Varied carpet beetles probably can be found in most every house and building in the state. They are out of sight for most of the year while their larvae hide in drawers, closets, and assorted cracks and crevices. They could be thought of as the ultimate crack and crevice cleaners. However, this is not a widely held interpretation, especially if they are chewing on wool, silk, or cotton clothing.
Carpet beetle larvae resemble small, hairy, light tan to red-brown caterpillars (Figure 1). They avoid light and remain hidden in cracks and crevices, but occasionally one can be seen crawling slowly along while looking for a place to pupate. Wandering larvae should be relatively near their food source, which can be any of a variety of products. Food sources can include natural fibers, furs, hides, feathers, horns, bones, hair, processed cereals, dried foods, and flowers. They also may feed on accumulations of dead insects present in wall voids, fluorescent light fixtures, and attics.
Adults are approximately 1/16-inch-long beetles that have irregular patterns of many white, brown, and yellow splotches on their hard wing covers (Figure 2). They are active fliers that are attracted to light and often are found crawling on curtains or windows as they attempt to fly to flowers and feed on pollen.
Small numbers of adults or larvae are relatively common and can be cleaned up by hand and discarded. More thorough checking and cleaning are needed if large numbers are present. The vacuum cleaner is one of the best weapons to use against them. Rooms should be cleaned often enough to prevent the accumulation of pet hair, lint, crumbs, and other material on which these insect can feed. Close attention should be given to carpets (especially under furniture), rugs, draperies, upholstered furniture, and closets where natural fabrics and furs are stored. Also, examine registers and associated duct work, corners, cracks, baseboards and moldings, and other hard-to-reach areas.
Crack and crevice treatments along baseboards, using products labeled for indoor application against cockroaches and ants, can be made after the areas have been cleaned.
By Lee Townsend, Extension Entomologist