Effect of temperature on biological control of confused flour beetle, Tribolium confusum (Coleoptera: Tenebrionidae)

Stored product pests account for as much as 10% loss of food worldwide. Insects, such as the confused flour beetle, Tribolium confusum, are a major pests of small grain in storage bins and grain elevators in Montana. Cold winters and dry summers have traditionally helped to control the presence of T. confusum in storage bins. However, with increasingly mild winters this pest has become harder to manage. The chemical insecticide aluminum phosphide is a highly effective treatment for stored grain pests due to its high toxicity to animals and its ability to leave the grain within several days after treatment. However the high toxicity to mammals is a concern for anyone working around this chemical and requires measures that limit exposure that can be costly for grain elevators and millers. Newly approved biological controls exhibit appreciable levels of control without the high toxicity of aluminum phosphide. In this study, we tested the short term effectiveness of the biological control agents under different temperature regimes. We tested the commercially available compounds Entrust® (extracts of Saccharopolyspora spinosa) and BotaniGuard (Beauvaria bassiana GHA) for their effectiveness against the confused flour beetle. We find that temperature is an important determinant in the effectiveness of these biocontrol agents.