Hessian fly is not a problem in oats. It is the immature, maggot stage of the Hessian fly that causes injury to plants. The maggot can damage seedlings in the fall and overwintered plants in the spring by rasping the lower stem tissue and sucking the sap which oozes from the wound.
How do I get rid of Hessian fly?
Foliar pyrethroid insecticides applied shortly after wheat emerges (at or before the two- to three-leaf stage) have been effective to manage Hessian fly. If applied at the right time, a pyrethroid will kill the adult flies and may also kill freshly hatched larvae before they become embedded behind the leaf sheaths.
What plants do Hessian flies form galls in?
Hessian fly, (Mayetiola destructor), small fly in the gall midge family, Cecidomyiidae (order Diptera), that is very destructive to wheat crops.