Commonly known as the carpet beetles, larder beetles and hide beetles. There are 850 species world wide, 50 European species and 40 British species.
The adults are covered with hair or scales, and the antennae are clubbed and can be drawn under the body with the legs. Most are scavengers, and some are pests.
The larvae are often called wooly bears. Dermestidae means "skin eater". Some of the pest species will eat both natural and synthetic fibres.
The adults often fall to the ground and feign death when disturbed. When the larvae are ready to pupate they will burrow into anything - even wood and lead.
Above is Anthrenus flaviceps, a furniture and carpet beetle. Adults are hardy enough to live outside.
Above is Attagenus pellio, the 2 spot carpet beetle, also known as the fur beetle. Adults are 3.5 - 6.0 mm long. It attacks skins, furs, textiles and entomological specimens.
Adults are dark brown to black with patches of white or yellowish hairs. Females lay 50 - 100 eggs on larval food, e.g. carpets, bird's nests. The larva are hairy with a tuft of long hairs on the last abdominal segment. They avoid light, and when disturbed play dead. The entire life cycle is anything from 6 months to 2 years.
Above is Dermestes lardarus, another member of the Dermestidae family. It is commonly known as the larder beetle or the bacon beetle.
It is fairly easy to recognise as the top half of the elytra (wing cases) are covered in a wide band of cream, yellow or tan coloured hairs with dark spots, and the adult antennae are strongly clubbed (see the drawing below.
Females can lay about 200 - 800 eggs in batches of 6 - 8 in their lifetime. The eggs are 2 mm long, and laid in crevices, or on or near food. The larva is covered in dark brown hairs, and favours dark places. They feed on ham, bacon other meats and cheese, in fact it will eat most animal substances; outdoors they can be found on carcases. The larva are usually found just before they pupate, as they leave their food and wander around to find a safe place. They often bore into wood, but can bore into lead and even tin. They will feign death if exposed suddenly to light. A fully grown larva is 10 - 15 mm long.
Once they have hatched into an adult they can be easy to find around windows as the try to escape outside to feed on their adult food of pollen. Adults are about 6 - 10 mm long.
The normal life cycle is 2 - 3 months, however this can be much longer as they can hibernate if the temperature falls. Nowadays they are less common in houses, and where they are found they will probably have been feeding on dead mice under floorboards, or dead birds in the chimney.
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