Grain Beetles

Oryzaephilus spp.; Tribolium spp.

Grain beetle

Sawtoothed grain beetle (Kansas Deptartment of Agriculture Archive,


Left: Red flour beetle adults (Emilie Bess, USDA APHIS PPQ, Right: Red flour beetle larva (Frank Peairs, Colorado State University,

In wheat

Red flour beetle in wheat (Clemson University,


  • 1/8 inch long; brown to red
  • use hand lens to identify
  • sawtoothed grain beetle has spines on side of body behind the head
  • red flour beetles have clubbed antennae and eyes split above and below the head
  • other small beetles in grain also exist; consider collecting beetles for identification by USU Extension

Nesting Habits

  • lay eggs on stored food products, especially of high moisture content
  • prefer damaged food rather than intact grains, kernels, etc.


  • highly varied
  • grain products, cereals, breads, peas, beans, dried meats, macaroni, nuts, dried fruits, spices, chocolate, drugs, tobacco, herbarium, insect and museum specimens


  • infest food, rendering it inedible

IPM Recommendations

  • Improve sanitation procedures in affected areas.
  • Inspect all incoming food items for pests.
  • Store all susceptible food items in pest-proof containers.
  • Dispose of infested food items.
  • Keep moisture low in food storage areas by improving ventilation.
  • Keep food in regular rotation.

Additional Resources

IPM for Fabric and Pantry Pests: Integrated Pest Management in Sensitive Environments (University of Nebraska-Lincoln Extension)