Confused Flour Beetle

Category:

Actual Size: 3.5 mm

Characteristics: Small, flattened; reddish-brown. Last three segments of antenna are almost equal in diameter.

Habits:

  • Economically important pest of flour and grain-based products.
  • In 5-8 months, female beetles lay 300-400 eggs in dry food products.
  • Adults can live three years or more.

Overview

A number of beetles infest flour and grain-based products and are known as flour beetles. Of these species, the confused flour beetle and the red flour beetles are the most economically important. The confused flour beetle occurs commonly in the northern part of the United States. This beetle is omnivorous, eating both plants and animals. Flour beetles are extremely important pests of flour, being the most commonly encountered pests in flour mills. They feed on grain dust and milled cereals, but are unable to attack sound and undamaged grain.

Confused Flour Beetle Habitat

The confused and red flour beetles live in the same environment and compete for resources.

Flour beetles can be found not only inside infested grain products, but in cracks and crevices where grain may have spilled. Flour beetles infest cereal, cake mix, cornmeal, crackers, and dry pet food, chocolate and nuts and seeds (such as bird seed). Both adults and small, off-white larvae will be found in an infested food item. The adult beetles often wander away from the infested material and will be found inside pantries and cupboards or anywhere in the home.

Confused Flour Beetle Behaviors, Threats or Dangers

Confused flour beetles do not bite or spread disease, however, they give off a displeasing odor, and their presence encourages mold growth in grain. They are attracted to grain with high moisture content and can cause a grey tint to the grain they are infesting. Common signs of an infestation are visual sightings of actual beetles crawling or flying throughout the home, seeing them in flour or cereal products, and “leaky packages.” Small bits of meal or grain spilling from a package, or small holes chewed through packaging, are signs that an infestation is present.

Confused Flour Beetle Prevention

Flour beetles feed and survive on the smallest bits of grain, so keeping storage areas clean and free of debris is crucial to prevent an infestation. Clean and vacuum pantry shelves regularly, paying attention to cracks and crevices. When shopping, look for leaky packages, inspect dry food items, and never purchase a broken or damaged package. Store dry food products in airtight containers or place in freezer. If an infestation is present, locate and discard all infested material.