Drugstore beetle (Stegobium paniceum)

Pest type: Primary pest, secondary pest

Distribution: World, tolerant of temperate conditions

Identification: Adults are 3-4 mm, brown, globular, with the last three segments of antennae forming a loose club, and the elytra having fine longitudinal ridges and fine hairs. Drugstore beetles can be recognized by the neck shield like a cowl that covers the head and the elytra that make fine longitudinal striations. At first they look like woodworm beetles, because they belong to the same family. Larvae: scarabeiform, with fully-developed legs.

Similar species: Lasioderma.

Life cycle: The optimal development condition is in 40 days at 30 ºC, 60-90% r.h. The development from egg to beetle at 18 ºC is 7 months. The higher the temperature, the faster the development will be. The female beetle lays about 60 eggs. Eggs are laid in crevices in the commodity. After 28 days the larvae hatch from the eggs, which pupate in a cocoon made of food particles and saliva. Larvae are internal feeders, immobile when mature. Adults are active, short-lived, and do not feed on commodities and fly.

Commodities infested: Dried material of animal and vegetable origin, especially nuts, herbs and spices, seeds, grain and grain products. If dry food products are affected, this can be detected through the round holes in the product. These are the openings for the adult beetles to fly away, and in flour products this can be detected by the presence of cocoons located on the walls and on the bottom of the packing material. They pierce to fly out by boring through plastic and paper.

Preventive measures are to keep the storage places cool and dry and clean empty spaces.

Treatment: Controlled Atmosphere for infestation in product
Treatment: Heat Treatment for infestation in buildings