Three new spring wheat germplasm lines are now available for breeding commercial wheat varieties resistant to the Hessian fly, Agricultural Research Service scientists report.

According to ARS geneticist Steven Xu, who is accepting seed requests, resistance in wheat is critical to stopping the fly, during its maggot stage, from feeding inside the plant, causing stems to buckle or stunting growth.

American farmers have been battling the one-eighth-inch-long, mosquito-like fly (Mayetiola destructor) since the Revolutionary War, when German auxiliary troops for the British, called Hessians, purportedly brought the pest to America in straw bedding. Today, M. destructor is a major insect pest of wheat in most states where the crop is grown. Though sporadic, Hessian fly outbreaks are costly, inflicting multimillion-dollar crop losses.

Adding to wheat growers' woes: The fly eventually overcomes the defenses of resistant varieties by evolving into new strains, or biotypes. The new wheat lines, dubbed "Synthetic Hexaploid Wheat" 8, 34 and 39 — all resist the Hessian fly Great Plains (GP) biotype. SW8 also resists the H13-virulent strain, according to Xu, who is in the ARS Cereal Crops Research Unit located in Fargo, N.D.

Xu collaborated with entomologist Marion Harris and geneticist Xiwen Cai of North Dakota State University (NDSU) at Fargo to evaluate the spring wheats' resistance to the fly.