Residual selectivity of some pesticides on the predatory bug, Orius minutus (Hemiptera: Anthochoridae)

Abstract

ABSTRACT Orius species are predators of mites and many small insects such as aphids, scales, thrips, and insect eggs. Five insecticides (buprofezin, flonicamid, sulfoxaflor, flupyradifurone, and spirotetramat) and two acaricides (spiromesifen and emamectin benzoate) with low toxicity to natural enemies that are being used to control those pest groups were evaluated for their acute toxicity against adult females of Orius minutus (L.) (Hemiptera: Anthocoridae) and Orius laevigatus (Fieber) in a glass vial assay. Among the seven pesticides, spirotetramat and spiromesifen were the least acute toxic to both predators. In an experiment on sublethal toxicity of spirotetramat and spiromesifen against only O. minutus, we found that neither material negatively affected any of the life history parameters of O. minutus except for fecundity. A potted plant experiment was also conducted to confirm the efficacy of the combined use of spiromesifen and O. minutus against Tetranychus urticae Koch (Acari: Tetranychidae), and this combination was found to reduce the T. urticae population significantly more than the single treatment or untreated control. Therefore, we conclude that spiromesifen is a selective acaricide with less negative effect on biological parameters of O. minutus compared to other pesticides tested.