Thermal kill of wheat midge and Hessian fly

Abstract

Heat treatment effects on the survival rate of the wheat midge ( Sitodiplosis mosellana [Gehin]) and Hessian fly ( Mayetipla destructor [Say]) were studied by exposure of wheat midge larval cocoons to 90, 80, 70, 60, 55, 52.5, 50, and 47.5°C temperatures in a convection oven. Cocoons did not survive temperatures 55°C and higher when exposed for 3 min. Wheat midge larvae were killed at 52.5°C in about 7 min. At 47.5°C, some larvae survived for 26 min but were dead when the exposure time was extended to 37 min. Comparison of mortality of wheat midge larvae and Hessian fly showed no difference in response to 50 to 90°C. Effects of heat treatment on the two species were similar suggesting thermal treatment of the wheat midge could be applicable to the Hessian fly.