Size
1/10”-1/8”
Color
Reddish brown
Description
The Foreign Grain Beetle feeds on fungus and is a most notable nuisance when it invades commercial and residential buildings. The female Foreign Grain Beetle lays her eggs on fungus growing on wood that became wet during construction. Larvae feed on the fungus and do not damage the wood or building structure.
The fungus usually dies in a year or two when the wood naturally dries and adult beetles may come ‘out of the woodwork’ in search of new food sources. If the building is not new, the presence of Foreign Grain Beetles may indicate a plumbing leak or other moisture related problem inside the building.
Foreign Grain Beetles can also be found in flour and cereal mills feeding on fungus or molds on discarded food. If Foreign Grain beetles are found in stored food then mold or fungus is present in the food.
Control Advice
If construction is new, vacuum beetles to prevent them from moving to another location. Inspect older buildings for water leaks and replace moldy wood.
Active Seasons
The Foreign Grain Beetle is most active in late summer and early fall.
Photo courtesy of MAF Plant Health & Environment Laboratory