Red flour beetle
Tribolium castaneum (Herbst)
Primary pest; Grain feeder
- Adults are a small reddish brown beetle and are about 4 mm long.
- Adults are easily confused with other Tribolium species.
- Larvae are whitish with brown bands.
- Larvae reach a length of 8 mm prior to pupation.
- Stored grains, oilseeds
- Starchy materials, beans, peas, spices, dried plant roots, fruit, yeast, chocolate
- Consumes dead insects, herbarium specimens
- Prefers damaged grain but will attack intact wheat kernels, feeding first on the germ and then the endosperm
Signs of infestation
- Heated grain
- Pinkish coloration to food products at very high population densities
- Is a generalist feeder and 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
- Is typically found in grain that has become heated
How to control
- Is found across Canada
- Survives Canadian winters in heated and protected places
- Is distributed worldwide and is more common in warmer climates
- Is found in grain bins, elevators, vessels, railcars, mills
- Is occasionally found in retail stores and warehouses
- May infest packaged food
- Is capable of flight in warm weather
- Is more common in grain stores than the confused flour beetle
- Is one of the most common grain feeding insects found in grain stored on Canadian farms
- Each female lays 400 to 500 eggs.
- Breeding takes place in a temperature range of 22oC to 40oC.
- Optimum development occurs in the range of 32oC to 35oC.
- Red flour beetle has one of the highest rates of population growth for stored-product insects.
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Video of Red flour beetle
Several adult red flour beetles move across grains of wheat. The grains show signs of damage caused by the beetles.
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