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Flour Beetles Stored Products Pests

The confused flour beetle (Tribolium confusum), a type of darkling beetle known as a flour beetle, is a common pest insect known for attacking and infesting stored flour and grain. They are one of the most common and most destructive insect pests for grain and other food products stored in silos, warehouses, grocery stores, and homes.

Appearance

The confused flour beetle is very similar in appearance and habit to the red flour beetle, Tribolium castaneum and the destructive flour beetle, Tribolium destructor. Both the confused flour beetle and red flour beetle are small, about 1/8 to 1/4 inch in length, and reddish-brown in color. The primary distinguishing physical difference is the shape of their antennae: the confused flour beetle's antennae increase gradually in size and have four clubs, while the red flour beetle's antennae have only three.

Additionally, red flour beetles have been known to fly short distances, while confused flour beetles do not. Tribolium destructor is much darker than either and less common.

The "confused" in the beetle's name is due to being confused with the red flour beetle, and not because of its walking pattern.

Habits:

While confused (and red) flour beetles cannot feed on whole, undamaged grain, they are often found in large numbers in infested grains, feeding on broken grain, grain dust, and other household food items such as flour, rice, dried fruit, nuts, and beans. Both types of beetles are often found not only in infested grains, but in crevices in pantries and cabinet, as well. Damage to food is caused somewhat by the beetles' feeding, but also by their dead bodies, fecal pellets, and foul-smelling secretions. In addition to creating a foul odor, the beetles' presence encourages the growth of mold.

Prevention & Control:

  1. Remove dry pantry foods and bulk foods from original containers and store them instead in tight-fitting containers. (Pasta, cereal, flour- anything that comes in a paper or cardboard box).
  2. Clean pantry shelves regularly, as this will help to remove small bits of food that Red flour beetles need to survive.
  3. Never purchase a broken or damaged package. The chance of these being infested is greater than for perfectly sealed ones.
  4. Do not mix old and new lots of foodstuffs. If the old material is infested, the Red flour beetles will quickly invade the new.
  5. Clean old containers before filling them with fresh food. They may be contaminated and cause a new infestation.
  6. Keep storage units dry. This is important because moisture favors the development of Red flour beetles; dryness discourages them.