Carpet Beetle Larvae

Carpet Beetle Larvae

Several species of carpet beetles including black carpet beetles, varied carpet beetles and furniture carpet beetles are commonly found in homes in Colorado as well as in wild populations.  Although minor occurrences of these beetles are not usually of concern, experiencing a severe infestation may require the assistance of a pest control professional.  Carpet beetles are known for infesting stored food products, taxidermy displays, wool fabrics, feathers and other items with an animal origin.  While it is the larvae that feed on animal based items, adults feed on pollen from plants.  The common name of this group of beetles originates from the wool carpets they once infested.  Synthetic carpets common in homes now are not a source of infestation.  Household infestations are suspected to be a result of wild populations or transported into the home on items that are already infested.

Adult carpet beetles are roughly 1/8 of an inch in length, although size may vary slightly depending on the species.  Coloration depends on the species; black carpet beetles are a shiny dark-brown to black, while other species are covered in scales of various colors and patterns. Female carpet beetles lay eggs for a period of approximately two to three weeks in areas where accumulations of lint and/or dead insects occur, under baseboards, along the edges of carpeting and other locations.  Hatching time varies from 10 to 20 days, at which time emerging larvae seek a food source.  Larvae are mobile and may wander from their hatching site in search of food.  Carpet beetle larvae are elongated and covered with short hairs.  Coloration varies from light brown to a reddish-brown.  Some species have a distinctive tuft of hairs that protrude from their back end.  Larvae continually shed their skins, which are often mistaken for live insects.  Although larger in size at approximately 1/8 of an inch, larvae may resemble duff millipedes in appearance. Depending on environmental conditions including temperature and the quality or availability of food development times range from 2 to eleven months on average.  When food sources are removed or diminished, larvae are capable of surviving several weeks without food.  Indoors a majority of carpet beetles have a life cycle of roughly one-year.

Varied Carpet Beetle

Varied Carpet Beetle (Enlarged to show detail)

Prevention and control of carpet beetles typically requires several steps.  Adults can typically be excluded from entering the home through basic repairs including replacing missing or damaged weather stripping and screens and sealing gaps and cracks around the foundation.  Maintaining sanitary conditions in which spilled foods are immediately cleaned as well as lint/pet hair or dead insect accumulations removed will aid in limiting breeding sites.  Storage of susceptible items in tightly sealed containers will limit access to the items by larvae.  This is especially important when the items are not commonly utilized as infestations may become severe or go unnoticed.  When an infestation is suspected it is important to locate and eliminate breeding sites.  A thorough cleaning of all areas may be necessary to ensure lint, pet hair and dead insects are removed, including moving furniture and items that are not moved on a regular basis.  Items that cannot be discarded will need to be treated by dry-cleaning, freezing for a minimum of 48 hours, heated to at least 120 degrees for several hours or treated with a residual insecticide treatment by a pest control professional.  Insecticidal control is important and should be used in coordination with cleanout of infested areas in order to obtain control.