hessian fly

Tiny black fly, a species of gall midge that feeds on wheat and is considered a serious pest of winter wheat in the USA and New Zealand.

Classification The hessian fly Mayetiola destructor belongs to the family Cecidomyiidae (suborder Nematocera) of order Diptera, class Insecta, phylum Arthropoda.

Hessian flies lay their eggs on the top surface of leaves of young wheat. The larvae feed on the leaf sheaths and also suck the plant sap. Wheat infested during the autumn appears stunted and the leaves are dark bluish-green. Intensely parasitized plants die during the winter.

The use of resistant wheat varieties in combination with delayed planting in the autumn (observing ‘fly-safe’ dates) has greatly reduced the damage caused by hessian flies in most wheat-producing areas of the USA.

Other allied pests include the sorghum midge Contarinia sorghicola, and the clover seed midge, Dasyneura leguminicola. The sorghum midge is a serious pest in the southern USA and the more humid areas of the Gulf States.