Wheat Insects

Hessian Fly, Mayetiola destructor.

Adult Hessian fly on stem.

'Flax seed' pupae on wheat crown.

The Hessian fly occurs in most areas of the state, but damaging populations are more common in central and eastern Kansas. Injury is usually more serious during years of abundant rainfall. Damage occurs in the fall and spring. There are no remedial measures that can be applied after a field is infested.

Recent infestations have often been associated with wheat planted no-till, directly into the previous year’s wheat stubble. Fall infested plants have a characteristically thickened, dark bluish-green appearance. Infested tillers die off over the winter. Hessian flies overwinter in wheat as pupae commonly called flax seeds. Noticeable fall infestations signal potentially serious yield reductions in the spring, because the fall generation serves as a springboard for the generation that causes lodging.

Hessian fly can cause plants to lodge in the spring, usually just above a node. If Hessian fly is responsible for the lodging, larvae or pupae will be present on the stems when the leaf sheaths are carefully stripped away to expose the stems. No treatment is possible at this time, but significant lodging would suggest that more attention should be given to using resistant varieties or delaying planting for next wheat crop.

Control is usually based on prevention and depends upon sound management and area-wide cooperation. The important elements of fly management include: (1) planting resistant varieties where problems have occurred, especially when planting very early or very late; (2) destroying volunteer wheat; and (3) planting after the 'fly-free' planting date for your county. Seed treatments carry label claims for early season protection and may have application in fly-prone areas when planting susceptible varieties before the fly-free date. However, the risk of infestation is usually difficult to predict. Seed treatments will not provide protection against spring broods.

Winter wheat variety ratings for Hessian fly resistance are available in KSRE publication MF-991: Wheat Variety Disease and Insect Ratings.

For more detailed information on the biology of the Hessian fly, see KSRE publication MF-1076: Hessian Fly.

Page last updated on 10/30/2013 by J.P. Michaud.