Grain Borer
Prostephanus Truncatus
Identification
Brown body colour. 1/16" to 3/16" in length. Antennae have 3 large segments at the end forming visible antenna clubs, reddish in colour. The humped thorax covers the head, its front rim has teeth–like indentations. Elytra (wing covers) are heavily punctated and drop off sharply at the back, giving the impression of a square end when seen from above.
Description
Adult beetle is a pest of stored maize, but also infests other types of grain. Larva bores tubular passages into the grain, typically making one main tunnel with smaller ones branching off. Brought in from tropical Central America in cassava roots and tapioca products, as well as in starchy fruits and tubers.
The female lays an average of 10 eggs on a grain of maize and the hatched larvae bore into the grain. The larva undergoes up to 4 development phases and pupates inside the corn grain. Lifecycles can be quite short, in good conditions (25 days at 34 °C, 75% relative humidity) there are several generations per year.
