Sorghum Midge, Contarinia sorghicola.
Adult midge on sorghum flower.
Panicles with blasted seed due to larval feeding.
This insect is problematic in southern states and affects southeastern Kansas. In tropical and subtropical regions it is considered one of the most serious pests of grain sorghum. The adult is a tiny, reddish-colored fly only 1/8 inch long. Eggs are laid in flowers at bloom. The pinkish larvae feed on ovaries of seeds and darken to reddish orange as they mature. Infested seeds may exude an orange juice when squeezed. When adults emerge, an empty, clear-colored pupal case may remain attached to the glumes. Accurate diagnosis frequently requires laboratory inspection. If you are in doubt, take a head sample to the local K-State Research and Extension office for submission to the entomology diagnostic lab. Avoid having sorghums blooming during mid- to late August, especially south of US Highway 54 (see map, page 9). Chemical control is only effective if it can be timed to coincide with the initial adult flight. Given the extensive scouting required to determine this, and the sporadic nature of the problem in Kansas, spray treatments are not advisable.
Page last updated on 10/31/2013 by J.P. Michaud.