Flat grain beetle

Definition

A minute, flattened beetle in the family Laemophloeidae, specifically Cryptolestes pusillus, that infests stored grain and grain products. Adults and larvae feed on damaged kernels, germ, and cereal dust, exploiting compromised packaging or poor storage hygiene. The species is cosmopolitan in distribution due to human commerce and is a significant pest in granaries, flour mills, and household pantries.

Etymology

Named for its strongly flattened body profile adapted to hiding in narrow cracks and crevices among grain, and for its primary association with stored cereals.

Example

In Canadian grain elevators, flat grain beetle populations build up in residual grain accumulations and broken kernels, requiring fumigation or aeration to prevent spread to new shipments.

Synonyms

• Cryptolestes pusillus
• Lined flat bark beetle

Related Terms

• stored-product entomology
• Cryptolestes
• grain pest
• secondary pest
• Laemophloeidae
• Sawtoothed grain beetle
• Rusty grain beetle

Usage Notes

The common name 'flat grain beetle' applies specifically to Cryptolestes pusillus, though related Cryptolestes species (e.g., C. ferrugineus, the rusty grain beetle) are similar pests and sometimes confused in older literature. It is considered a secondary pest because it cannot attack intact grain kernels and requires existing damage or dockage. Contrast with primary grain pests such as Sitophilus weevils or Rhyzopertha dominica, which can bore into sound grain.