|source image: ento.okstate.edu|
The sorghum midge attacks sorgos, grain s, Sudan grass, and other members of the sorghum group. This insect is more prevalent in the southern are sorghum of sorghum culture than in the northern states. It is the most destructive of all the insects that attack the grain sorghums,
The sorghum midge appears in the spring as a small, red adult fly. It lives on plants of Johnson grass until sorghum reaches the heading stage. The flies lay their eggs inside the flower at the time of blossoming. The eggs hatch into small, white, headless larvae that feed on the juices of the developing seed. As a result the seeds fail to develop, and there is general blasting of the spikelets. The larvae grow rapidly, pupate and soon emerge again as adult flies to complete their cycle. A new generation is usually produced every two or three weeks. The insect overwinters in plant refuse in the larval stage.
How to control sorghum midge?
Damage caused by the sorghum midge can be reduced by (a) burning and plowing under of old crop refuse in the fall or early spring before the adult flies emerge, (b) cultivation or elimination of near-by stands of Johnson grass which harbor the insect early in the season, (c) restricting planting to a single variety of sorghum, thus reducing the time during which infections can occur as well as the insects’ food supply, and (d) early planting in the spring so plants can make a good growth before infestations become heavy.
The sorghum midge is also controlled to a certain extent by parasitic insects. Although these parasitic insects reduce the population of the sorghum midge, they unfortunately are not so effective as would be desired because they make their appearance later in the season at a time when the crop has already been damaged by the midge.