The adult carpet beetle has attractive black wing casing mottled with patches of white and pale yellow, is up to 4mm long and is found outdoors from spring to early summer feeding on pollen and nectar before moving indoors to lay its eggs.
The larvae require a protein diet and are, therefore, to be found in birds’ nests, animal furs and skins and carpets where they feed voraciously. The larvae are approximately 5mm in length and are commonly known as woolly bears due to their characteristic covering of hairs.
The carpet beetle is a major textile pest of the home where central heating provides a welcome uniform heating and fitted carpets provide harbourage for undisturbed breeding.
An adult female will produce up to one hundred creamy white eggs and deposit them in cracks and crevices. Within four weeks the eggs hatch and the emergent woolly bears embark on a continuous feeding binge and moult several times before pupating; the length of the larval life is normally sixty-seventy days but this may increase or decrease depending on temperature, humidity and diet. They certainly have a capacity to hibernate in cold conditions and to remerge in spring. The adult lives for up six weeks during which time it will fly off in search of pollen and nectar and for egg laying sites.
Carpet beetles neither carry germs nor do they spread disease hence their presence does not constitute a risk to health. However, the activities of the woolly bears will cause damage and indeed ruin carpets, animal furs and leathers.
Carpet beetles have a capacity to wander and hence infestations, whilst manifesting themselves initially in one room, may also exist in others and hence vigilance is required.
It is important to first trace the source of the infestation. Check the roofspace for old birds’ nests and wool based lagging or other materials, examine the cracks between floorboards around the edges of rooms and under skirting boards for accumulations of debris and check sheepskin rugs and all animal fur/skin clothing.
Infested nests and inexpensive materials should be removed and burned and the areas from which they have been removed thoroughly vacuumed using a nozzle head and paying particular attention to cracks and crevices.
The above should be complemented by treating using a residual insecticide to ensure that all larvae have been killed. The powder containing BENDIOCARB and available in a puffer pack, can generally be used on infected carpets although a small area of the carpet should be tested before a full treatment is carried out. As for leather clothing, etc, specialist advice should be sought from reputable traders in such products.
Not all insecticides are safe for use indoors, particularly where food is present or on certain materials/surfaces. To protect yourself and others and to minimise damage to the environment ALWAYS READ AND FOLLOW THE APPLICATION AND USE INSTRUCTIONS PRINTED ON THE CONTAINER.
Although the adults have a distinct white spot on each wing casing and the larvae are different in appearance to woolly bears, the life cycle of the fur beetle is similar to that of the carpet beetle and certainly the larvae cause similar damage to fabrics, animal skins and fur coats.
Bath & North East Somerset Council’s advice on control measures, safety, etc, is therefore as for carpet beetles.