Confused flour beetle

Tribolium confusum (Jaquelin du Val)


Primary pest (mills); grain feeder
Order: Coleoptera
Family: Tenebrionidae
Acronym: TCO


  • Adult is a small reddish-brown beetle, about 4 mm long.
  • Adult is easily confused with other Tribolium species.
  • Larvae are whitish with brown bands.
  • Larvae reach a length of 8 mm prior to pupation.


Similar species

Commodities affected

  • All type of grains, cereal products, flour, animal feed, sunflower, millet
  • Starchy materials, beans, peas, spices, dried plant roots, dried, fruit, yeast, dried chocolate
  • Dead insects, herbarium specimens

Signs of infestation

  • Heated grain
  • Pungent odour


  • Is a generalist feeder, so damage is not readily attributable to this pest
  • Releases a noxious secretion, when disturbed, resulting in a pungent odor in the infested commodity, rendering milled products unfit for consumption
  • May cause food to acquire a pinkish tinge when a large number of insects are present

How to control

Geographic range

  • Is found around the world and across Canada
  • Survives Canadian winters in heated and protected places
  • Is more common in warmer climates

Where found

  • Is mainly found in flour and feed mills
  • May also be found in warehouses, granaries, bakeries, homes and stores
  • May infest packaged food
  • Infests whole grain, but only feeds on dust and broken kernels
  • Is typically found in grain that has become heated

Life history

  • Each female lays 200 to 700 eggs loosely in food.
  • Breeding takes place in a temperature range of 20oC to 37oC.
  • Optimum development occurs in the range of 32oC to 35oC.
  • Confused flour beetle has one of the highest rates of population growth for stored-product insects.
  • The beetle is able to breed under cooler conditions than the red flour beetle.

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