Dale Whaley
Assistant Professor

Whaley, D.*1,
1 Assistant Professor, WASHINGTON STATE UNIVERSITY EXTENSION, Waterville, WA, 98858

The Hessian fly Mayetiola destructor (Say) (Figure 1), is considered one of the oldest and most damaging insect pests to wheat (Triticum spp. L.). Originally from Asia, it is believed to have been introduced in straw bedding used by Hessian troops during the Revolutionary War, hence its name. From this initial introduction in the Long Island, New York area, the fly quickly spread from farm to farm, destroying entire wheat fields (Pauly 2002). Since then, this pest can be found throughout major wheat-producing regions in both the United States and Canada. Here in Washington State, a wheat pest survey conducted in 2015 detected Hessian fly densities in Adams, Stevens, and Whitman counties at levels below economic thresholds. Even though it was detected in small numbers, producers should be able to recognize this pest, know how to sample for it, and manage it when or if outbreak numbers are detected. However, in 2017, pest numbers were detected in high numbers, resulting in economic damage around the Ritzville area.