Common Name Scientific Name
Hairy Spider Beetle Ptinus villiger (Reitter)
Whitemarked Spider Beetle Ptinus fur (Linnaeus)
Brown Spider Beetle Ptinus clavipes Panzer
American Spider Beetle Mezium americanum (Laporte)
Australian Spider Beetle Ptinus ocellus Brown
Spider beetles are general scavengers. They feed on a variety of items, such as cereals, seeds, flour, meat, dried fruits and vegetables, fish food, dead insects, rodent droppings, old wood, cayenne pepper, roots, cocoa, sugar, drugs and spices. Common sites of infestation in the house include wall voids and drop ceilings. Spider beetles are primarily warehouse pests, attacking various seeds and certain whole grains, such as wheat, barley, rye, and flax. Also, serious infestations have been found in flour and feeds, such as bran shorts and meal preparations. Larvae cause a typical "scarring" of the wood in buildings in the formation of pupal cells prior to pupation. Spider beetles sometimes become prominent cereal pests in Canada and the northern United States. Some have been found quite active even during freezing weather. They do not bite or sting humans or pets, spread diseases, or feed on or damage the house or furniture.