Red flour beetle

Scientific name

Tribolium castaneum (Herbst)

Classification

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

Description

• 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.

Similar species

• Confused flour beetle (Tribolium confusum)
• Black flour beetle (Tribolium madens)
• American black flour beetle (Tribolium audax)
• Broadhorned flour beetle (Gnatocerus cornutus)
• Longheaded flour beetle (Latheticus oryzae)

Commodities affected

• 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

Damage

• 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

• Control grain insect pests

Geographic range

• Is found across Canada
• Survives Canadian winters in heated and protected places
• Is distributed worldwide and is more common in warmer climates

Where found

• 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

Life history

• Each female lays 400 to 500 eggs.
• Breeding takes place in a temperature range of 22^oC to 40^oC.
• Optimum development occurs in the range of 32^oC to 35^oC.
• Red flour beetle has one of the highest rates of population growth for stored-product insects.

Video

• Video of Red flour beetle