Rust-red Flour Beetle (Tribolium castaneum)

Rust-red flour beetles can be found infesting a variety of grain and food materials. They have been reported in grain, flour, and other cereal products, beans, cacao, cottonseed, shelled nuts, dried fruit, dried vegetables, drugs, spices, chocolate, dried milk and animal hides. They cannot feed on whole grain, but can feed on broken kernels that are usually present.

Identification:
Red-brown in colour and about 3 - 4 mm in length. The larvae are a light honey colour and about 6 mm long. The rust-red flour beetle and the confused flour beetle are often grouped together due to the similarity in their appearance, biology, and behaviour.

Biology:
Eggs are deposited directly in flour, other food material, or attached to the surface of the container. They are white or colourless and covered by a sticky material to which flour can adhere. Eggs hatch in 3 - 5 days at 32 - 35°C. Larvae burrow into kernels of grain but may leave their burrows in search of a more favourable food. There are 5 - 11 larval instars, the variation a result of environment, food, temperature, humidity, or the individual insect. Larvae are fairly active but generally hide within the food, away from light. Development time from egg to adult varies with conditions, however the average is 26 days at 32 - 35°C.

Control:
Infestations in domestic or food storage situations can usually be traced back to a cereal source. Since these beetles can infest so many types of grain products, inspect thoroughly. There may be several infested products, discard any food that is infested. Infested areas should be thoroughly vacuumed paying particular attention to cracks and crevices, contents of the vacuum cleaner should be disposed of in an outside bin. Store new food products in sealed glass or plastic containers. After cleaning, treat the infested areas using a residual insecticide labeled for crawling insect to ensure that all adult beetles and larvae have been killed.

Products to control Rust-red Flour Beetle: