Non-target effects of insecticides commonly used against lepidopteran pests on the predator, Nesidiocoris tenuis (Reuter, 1895) (Hemiptera: Miridae), under greenhouse conditions

Abstract

Nesidiocoris tenuis (Reuter, 1895) (Hemiptera: Miridae) is the most widely used biological control agent of tomato pests, particularly tomato leafminer. Five treatments, spinetoram, chlorantraniliprole + abamectin, chlorantraniliprole + thiamethoxam, emamectin benzoate and dimethoate were tested on N. tenuis under greenhouse conditions in summer and autumn of 2018 in Malatya Province, Turkey. After insecticide application, N. tenuis were counted on days 1, 4, 7, 14, 21 and 28. The non-target effects of insecticides are classified according to IOBC toxicity categories. Spinetoram caused 24 and 52% mortality in summer and autumn experiments, respectively and is compatible with N. tenuis considering mortality in both seasons. Therefore, it is recommended for IPM. Chlorantraniliprole + abamectin was classified as slightly harmful in the summer experiment as it resulted in 45% mortality, however, in autumn conditions, it was resulted in 79% mortality and classified as harmful. This effect seen under cooler conditions should be consider in planning IPM. Chlorantraniliprole + thiamethoxam caused 62 and 63% mortality which was increasing up to the final day of autumn assessment, whereas emamectin benzoate caused high mortality of 86 and 87% in summer and autumn, respectively. Thus, it is concluded that these latter two insecticides are not compatible with N. tenuis .