Side effects of fungicides and insecticides on predatory mites, in laboratory conditions

Experiments were carried out on the toxicity of selected insecticides and fungicides to the predatory mites species: Amblyseius swirskii, A. andersoni, and Phytoseiulus persimilis. Among the tested active substances: abamectin, hexytiazox, and spinosad were safe to the predators. The mortality level of the tested predator was comparable to the control treatment, seven days after application. The percentage values of these predatory mites’ mortality caused by these insecticides, applied at one and a half of the recommended dose did not exceed a low toxicity – 25% (referring to International Organisation for Biological and Integrated Control (IOBC) classification on the toxicity to beneficial organisms). The results of the tests revealed that imidaclopryd, lambda-cyhalothrin, and fenpyroksymat were highly toxic to the predatory mites. It was found that toxicity of fungicides to the tested predatory mite species depended on the date of the chemical treatment and the date the predators were introduced. The fungicide Topsin M 500 SC – thiophanate-methyl, appeared to be selective to the species A. swirskii and it could be used in the Integrated Pest Management (IPM) programs for greenhouse grown crops.