Abstract Lethal and sublethal effects of imidacloprid and buprofezin on preimaginal and adult stages of the cotton whitefly parasitoid Encarsia inaron (Walker) (Hymenoptera: Aphelinidae) were investigated in the laboratory. Both insecticides significantly reduced adult emergence when parasitised nymphs, at either larval or pupal stages, were treated with field-recommended concentrations. Buprofezin had no significant effect on adult wasps. The LC 50 value of imidacloprid for E. inaron was 208.9 ppm. Adult longevity and the total progeny number were significantly affected only by imidacloprid when the larvae were treated. Both insecticides had a significant influence on parasitoid daily fecundity depending on the stage of the parasitoid at the time of treatment. Sex ratio of E. inaron offspring was significantly affected by the insecticides. Some life history parameters of the parasitoid were affected by application of the insecticides at the larval and pupal stages. However, neither of the insecticides significantly affected the life table parameters of treated adults. The implications of these results for the integration of biological and chemical control methods are discussed.