Prostephanus truncatus

Prostephanus truncatus is commonly referred to as larger grain borer (LGB) with reference to the related Rhyzopertha dominica, which is relatively smaller, and 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 R. 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. LGB attacks maize right from the field and continues in the store. It also feeds on wood, plastics, storage bags and cassava. LGB bores into the grain, and feeds, leaving an empty shell, while the weevil only feeds on the heart of the grain. LGB also lives in the granary (unmudded nkhokwe ), especially in old maize granaries, and is ready to attack as soon as maize is placed into the store. LGB finds it difficult to enter dry maize.

from Wikipedia