Skin Beetles-Dermestidae

Anyone who mounts a collection of insects or animals will sooner or later confront the tiny beetles of the family Dermestidae. They arrive unannounced, and for a while they are unseen guests. After a time, however, you will know that they have moved in. A sprinkling of fine powder under a specimen is usually the first sign. Although the specimen appears unchanged, by this time it is nothing but a hollow shell. Before long there will be nothing left but the mounting pin.

The Dermestidae are voracious scavengers and will feed on almost any dry, processed, or putrefied material of animal origin. Their catholic tastes have caused them to be both valued for their role in removing decaying organic material, and feared for the destruction they cause.

Dermestes lardarius, for example, commonly called the larder beetle usually strikes in the home, devouring such foodstuffs as dried meats, sausages, dried fish, and cheese. Some species attack bales of skins awaiting tanning, silkworm cocoons, and "wool carpeting. Some are found in grain silos and in the holds of ships. The Dermestidae also are found in the nests of insects, birds, and rodents where they feed on excrement. Some of these hungry beetles have been known to invade museums and attack mummies in their cases.

The Dermestidae are small, compact beetles with wing covers extending over the entire abdomen. The head is recessed into the prothorax, and the legs and antennae can be folded into special grooves. They are usually quite handsome insect, with brightly colored hairs and scales covering their dark bodies. The larvae are distinguished by tufts of long bristles that extend from various parts of the body.