Whitemarked spider beetle

Classification

Secondary pest; Grain feeder and scavenger
Order: Coleoptera
Family: Anobiidae
Acronym: PTI

Description

• Adults are morphologically similar to other spider beetle species, notably the hairy spider beetle (Ptinus villiger).
• Adults can be separated from other spider beetles by examination of the setae on the elytra. On P. fur the setae on the elytra are equal in length; this is not the case in P. villiger.
• Larvae are grub like and white in colour.

Similar species

• Hairy spider beetle (Ptinus villiger)
• Other spider beetles

Commodities affected

• Affect flour, corn meal, bran, seeds, grain, pepper, cocoa, sugar
• Is a serious pest of zoological collections
• Is reported to feed on grain dust in terminal elevators

Signs of infestation

• Presence of webbed, granular material
• Irregular damage (chewed holes) to endosperm

Damage

• Damage results from accumulation of silk and granular material

How to control

• Control grain insect pests

Geographic range

• Is found worldwide and across Canada
• Is most abundant in British Columbia

Where found

• Feeds on a variety of dried and decaying animal and vegetable material
• Requires high humidity to effectively reproduce
• Is found mainly in warehouses and dwellings
• Is less frequently found in museums, granaries and grain elevators

Life history

• Females lay eggs in cracks and crevices around the food supply.
• Larvae may be somewhat gregarious and form feeding clusters of 3 to 4 individuals amongst several kernels glued together.
• Larvae secrete a silky substance to form a puparia.