Variegated Carpet Beetle
Variegated Carpet Beetle
The variegated carpet beetle (Anthrenus varbasci) is commonplace. On emergence as adults they seek light and fly freely to colourful flowers where they feed on pollen and nectar on plants during the summer months. After mating the females enter houses and lay their eggs in bird’s nests getting into roof voids, pipe lagging and airing cupboards.Henceforth into rooms where stored woollens and carpet edges by skirting boards are particularly exposed to attack. The larvae feed on feathers or wool soiled with faeces and dead fledglings. They continue to feed in warm dry conditions where they may wander further towards carpet fabrics.
Between 20 to 100 eggs are laid by the female during spring and early summer on woollen carpets, clothing e.g. furs or feathers, museum specimens or anything of an animal origin. Damage is caused by the larvae where by comparison the adults are harmless. Hatching in 10 – 30 days depending on room temperature ranging from 18C°-30C°. Larvae can resist starvation for up to 10 months. They are 4 to 5mm in length, hairy and brown in colour with golden hairs on each side of the abdomen, often referred to as “woolly bears”. The larvae tend to roll up into golden balls when disturbed. Adults appear during April – June and their resulting larvae hibernate during the following winter, pupating during the latter part of February and March. They can moult five times and take several months to develop.
Infestations of carpet beetles usually originate in the bird’s nests of house sparrows, house martinsor starlings. They can be found by window ledges having failed to escape via an open window. The first rule of control is to remove bird’s nests from eaves or similar locations. Dead birds or rodents should be removed from under
floorboards. Old carpets in loft spaces should be disregarded and destroyed as they act as reservoirs of infestations. Carpets and clothing should be treated with a moth-proofer spray particularly under skirtings or carpet edges. Vacuum cleaning should be focused on cracks and crevices with a nozzle attachment removing debris and larvae. Similarly, professional residual insecticide needs to focus on cracks and crevices. Desiccant dust formulations are effective also but leave for sufficient time before cleaning and vacuuming away.
Perseverance and patience must be exercised with variegated beetle as immediate results are seldom achieved.
Mervyn WalshBA(Hons), HDip.EnvMgt, MRSPH
Field Conservation Biologist