Friday, May 02, 2008
Carpet Beetles Rain on Me
Today I was called to the garage to investigate the strange occurrence of tiny beetles falling from *somewhere* onto the garage floor. When I arrived on the scene there were scores of tiny (~2mm) round variegated brown beetles, some crawling, on the cool concrete between the shelves with the auto cleaning supplies and short-handle tools (left side) and the nuts and bolts (right side). I picked up a couple of them for closer examination but need magnification for my old eyes to see these are Anthrenus verbasci, the varied carpet beetle. I have been seeing lots and lots of these guys working the flowers for pollen and nectar, which is what the adults feed on. The larvae feed on a wide range of dead animal matter, including woolen carpets, clothing and furs which is the source of their reputation as a household pest and their name. The name is a bit of a misnomer, since the beetles (adults) do not feed on carpets but seek them out as a place to lay their eggs.
OK. It was obvious these carpet beetles were emerging after pupating somewhere in the garage since they would not normally seek out that habitat (dark, no flowers to feed on). Looking up, I found the likely source in a large messy and carcass-littered spider nest covering the skylight. Dead insect matter in wasp-, spider- or bee nests are a natural egg-laying site for these beetles (when they can't find fine carpets or furs). Some of the beetles had gotten caught in the web. I guess one way to reduce the numbers of carpet beetles might be to vigilantly clean up spider webs around the place; I was a bit shocked at how slovenly this particular web was, and at how many beetles it was producing. Anyway, I've never seen any larvae inside our house, which maybe says a lot for my housekeeping skills, or maybe speaks more for our lack of woolen carpets, furs and leather-bound books. If we had those I might be more concerned about the carpet beetle population; or maybe I secretly hope the larvae will attack our leather upholstered couch that has disappointed us with its gross lack of comfortableness since day one.