Abstract
Extensive use of pesticides in public health and agricultural programs has caused many environmental problems as well as toxic effects on non-target organisms including predatory mites. This study has been conducted to determine toxic effects of two acaricides; oxamyl and pyridaben at their three different concentrations. Effect of spray was observed on eggs, immatures and adults of seven predatory mites; Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae), Amblyseius cydnodactylon (Shehata and Zaherand), Phytoseius plumifer (Canestrini and Fanzago), Typhlodromps swirskii (Athias-Henriot), Euseius scutalis (Athias-Henriot), Neoseiulus barkeri (Hughes) (Acari: Phytoseiidae) and Agistemus exsertus (Gonzalez) (Acari: Stigmaeidae) under laboratory conditions. Immature stage of these predatory mites was found to be more susceptible than adults to both oxamyl and pyridaben. The latter was found to be more toxic to immatures and adults than oxamyl. Effect of both pesticides on hatching was found to be insignificant because more than 50% of their eggs were successfully hatched even at the DRD. This study has shown that oxamyl and pyridaben can disrupt biological control due to their toxicity to predatory mites, so extra care must be taken with over application of these acaricides.