A pupa moves to the tip of the glume as emergence nears. A sign of emergence is the whitish-cast skins protruding from the glume tip. The pupa stage requires 2 to 3 days before adults emerge. Damage The sorghum midge is found in all Mississippi counties where sorghum is grown. Its primary hosts include sorghum and Johnsongrass, but a few other grasses have limited suitability for midge development.
Sorghum is susceptible to damage from midge only during the bloom period.
The interval of blooming for a field depends on how uniform blooming occurs across a field. Once blooming begins, an individual head is susceptible to damage for 4 to 9 days. Adult midges do not damage sorghum. However, the female flies to blooming sorghum and crawls over seed heads in bloom in search of egg laying sites. The female sorghum midge deposits a single egg between the glumes of a floret.