Species: Varied carpet beetle (Anthrenus verbasci); Furniture carpet beetle (Anthrenus flavipes); Black carpet beetle (Attagenus unicolor)
What to look for
- Adult size and outline. Kentucky gives adult carpet beetles as 1/16 to 1/8 inch (1.6 to 3.2 mm) and oval. Maryland gives the varied carpet beetle adult as 2 to 3 mm (about 0.08 to 0.12 inch).
- Adult pattern. Colors run from black to mottled patterns of white, brown, yellow and orange. Maryland describes the varied carpet beetle as splotched white and yellow, looking like a gray calico, and the black carpet beetle as solid dark brown or dull black and a longer oval. UC IPM notes those scales wear off in older adults, so old beetles look solid brown or black.
- The larva, which is what you usually find. 1/8 to 1/4 inch (3.2 to 6.4 mm), tan to brownish, slow moving and densely covered with hairs or bristles.
- Larva shape tells the species apart. The varied carpet beetle larva is tear-drop shaped with rows of light brown hairs, while the black carpet beetle larva is 3 to 7 mm long, carrot shaped, golden brown haired and carries a tail of long hairs at the rear.
- Shed skins and pellets. Kentucky and Maryland both note that larvae leave molted skins behind, and Maryland says light-colored skins in the material signal a heavy infestation. UC IPM adds fecal pellets about the size of a grain of salt.
- Where it was found. Kentucky says adults often appear on windowsills in spring, while larvae prefer rug edges and undersides, fabric folds such as cuffs and collars, and lint under baseboards and inside floor vents.
Where and when
Kentucky extension puts adults on windowsills in springtime and the larvae in dark, undisturbed places: the edges and undersides of rugs, seams and folds of stored woolens, closets, chests, and accumulations of lint and pet hair along baseboards, air vents and ducts. It adds that infestations often stem from bird nests, animal carcasses or piles of dead insects in attics and chimneys.
Does it matter?
Kentucky extension says the larvae digest keratin, so they feed on wool, felt, fur, silk, feathers and leather, and leave threadbare spots and irregular holes; cotton and synthetics are rarely attacked unless blended with wool or heavily soiled. Maryland says the adults do not damage fabrics at all and feed on pollen or not at all. Kentucky's remedy is cleaning and sealed storage.
Related guides
- Silverfish: A silverfish is a wingless, flat, teardrop-shaped insect covered in silvery scales, with long thread-like antennae and three tail-like appendages at the rear.
- Weevils and flour beetles: The snout tells you which group you have.
- Bugs that look like bed bugs: Size sorts most of it.