Furniture Carpet Beetle and Larva

Wool eating caterpilar
Location: New York City
August 5, 2011 6:13 pm
Have these wool eaating caterpilars in my closets. What are they? Never seen any moths but occasionally see a small ladybug sized beetle which I suspect is the same animal.
Just to let you know that the caterpillar is about 1/8 inch long.
Signature: NYC

Dear NYC,
This is most certainly a Carpet Beetle and a Carpet Beetle Larva, and it very closely resembles a Varied Carpet Beetle, Anthrenus verbasci , however, the larva is too dark to be that species.  It is highly unlikely that you would have the larvae of one species in your closet and the adult of another species, so we continued to research.  We learned upon reading about the Varied Carpet Beetle on BugGuide, that it looks very similar to the Furniture Carpet Beetle, Anthrenus flavipes, but alas, BugGuide has no photos of the Furniture Carpet Beetle.  We did find a photograph on IPM images, that is credited to Clemson University – USDA Cooperative Extension Slide Series, that shows the Furniture Carpet Beetle and its Larva, and we believe they match your individuals. Carpet Beetle Larvae do feed upon wool, though the adults feed on pollen.  We did locate an awesome webpage entitled Urban Entomologywritten by Walter Ebeling that is on the UC Riverside Entomology website.  Here is what it says about Carpet Beetles:  “Four species of carpet beetles comprise not only the most important group of fabric pests, but also the group that is most difficult to control. The adults feed largely on pollen and nectar, and may enter homes in spring and early summer. All damage (figure 200) is done by the larvae, which develop in dark, undisturbed locations. Unlike clothes moth larvae, they spin no webbing, but their hairy cast skins and their sandlike pellets (shown in the figure; often the color of the fabric eaten) are evidences of infestation. The cast skins look much like live larvae, and may give the casual observer the impression that there is a greater infestation than is actually present. Pupation takes place in the last larval skin, and the adult may remain in the partially shed pupal skin for as long as 3 weeks. Evidence of a carpet beetle infestation may be the presence of the small, adult beetles flying to windows or larvae wandering from room to room. The adults resemble lady beetles in shape.  The source of a carpet beetle infestation is sometimes difficult to find. For example, one pest control operator treated an office building 3 times, each time failing to find the source of the beetles seen by the occupants. On the fourth attempt, he traced the beetles to a telephone cable in the wall, where the insects were discovered to be feeding on the insulation.”  The Urban Entomology page also states this, which supports our identification:  “Mature larvae are darker than those of the varied carpet beetle, and are able to run swiftly.”

Wow, that was quick! Thanks!