Pest Profile

Hessian Fly
Mayetiola destructor (Say)
  • Hessian fly adult
  • Hessian fly pupa, resembling flax seeds, at the crown of the plant
  • Hessian fly damage
  • Hessian fly pupa

Pest Description

The adult hessian fly is an eigth of an inch long, dark in color, and resembles a gnat in appearance. Adults become active in fall and lay eggs on the surface of leaves (resembling leaf rust) on wheat seedlings. Hessian fly maggots hatch and move to the base of the plant where they feed between the leaf sheath and stem. Hessian fly overwinters as a pupa, which is termed 'flaxseed' because it is dark red and shaped like a flaxseed. Infested tillers typically die over the winter. Some adults emerge in spring and others emerge in the fall after pupa remain dormant over the summer. Spring damage from larvae causes stem lodging. 


Source of information

S. Bauer (ARS/USDA and Univ. of Kentucky IPM Training Slide Set), Kevin Black (Growmark), Department of Entomology (University of Nebraska - Lincoln), Chen Lab (Dept. of Entomology, Kansas State University), R.L. Croissant (

Pest Diagnostics


Pest photo source

Phil Sloderbeck, KSU Entomology

Plant Diagnostics


Plant diagnostic image(s) source

Chen Lab (Dept. of Entomology, Kansas State University)