Common Household Pests: Carpet and Hide Beetles
||Adult carpet and hide beetles common in Utah homes: (top left) Trogoderma sp., (top right) larder beetle (Dermestes lardarius), (bottom left) varied carpet beetle (Anthrenus verbasci), and (bottom right) black carpet beetle (Attagenus brunneus). Adult beetles are small, ranging in size from 2 mm to 10 mm.
||Immature dermestid beetles (larvae) can grow up to 13 mm in length depending on the species, and can be mistaken for duff millipedes or other immature insects. Have your larvae identified to discern which insect is present.
Behind aphids, the most frequently submitted insects to the Utah Plant Pest Diagnostic Lab (UPPDL) are the carpet and hide beetles in the family Dermestidae. Dermestids are some of the most common and damaging household pests in the United States, feeding on a range of food, including leather, furs, feathers, hides, museum specimens, dead insects, woolen or silk rugs and textiles, stored food products, dead animal flesh, shed hair (human and pet), and occasionally cotton or linen.
Today, the name “carpet beetle” is largely outdated and misleading. Historically, carpets were made from animal products such as wool and were fed upon by larvae of certain dermestid species. Today, however, carpets are mostly made from synthetic materials, which are not readily consumed by carpet beetle larvae. In some situations, though, larvae can feed on synthetic textiles if they possess contaminants of nutritional value such as urine, perspiration, or food stains.
Adult beetles usually enter homes on fresh-cut flowers, through open doors or windows, or are introduced via infested food products like grains or flour. People are often concerned when they find a dermestid beetle in their home; however, finding a few beetles indoors does not mean that an infestation is present. Adult dermestid beetles are common outside where they feed on pollen and nectar of plants, while larvae are frequently found scavenging high-protein substances such as dead insects, decaying animal or plant material, or feeding in bird, mammal, bee or wasp nests.
Of the 123 species occurring in the U.S., 12 species from five genera have been identified by the UPPDL from Utah homes. The most common Utah dermestids include the varied carpet beetle (Anthrenus verbasci), black carpet beetle (Attagenus megatoma), larder beetle (Dermestes lardarius), hide beetle (D. maculatus), and the warehouse beetle (Trogoderma variabile).
Indoors, dermestids are commonly found in the pantry, kitchen, bathroom, or in window sills. If large numbers of beetles are found, control measures should be taken to limit damage. The following steps
can eliminate a dermestid infestation from homes:
1. Identify beetles. Given the long list of dermestid food, understanding the feeding habits of the pest beetle can help create a targeted inspection.
2. Locate beetle source. The key to eliminating dermestid beetles is to find where the larvae are feeding. Stored foods, animal hides/ materials/textiles, under carpeting, baseboards, and furniture, under seat cushions of upholstered furniture or anywhere hair, lint, dead insects, food crumbs, etc., collect are prime areas. Areas of minimal use such as attics, basements, cubbies, under unused or seldom moved furniture or appliances, etc., are also prime locations. Remember to search for both larvae and adult beetles.
3. Eliminate infested products. Once the infestation is located, remove infested items from the home. Infested clothing can be dry-cleaned or washed. Infested food should be discarded. Some dermestid larvae have many arrow-shaped hairs (hastisetae) which can cause irritation of the digestive tract. Options for non-food items include:
• freeze for 2 weeks at temperatures below 18° F
• heat treat for at least 30 minutes at 120° F
• fumigate in sealed container using a resin strip (dichlorvos).
4. Clean and vacuum. Thoroughly clean the area of infestation. Make sure to vacuum all adult and immature beetles to prevent future infestations. Discard vacuum bag after cleaning.
5. Properly store food. Store all newly purchased food items (primarily bulk items) in air-tight, insect-proof containers. Susceptible clothing or textile items should also be properly stored.
6. Exclude beetles. Keep dermestids out of the house from the start by using screens and weather stripping to secure windows and doors, and appropriately sealing insect entry ways into the home.
Insecticides can be used to augment a thorough inspection, cleaning, and exclusion program where dermestids are infesting non-food products. For insecticidal control of dermestids, consider the following:
1. Treat cracks, crevices, and voids with inorganic dusts such as silica aerogel or diatomaceous earth; pyrethroid dusts may also be used. Areas under carpet edges in infestedrooms can also be treated with an insecticidal dust.
2. Spot treatments with liquid or aerosol pyrethroid insecticides (bifenthrin, cypermethrin, deltamethrin, permethrin, tetramethrin, etc.) may be needed; avoid broadcast applications. Some insecticides may stain or discolor carpets, rugs, and textiles; test products on target material before applying.
3. For tough-to-clean or larger items, mini-fumigations can be performed using resin strips (dichlorvos) in a sealed garbage bag or other air-tight container.
4. When storing susceptible items, use moth balls, flakes, or crystals that contain naphthalene or paradichlorobenzene (PDB) or resin strips; avoid direct contact of these materials with plastics as they can soften and melt into fabrics.
5. Carefully read and follow the information on the product label for safe and legal use.
6. Homeowners should consider hiring a pest control professional to help in managing a dermestid infestation.
-Ryan Davis, Arthropod Diagnostician
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Mallis, A. 2004. Handbook of Pest Control. Ninth Edition. GIE Media Inc.
Rust, M., et al. 2001. Carpet Beetles. IPM Education and Publications, University of California Statewide IPM Program.