Effectiveness of protein‐rich pea flour for the control of stored‐product beetles

Abstract

AbstractProtein‐rich pea flour is toxic to many stored‐product insects. We investigated several factors that may affect the efficacy of protein‐rich pea flour: insect species, insect population densities, grain species, temperature, and moisture. Adult Sitophilus oryzae (L.) (Coleoptera: Curculionidae) was more susceptible to protein‐rich pea flour than Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae). Protein‐rich pea flour did not increase the mortality of adult Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). However, it reduced the number of offspring of all three species. The toxicity of protein‐rich pea flour was not reduced after 9 months when stored at −15 °C, or at room temperature as flour or mixed with grain. Its toxicity in wheat increased with higher temperature and at lower grain moisture contents. Protein‐rich pea flour was more toxic in wheat and barley than in maize. This difference among grain species was not due to the kernel size of the grain, as ground wheat or maize with the same particle size still had different LD50s.