Larvae feed inside the plant, stunting and reducing yields. High humidity is necessary for a significant infestation to develop. Therefore, injury is often more severe during years of abundant rainfall. Injury can occur either in the fall or spring. Once a field becomes infested, no chemical control measures will stop the injury.
Control is based entirely upon prevention and depends on good crop management.
Three cultural practices are recommended to reduce or avoid Hessian fly problems. Destroy volunteer wheat. Allowing volunteer wheat to grow for 2-3 weeks, especially during a wet summer, encourages development of a larger fly population. That population then can carry over into the regular crop planting. Volunteer wheat allows the population to increase and makes planting after the fly-free date less effective.