Application of pheromone traps for managing Hessian fly, (Diptera: Cecidomyiidae) in the Southern Great Plains

Authors: KNUTSON, ALLEN - Texas A&M Agrilife; GILES, KRISTOPHER - Oklahoma State University; ROYER, THOMAS - Oklahoma State University; Elliott, Norman - Norm; BRADFORD, NATHAN - Oklahoma State University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2017
Publication Date: 4/26/2017
Citation: Knutson, A.E., Giles, K.L., Royer, T.A., Elliott, N.C., Bradford, N. 2017. Application of pheromone traps for managing Hessian fly, (Diptera: Cecidomyiidae) in the Southern Great Plains. Journal of Economic Entomology. 110(3):1052-1061.

Interpretive Summary: The Hessian fly is an important pest of winter wheat in the Southern Great Plains of the U.S. As larvae feed behind the leaf sheath, infestations often go undetected until crop damage is evident and there are no remedial actions that can prevent economic loss once a field is infested. The recent discovery of the sex attractant pheromone of the Hessian fly provides an opportunity to use pheromone traps to detect and monitor adult activity and potentially better manage this pest. Adult male Hessian fly activity was monitored during four years at six locations from north central Oklahoma to central Texas. In Oklahoma, trap captures were low in the fall, no flies were captured during the winter, and the largest number of flies was captured in the spring. In south central Texas, adults were captured throughout the fall, winter and in the spring when trap captures were again the greatest. At southern locations the number of adults captured during January and February was significantly correlated with the number of larvae per stem at crop maturity. Although large numbers of adults were often captured in traps economic infestations of larvae rarely developed. Pheromone traps were found to be a reliable method to monitor Hessian fly activity throughout the season and may be useful in identifying fields at risk to economic infestations. Early detection is important because there are no effective methods to control Hessian fly larvae in wheat with insecticides once they become established in their feeding sites behind leaf sheaths.

Technical Abstract: The Hessian fly, Mayetiola destructor Say, is an important pest of winter wheat in the Southern Great Plains of the U.S. As larvae feed behind the leaf sheath, infestations often go undetected until crop damage is evident and there are no remedial actions that can prevent economic loss once a field is infested. The recent discovery of the sex attractant pheromone of the Hessian fly provides an opportunity to use pheromone traps to detect and monitor adult activity and potentially better manage this pest. Adult male Hessian fly activity was monitored during four years at six locations from north central Oklahoma, 36°N latitude, south to central Texas 31°N latitude. In Oklahoma, trap captures were low in the fall, no flies were captured during the winter, and the largest number of flies was captured in the spring. In south central Texas, adults were captured throughout the fall, winter and in the spring when trap captures were again the greatest. The relationship between trap captures and density of Hessian fly larvae per tiller were investigated during the fall and spring. At the two southern locations, the number of adults captured during January and February was significantly correlated (R2=0.66) with the number of larvae per stem at crop maturity. Although large numbers of adults (>100/trap/day) were often captured, economic infestation of larvae rarely developed. Pheromone traps were found to be a reliable method to monitor Hessian fly activity throughout the season and may be useful in identifying fields at risk to economic infestations.