Effects of agrochemicals on life-history parameters of Aphidius gifuensis Ashmead (Hymenoptera: Braconidae)

Abstract

The contact and ingestion toxicities of selected agrochemicals applied at the standard field rate against adult females and pupae in host mummies of a native parasitoid Aphidius gifuensis were studied using several bioassays. Fresh residues of five insecticides (cartap, chlorfenapyr, emamectin benzoate, permethrin and imidacloprid) were found to be highly toxic against adult females as compared with the pupae in mummies. Evaluation of the residual effects of these five insecticides on cabbage foliage showed that cartap and imidacloprid were highly persistent. In the same assay, two IGRs (chlorfluazuron and lufenuron) and a fungicide (copper oxychloride) were harmless against adult females. When these agrochemicals were fed orally at the field rate, the mortality of adult females ranged from 13.3 to 46.7%. Ingestion of copper oxychloride had a slightly negative effect on parasitism.