Hessian fly


  • Adult: Small, dark, leggy, two-winged insects that resemble mosquitoes.
  • Larvae: Reddish or white maggots that become stationary once they start feeding. Eventually, their skin hardens into a brown shell or "flaxseed."
  • Eggs: Small, slender and reddish. Laid end-to-end on the undersides of leaves. 

Timing of damage: Fall and spring

Type of damage: Stunted growth, often with thickened bluish-green leaves.

Scouting: Identify poor stands and check the base of the plant for maggots or "flaxseed" by pulling back the sheaths of several leaves.

Economic threshold: None established. However, planting fly-resistant varieties and planting after the fly-free date will help reduce the chance of infestation.

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