Larder Beetles

Advice leaflet about Larder beetles

The Larder Beetle is one of a group of similar beetles in the genus Dermestes which are known collectively as Hide Beetles. It is found throughout Europe and is very widespread in the UK. All Dermestes species larvae feed on high protein diets, preferring material of animal origin. They occur naturally in birds' nests and many species have found intensive poultry houses to be an ideal substitute.

Significance

These are serious pests in industrial and domestic kitchens, particularly around food cupboards, cookers and refrigerators.

Their occurrence in kitchens is usually associated with poor hygiene which allows them to breed successfully on food scraps. The adult beetles fly readily, and are attracted at night to illuminated windows creating new infestations in the kitchen of flats, staff canteens and the upper floors of high-rise buildings.

Biology

The adult female beetle lays up to 200 eggs which hatch in about a week into small bristly larvae. In less than two months the fully fed larvae (after several skin moults) migrate from the food source and seek pupation sites nearby. They make pupation chambers by tunnelling into suitable adjacent materials, and have a particular attraction for wooden panelling and structural timbers. The total duration of the life cycle depends mainly on temperatures with a minimum of 17°C and an optimum of 24°C and takes from 8 to 12 weeks.

Control Measures

The first step in control is to trace the source of infestation. This is usually obvious although in domestic premises it may be obscure and found to be a dead animal that has passed unnoticed or an old bird's nest. In domestic situations, an integrated control programme of cleaning and spraying with a residual insecticide will control most infestation, although eradication of widespread infestations may take some time. If empty bird's nests have been an infestation source they should be removed.

Most residual insecticides will be effective if applied thoroughly to the structure, concentrating on the treatment of cracks and crevices with liquid or dust formulations.

Local Authority Service

The Public Health Department does not offer a treatment service for Larder beetles.

Private Pest Control companies do offer a treatment service for Larder beetles and you can find more information from your local telephone directory.