Carpet beetles and clothes
One of Minnesota's most common household insects is the carpet beetle. There are several species, but the most familiar are the black and the varied carpet beetle.
Varied carpet beetle
The brown, hairy larvae or cast skins of carpet beetles usually are found in stored woolens, carpeting, lint accumulations, cracks and corners of closets, dresser drawers, and occasionally, in stored food and cupboards. The larvae are quite active and may appear almost anywhere in the house. It is probable that every home has some carpet beetles, although finding just a few is not usually considered a problem.
Adult carpet beetles are small, oval, black, and approximately 1/8-inch long. The adult beetles feed on pollen. The larvae often feed on lint but can cause serious damage by feeding on animal fibers—wool, fur, feathers, hair, bristles, mohair—in clothing, carpeting, upholstery, and other household furnishings. They do not feed on synthetic fabrics. Carpet beetles can also be pests in dried food products, such as flour, corn meal, cereal, and other similar foods. See Insect Pests of Stored Foods, Entomology Fact Sheet FS-1000, for control information.
Housekeeping is important. Regular, thorough removal of lint eliminates insect breeding places. Pay particular attention to rugs, carpets (especially next to walls), upholstered furniture, closets, shelves, radiators (and the space under and behind them), registers and ducts, baseboards, moldings, corners, and floor cracks.
Inspect clothing and storage areas in the fall and spring for potential infestations. Also periodically check that windows and airducts are properly screened to help prevent the entry of insects.
Dry clean or launder clothing before storing as carpet beetles are more apt to infest soiled material. Store clothing in tight boxes or chests. It is generally not advisable to use plastic bags. Although they may not harm clothing during short-term storage (several months) long-term storage could result in damage to clothing due to moisture problems or potential reactions between the plastic and the fabric.
Place mothballs or crystals (naphthalene) or part of a no-pest strip (dichlorvos) with the clothes in storage container. The smell of naphthalene may be difficult to remove from clothing. Dry clean clothing again before wearing to help remove any odor. No-pest strips may be difficult to find in stores. Cedar chips, although popular as an insect repellent, do not effectively deter carpet beetles.
Get rid of or properly store remnants or scraps of wool, fur, fleece, and other material.
Woolen garments and less expensive furs can be stored in a closet used for that purpose only. A no-pest strip hung in a closed closet will protect the garments for 3 to 4 months. One no-pest strip protects 1,000 square feet. Cut it into smaller pieces if the storage area is smaller. Do not use scissors or knives used to cut no-pest strips on food or food packaging.
If you find the larvae or their shed skins, inspect your home thoroughly. If insect numbers are low, you generally can handle the control yourself. However, local pest control operators have the experience, training, and equipment to do an effective job when excessive numbers of insects over a large area are present.
If you tackle the job yourself, start with a thorough search—
- of stored woolens in chests, boxes, and closets;
- of remnants of flannel, wool, fleece, or felt in closets, attics, and basements;
- under covers of upholstered furniture;
- in lint that accumulates in floor cracks, registers, or cold air ducts;
- under rugs, carpets, and pads—especially around edges or under seldom-moved furniture;
- under baseboards, moldings, and trim.
If the infestation is localized, remove infested material possible. Carpet beetle larvae and eggs can be killed by placing infested items in freezing temperatures for 48 hours. Clothing can also be dry cleaned or ironed. Then apply a suitable insecticide to the storage area surfaces.
If the trouble is spread throughout the building, clean thoroughly and apply an appropriate insecticide. Various insecticides are available to the public as ready to use aerosol sprays, including 0.5% chlorpyrifos, 0.2–0.5% permethrin, 1.0% propoxur, 0.1–0.25% allethrin by many manufacturers, including Black Flag, Ortho, and Raid.Read all insecticide label directions carefully!
Those wishing to use a professional service can contact a pest control operator as they have a wider range of products to choose from.
Apply the spray to baseboards, closet corners, and carpet edges. If the infestation is heavy, loosen and turn back the carpet edges and spray both sides. Since some chemicals can stain certain carpets, always test chemicals on a small inconspicuous part of the carpet before extensive spraying.
If upholstered furniture is infested, have it fumigated by a professional or, in winter, put the furniture outside in temperatures of zero or below for at least 48 hours.
Clothes moths are well-known pests of fabrics in the home. Two species of clothes moths commonly infest woolens and other animal fibers.
Casemaking clothes moth
Both the webbing clothes moth and the casemaking clothes moth are similar in appearance. The adult moths are uniformly yellowish or buff in color and approximately 1/4-inch long. They have a fluttery flight and tend to avoid light. Fully grown larvae are 1/2-inch long and white with brownish-black heads. They spin a silken feeding tube or hard protective case in the fabrics on which they feed.
The Indian meal moth, a common house-infesting moth, often is confused with the clothes moth. However, it does not attack clothing but rather is associated with dried food. Indian meal moth adults are darker on one half of the body. See Insect Pests of Stored Foods, Entomology Fact Sheet FS-1000, for identification and control information.
The adult clothes moth lays its soft, white eggs in the fabric it attacks. The eggs hatch into creamy-white larvae. The larval stage is the only feeding stage in the moth's life cycle. Approximately four generations per year occur under household conditions.
Most clothes moth infestations in homes are carried in on carpeting, woolen goods, furniture, and other home furnishings. Used household items should be thoroughly sunned before being taken into the home.
Winter clothing should be dry cleaned and stored in clothing cases or chests between cold weather use.
In general, control and prevention measures for carpet beetles also will control clothes moths.
Before using any insecticide, read the label. When using any insecticide, be careful! Avoid spilling on clothing or skin. Wash thoroughly with soap and water after spraying. Do not contaminate food, dishes, or utensils. Be sure to store all chemicals in a safe place where children cannot come in contact with them.
Jeffrey D. Hahn and Mark E. Ascerno