Rust-red Flour Beetle
IdentificationThe Rust-red flour beetle is red-brown in color. 3.0 - 4.0 5mm in length. The antenna of the rust-red flour beetle is distinctly club-like, with a three segmented club and it has grooved wing covers. The Rust-red flour beetle has well developed wings and has been observed to fly. The larvae are a light honey color and about 6 mm long. The head and a distinctive forked process at the tip of the abdomen are slightly darkened.
DescriptionIs a very common commercial pest infesting a variety of grain and food materials. The rust-red flour beetle is frequently found in stored products in Australia. When agitated or crowded, they may secrete chemicals called quinones. These chemicals can cause the infested feed to turn pink and have a pungent odor. 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. In general, fungi may play a significant role in the nutrition of rust-red flour beetles. The female lays approximately 400 - 500 eggs, with peak oviposition occurring during the first week. Adults may live longer than 3 years, and females may lay eggs for more than a year. Eggs are deposited directly in flour, other food material, or attached to the surface of the container. They are white or colorless 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 favorable food. 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 and >70% relative humidity.