Short communication. Toxicity of emamectin benzoate to adults of Nesidiocoris tenuis Reuter, Macrolophus pygmaeus (Rambur) (Heteroptera, Miridae) and Diglyphus isaea Walker (Hymenoptera, Eulophidae) on tomato plants. Semi-field studies

Abstract

Whiteflies, the tomato borer and leafminers are among the major pests of greenhouse tomatoes in Spain. Macrolophuspygmaeus (Heteroptera, Miridae) and Nesidiocoris tenuis are polyphagous predators of whiteflies, the tomato borer and other pests. Diglyphus isaea (Hymenoptera, Eulophidae) is an ectoparasite of leafminers. These three natural enemies are commonly released in the commercial horticultural  greenhouses of south-eastern Spain. Emamectin benzoate is a new semi-synthetic derivative of the avermectin B1 developed for Lepidoptera pest control in vegetable crops, with requested inclusion in annex I of the EU directive 91/414/EEC. As for any new insecticide that is being introduced for its use in protected tomato, it is critical to understand the level of compatibility of emamectin in frontof those major biological control agents. Potted tomato plants kept in a greenhouse were sprayed with the highestrecommended field rate of emamectin benzoate (14.25 mg L–1), and the toxicity of fresh and 7-day-old residues toadults of the three biological control agents were studied to ascertain their compatibility. The results demonstrated thecompatibility of both fresh and 7-day-old residues with the three species of natural enemies.