Lesser grain borer in sorghum

The beetle is small (about 4 mm long), slender, cylindrical, polished dark brown or black, with a roughened wing surface

The head is turned down and covered by a hood-shaped thorax which bears small patches around the edge. Adults lay from 300 to 500 eggs singly or in clusters on grains or in powdery material over a period of 3-6 weeks. Eggs hatch in about 5-11 days into fleshy grubs, which appear swollen at the extremities and bore into grains and feed inside.

The larval period lasts from 25 to 50 days depending on the season.

Damage

This beetle pest is cosmopolitan in its distribution and infestation can be very heavy. It is also a serious pest on paddy, wheat, maize etc. The grub bores and feeds on the grain.

Management

Grain should be stored in a dry, clean condition in insect-proof containers. If keeping the grain dry is not practicable, fumigation with Aluminum phosphide tablets may be the only feasible protection.