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

Resumen

Whiteflies, the tomato borer and leafminers are among the major pests of greenhouse tomatoes in Spain. Macrolophus pygmaeus (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 front of those major biological control agents. Potted tomato plants kept in a greenhouse were sprayed with the highest recommended field rate of emamectin benzoate (14.25 mg L –1 ), and the toxicity of fresh and 7-day-old residues to adults of the three biological control agents were studied to ascertain their compatibility. The results demonstrated the compatibility of both fresh and 7-day-old residues with the three species of natural enemies.