Broadhorned flour beetle

Gnatocerus cornutus (F.)


Secondary pest; Grain feeder
Order: Coleoptera
Family: Tenebrionidae
Acronym: GCO


  • Adult males and females differ in appearance.
  • Both genders are reddish brown and shiny, but females lack the horns found on males.


Similar species

Commodities affected

  • Flour, meal, dried cereal and animal products
  • Rice, maize, oil containing seeds, peanuts and cocoa beans

Signs of infestation

  • Disagreeable odour in the commodity
  • Large numbers indicates of broadhorned flour beetles indicates old stores of poor quality


  • Prefers to feed on the protein-rich outer parts and starch of cereal grain
  • Does not cause distinctive damage

How to control

Geographic range

  • Is distributed worldwide
  • Has been found across Canada

Where found

  • Prefers flour and meal
  • Is a minor pest of cereal and animal products
  • Is reported mainly in flour mills and warehouses
  • Is only able to survive winters in heated buildings

Life history

  • In Canada, females lay eggs amongst the food.
  • Larvae hatch and move freely among the food, feeding.
  • Adults are relatively long lived (7 to 12 months), feed and are able to fly.
  • This species is partially predatory, feeding on living and dead insects, as well as other animal protein sources when available.

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