Rhyzopertha dominica (lesser grain borer).
Abstract Females of R. dominica lay between 200 and 500 eggs in their lifetime. The eggs are laid loose in grain. The lowest temperature at which R. dominica can complete development is 20°C; at this temperature, the development from egg to adult takes 90 days. The fastest rate of development occurs at 34°C; at this temperature the egg takes 2 days, the larvae 17 days, and the pupae 3 days to complete development. R. dominica is unable to complete development between 38 and 40°C. Adults live for 4-8 months. Under optimal conditions of 34°C and 14% grain moisture content, there is a 20-fold increase in the population of R. dominica after 4 weeks. It can successfully infest grain at 9% moisture content, but has higher fecundity, a faster rate of development, and lower mortality on grain of a higher moisture content. Adult males produce an aggregation pheromone in the frass that attracts both male and female adults. Adults are good flyers, and can be trapped in pheromone-baited flight traps placed several kilometres from grain stores. Adults can bore into intact kernels. The larvae of R. dominica are mobile.