Effects of amitraz on the parasitoid Encarsia formosa (Gahan) (Hymenoptera:Aphelinidae) for control of Trialeurodes vaporariorum westwood (Homoptera: Aleyrodidae): IOBC methods

Abstract

The side effects of amitraz at three rates (the maximum recommended field concentration, 1/2 and 1/4 the maximum recommended field concentration) on Encarsia formosa were tested in the laboratory using the IOBC classification. The pupal mortality, fecundity and longevity of the parasitoid wasps exposed to pesticide were determined. Results showed that there is a significant difference in pupae mortality between the treatments and the untreated control group, but we did not observ adverse effects on fecundity and longevity. According to the IOBC classification, amitraz at the maximum recommended field concentration (E=89.09) and 1/2 dose (E=82.3) were found to be harmful and 1/4 dose (E=63.2) was moderately harmful for E. formosa. We concluded that amitraz is unsafe for E. formosa and it can not be used for integrated pest management in integration with E. formosa to control Trialeurodes vaporariorum.