Prostephanus truncatus

Prostephanus truncatus is commonly referred to as "larger grain borer" with reference to the related Rhyzopertha dominica, which is relatively smaller in length, hence is referred to as the "lesser grain borer". P. truncatus is about 6 mm (0.24 in) long as compared to 3 mm (0.12 in) long in Rh. dominica. At optimum conditions of 80% relative humidity and 32 °C (90 °F), and available food, P. truncatus completes its lifecycle within 27 days. It is a serious pest of dried grains, especially maize and dried cassava in West Africa. This beetle is believed to have been introduced into West Africa through food aid from America. It reached Africa through Tanzania in the early 1970s.