Effectiveness of insecticides against Thrips tabaci collected from onion- and scallion-producing areas in Hyogo Prefecture

Abstract

We investigated the effectiveness of 10 insecticides against Thrips tabaci collected from six onion fields and three scallion fields in the onion- and scallion-producing areas of Hyogo Prefecture. In all fields, over 90% of the thrips died from exposure to asephate, prothiofos, fluxametamide, and flometoquin, while approximately 70% to 90% died upon exposure to thiocyclam and cyantraniliprole. However, cypermethrin, acetamiprid, spinetoram, and pyridalyl showed varying levels of effectiveness depending on the field and the effectiveness was low, especially in the scallion fields and in the onion fields located near the scallion fields. Interestingly, the effectiveness of these insecticides was similar in both fields.