Commonly known as the carpet beetles, larder beetles and hide beetles. There are over 1000 species world wide, 50 European species and 40 British species. About half the species found in Britain can only be found in artificial habitats created by man, where they feed on wool, hide, dried meat, etc. Only 11 species are truly native to Britain. British species range in size from 1 - 12 mm.
The adults are covered with hair or scales (see the photographs below), and the antennae are clubbed and can be drawn under the body with the legs. Most are scavengers, and some are pests. Some species are completely reliant on man and cannot be found in the wild.
The larvae are often called wooly bears and are hairy and have well-developed legs. Dermestidae means "skin eater". Most of the larvae feed on animal material, but some can live on vegetable material. However many that are found in stored grain products, for example, are actually feeding off the dead insects that feed on the grain. Some of the pest species will eat both natural and synthetic fibres. When the larvae are ready to pupate they will burrow into anything - even wood and lead.
The adults often fall to the ground and feign death when disturbed. Many adults do not feed, or may feed on pollen and drink nectar. Often the first sign of an infestation is during the warmer months, finding an adult beetle or beetles on windowsills trying to get out as they are attracted to light. This adult will probably have already mated, and if a female will have laid her eggs in a suitable place for them to hatch and start eating. Simply washing rugs and wiping floors etc. is enough to get rid of a small infestation as the eggs cannot stand high humidity.
Above is Anthrenus flaviceps, a furniture and carpet beetle. Adults are hardy enough to live outside. Adults are 2.0 - 3.5 mm long. Originally this was an oriental species, but is now found in warmer areas world wide. The life cycle takes from three months to two years depending on conditions. It is possible for the larva to survive sub-zero temperatures.
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 they 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.
the the main beetle page for beetle fast facts, diagram of adult beetle body, list of beetles featured