American black flour beetle
Tribolium audax (Halstead)


Secondary pest: Grain feeder
Order: Coleoptera
Family: Tenebrionidae
Acronym: TAU


  • Adults are 2.8 to 4.5 mm long.
  • Adults are most similar in appearance to Tribolium madens (black flour beetle).
  • Eyes are relatively round (the black flour beetle’s eye is oval).
  • Larvae are cylindrical and dark brown in colour.

Similar species

Commodities affected

  • Cereal grains, flour, meal, seeds and cereal products

Signs of infestation

  • Disagreeable odour in the commodity is an early indication


  • Damage is not distinctive

How to control

Geographic range

  • Throughout Canada

Where found

  • Is occasionally found in empty granaries in western Canada
  • Does not normally infest stored grain

Life history

  • Adults live on average 2 to3 months.
  • Adult females lay up to 1000 eggs loosely among the food source.


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Did you know?

The American black flour beetle is found more often than the European black flour beetle.