Carpet beetles are found throughout Virginia and occur in both clean and cluttered dwellings.
The four most important and most common species are the black carpet beetle (Attagenus mezatoma) shown here, the varied carpet beetle (Anthrenus verbasci), the common carpet beetle (Anthrenus scrophulariae), and the furniture beetle (Anthrenus flavipes). The adults feed primarily on pollen and nectar and can be found on outdoor plants during the summer. The adult stages of carpet beetles are small, oval insects, usually less than 1/4 inch long. Carpet beetle larvae are usually about the size of the adult beetle, 1/4 inch or less in length but they have dense tufts of long setae (bristles) on their bodies. Black carpet beetle larvae have a long tuft of hair at the end of their bodies. Adult carpet beetles are commonly found indoors at windows. Carpet beetle larvae often wander about the infested location-- from room to room in a house. This behavior results in spreading the infestation throughout the house.
All of these beetle species have a complete life cycle--egg, larva, pupa, and adult. Adults can mate and reproduce without feeding. Females can lay from 30 to 100 eggs, depending on the species. Eggs are laid in lint, behind and under baseboards, in floor cracks, or other dark and protected locations. Eggs hatch in one to three weeks. Larvae develop over a 3 to 36 month period and can molt (shed their skin) from 5 to 12 times. The pupal stage lasts 6 to 24 days, but the adult may take up to three weeks before it emerges.
The larval stages cause damage to a variety of material. Their preferred food varies with the species, but all carpet beetle larvae can feed on wool carpets and other wool products, furs, hides, horns, feathers, hair, and silk. They will also feed on linen, cotton, and rayon if these fabrics are soiled with juice, food, or animal excreta. They can be pests in cereals, stored grains, nuts, meal, Indian corn, red pepper, and similar products. Carpet beetle larvae are frequently pests of insect collections and other museum specimens.
Look for and discard infested material. Check all types of wool, hides, dried meat, dried foods, stored candy, and under wool carpets. Vacuum regularly where found and use moth crystals or flakes when storing wool. Carpet beetles may be coming from an abandoned bird or bee/wasp nest or from a dead mouse or squirrel in a wall. In addition carpet beetles feed on dead dried insects that collect in window frames.
The old skins are often mistaken for live larvae, and can give the impression of a larger infestation than really exists.
Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.
Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Interim Administrator, 1890 Extension Program, Virginia State University, Petersburg.
May 16, 2011