Serious infestations of sorghum midge are relatively uncommon in Tennessee, but they can be very damaging. Sorghum midge is a small, gnat-like insect that is reddish-orange and about 1/10-inch long. Female sorghum midges lay eggs only during the bloom stage. Eggs are laid in the spikelets between the glumes of a floret. The larvae feed on the developing seeds, causing them to dry up and die.

Once grain heads are present, check for sorghum midge throughout bloom every 4-5 days. You can visually look for the reddish-orange flies, but a preferred method is to place a clear plastic bag over the head and shake, looking for midges that land on the plastic. Examine a minimum of 50 heads field in randomly selected areas of the field.

During flowering, once 20-30% of heads are blooming, treat when an average of one midge is found per head. More than one treatment may be needed in some cases.

Management options

Insecticide (Trade Names) for SORGHUM MIDGELb Active Ingredient per AcreAmount Formulation per AcrePerformance Rating
methomyl (Lannate LV 2.4)0.225 - 0.4512 - 24 oz6
esfenvalerate (Asana XL 0.66)0.015 - 0.032.9 - 5.8 oz8
spinosad (Blackhawk 36% WDG), suppression0.034 - 0.0741.5 - 3.3 oz5?
β-cyfluthrin (Baythroid XL 1)0.008 - 0.011 - 1.3 oz8
γ-cyhalothrin (Declare 1.25)0.0075 - 0.010.77 - 1.02 oz8
λ-cyhalothrin (Warrior II 2.08)0.015 - 0.020.92 - 1.23 oz8
Z-cypermethrin (Mustang Maxx 0.8)0.008 - 0.0251.28 - 4 oz8
  • Insecticide applications are made to control adults and prevents egg laying because larvae are hidden from insecticides.
  • Planting early, before mid-May, may help avoid some damage from sorghum midge.
  • Sorghum midge are often worse in sorghum next to earlier maturating fields that serve as a source of infestations.
  • Johnsongrass is an alternative host that may serve as a nursery for sorghum midge. Maintaining good weed control in and around a field can reduce infestations.