Spider beetles get their name from their striking resemblance to spiders — their round, shiny abdomens and long legs give them an arachnid-like appearance that often startles homeowners who find them in the pantry. Several species are found in Arizona, including the American spider beetle (Mezium americanum) and the smooth spider beetle (Gibbium aequinoctiale). Despite their spider-like appearance, they are beetles (order Coleoptera) and are completely harmless to humans. Spider beetles infest a wide range of dried organic materials: flour, cereals, dried fruit, spices, dried meat, feathers, wool, and even old books and museum specimens.

Controlling spider beetles in Arizona requires a thorough inspection of not just the pantry but also storage areas throughout the home. Spider beetles are scavengers that feed on a wide variety of organic materials, so the infestation source may not be obvious — check old bird nests in the attic, rodent droppings, dried flower arrangements, old wool clothing, and forgotten food items in the back of cabinets. Discard all infested materials and vacuum thoroughly. Store all food products in airtight containers. Because spider beetles are nocturnal and slow-moving, they are often found wandering on pantry shelves at night.

Spider beetles are year-round pests in Arizona and are most commonly found in older homes with accumulated organic debris in attics, wall voids, and storage areas. If you find spider beetles in multiple locations throughout your home, a professional inspection is recommended to locate all harborage sites. Pest Control Bros LLC provides stored-product pest inspections and treatment throughout Maricopa, Chandler, Mesa, Tempe, Gilbert, and Casa Grande. Call (520) 424-5244 for a free inspection.