater I had hanging in the closet with stuff I wear regularly.  This puzzles me too since this closet is used several times a day and has regular air flow in and out and between garments.  Plus, our cotton duvet cover, a crib sheet, and pair of cotton sweatpants have turned up with holes too (don't know if these are from moths or coincidental bleach holes).  I'm afraid we'll get eaten out house and home.  Can a pest control company help me resolve this frustrating problem?  What can i do to prevent it from happening again?  Thanks again for your kind help.

Answer
Carpet beetles may be your problem.  They often infest cotton materials.

I am enclosing information that should help you.

I an doing this rather than writing details for you, since I found you in the question pool, which is directed to all the experts.


Carpet Beetles and Clothes Moths
Darryl P. Sanders
Department of Entomology

Carpet beetles
Carpet beetles belong to the beetle family Dermestidae. The adults are harmless and feed on plant pollen exclusively. It is the larva (growing stage), that causes damage by feeding on items primarily of animal origin. Carpet beetles will also attack other materials, such as cotton and synthetic fibers if these fabrics are soiled with human perspiration, body oils, beer, milk or fruit juice. Some carpet beetles may become "pantry pests" by invading cereal grain products.



Figure 1
The adult black carpet beetle, top, and larva.


Black carpet beetle
The black carpet beetle, Attagenus unicolor (Figure 1), is the most destructive and widespread carpet beetle in the United States. Adults are black with brown legs, somewhat shiny, oval and about 1/8- to 3/16-inch long.

The larva is brown and carrot-shaped with a long brushy tail of brown hairs, and up to 1/2-inch long at maturity.

Black carpet beetle larvae will eat almost anything of animal origin, such as wool, hair, feathers, leather, furs, stuffed trophy animals, dead insects or silk. They may also feed on cereal grain products and nut meats. Development from egg to adult beetle takes from nine months to two years.

Varied carpet beetle
The varied carpet beetle, Anthenus verbasci, is the most commonly encountered carpet beetle in Missouri. The adult beetle is a rounded oval, convex and about 1/8-inch long. The wing cover surface is patterned with brown, yellow and white scales. The ventral surface of the body is covered with fine, long grayish scales. Larvae are approximately 3/16-inch long at maturity.

They appear to be composed of a series of alternating light and dark brown transverse stripes. They are very fuzzy and have three pairs of dark brown bristly bundles located somewhat laterally on the segments near the rear end.

Varied carpet beetle larvae feed on anything of animal origin, as described for the black carpet beetle. They are also often associated with abandoned bird nests. Development time takes from nine months to one year.

Other species
Other species found less often in Missouri homes include the common carpet beetle, Anthrenus flavipes. Both species are very similar in appearance and feeding habits to the varied carpet beetle.

Clothes moths
Clothes moths belong to the moth family Tineidae. The larval (caterpillar) stage damages items of animal origin, such as wool, fur, silk and feathers. The adult moths do not feed. They are rarely seen because they tend to hide in the dark during daylight. The Indian meal moth, a common "pantry pest," flies about during daylight and is often mistaken for one of these moths.

Casemaking clothes moth
The casemaking clothes moth, Tinea pellionella, is a buff gray color and approximately 1/4-inch long with its wings folded along the body. Each front wing has three somewhat indistinct darker spots of scales.

The larva is creamy white with a brown head. It produces a silken tube-like case in which it lives and carries around for protection. The head and legs are exposed only during feeding and movement. This case is camouflaged with bits of the material on which the larva has been feeding. The larva is approximately 1/2-inch long at maturity.

Development from egg to adult is highly variable, depending upon available food and environmental conditions. It may be as little as a month.

Webbing clothes moth
The webbing clothes moth, Tineola bisselliella, is a uniform buff color, approximately 1/4-inch long. It has a small tuft of red hair on the top of its head.

The larva is whitish colored with a brown head. It produces a silk-lined "tunnel" as it eats through or on the surface of a fabric. The moth is approximately 1/2-inch long at maturity. Its developmental time is very similar to that of the casemaking clothes moth.

Control measures
Prevention
Vacuum wool carpets often enough to prevent the accumulation of hair, lint and other carpet beetle food materials. Remember to vacuum under seldom-moved furniture and along baseboards. Upholstered furniture, air ducts and other lint-accumulating sites also need this cleaning.

Dry clean or launder woolens and place them in tightly sealed containers for summer storage. Moth balls (naphthalene) or PDB (paradichlorobenzene) crystals may help prevent carpet beetles and clothes moths from invading the articles. Use paper to avoid direct contact between chemical and the articles. Avoid long-term and undisturbed storage of susceptible materials.

Help deter carpet beetle invasion by removing abandoned bird nests and bee and wasp nests from attics, wall voids and eaves. Remove dead insects in light covers, window sills or other places of accumulation to avoid carpet beetles.

Chemical control
Spray infested carpet or upholstered furniture with a light mist, to the point of dampness, or dust with one of the insecticides listed in Table 1. Do not spray clothing, just the cracks and crevices of the clothing storage area.

Table 1
Insecticides for carpet beetle and clothes moth control.

Insecticide Application concentration
Spray Dust Remarks
Bendiocarb (Ficam)   1 percent Difficult to find except in pest control operators (PCO) supply stores
Boric acid   1 to 99 percent Many formulations on market
Chlorpyrifos (Dursban) 0.5 percent 1 percent Dust sold as OrthoKlor Ant Killer Dust
Cyfluthrin (Tempo) 0.05 percent   For use only by PCOs
Diazinon 0.5 percent     
Lambda-cyhalothrin (Commodore) 0.15 percent   For use only by PCOs
Permethrin (Flee) 0.5 percent   For use only by PCOs

When treating rugs that are not fastened to the floor, treat both top and bottom surfaces. These pests like undisturbed locations, so treat all carpet under furniture and the under side of upholstered chairs and couches. In the case of wall-to-wall carpeting, be sure to treat along all baseboard-to-carpet contact areas.

Ready-to-use aerosol sprays containing insecticides, such as allethrin, resmethrin, tetramethrin and pyrethrins may also be used to spray carpet, upholstered furniture and stuffed toy animals. Stuffed animal trophies may require an additional internal spray or dusting. Use a crack and crevice injector to spray inside or a puff duster to inject an insecticidal dust, such as boric acid, bendiocarb (Ficam), carbaryl (Sevin) or chlorpyrifos (Dursban).

Do not allow children or pets into the sprayed areas until the treated surfaces are thoroughly dry. Dusts used in open areas should be left for a few days and then vacuumed up before children or pets are allowed in the area.

Staining or running of colors is a possibility with certain fibers. Test a small, hidden area with the spray product to check for any adverse effects before applying the chemical to the entire area.

G7372, new July 1994

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© 1993 to 2008 Curators of the University of Missouri, all rights reserved
University of Missouri Extension is an equal opportunity/ADA institution.


Best regards Kathy,

George Manning
Consulting Entomologist
george@pestproblemssolved.com
www.pestproblemssolved.com