Evaluation of the effect of different insecticides on the survival and capacity of 2 Eretmocerus mundus Mercet to control Bemisia tabaci (Gennadius) populations

Abstract

Two different experiments were carried out to evaluate three insecticides. In the 24 first one, the effect of two insecticides, methomyl and indoxacarb, on pupae and 25 adults of the whitefly Bemisia tabaci (Gennadius) parasitoid Eretmocerus mundus 26 Mercet was evaluated under laboratory and greenhouse conditions, using sweet 27 pepper (Capsicum annuum L.) plants. In the second experiment, oxamyl was 28 tested to study its effect on the ability of E. mundus to parasitize and control B. 29 tabaci in sweet pepper plants, using a greenhouse cage evaluation. Methomyl and 30 indoxacarb caused low mortality of E. mundus pupae (17.6 and 7.8% 31 respectively), although methomyl mortality was significantly higher. Methomyl 32 produced 100% mortality on E. mundus adults with fresh and 24 hour-old 33 residues on leaves, significantly higher than the mortality produced by indoxacarb 34 (values ranged from 43.9 to 34.4%). The harmful effect of methomyl persisted for 35 a long time (up to 60 days). The results of the experiment with oxamyl showed 36 that E. mundus controlled whitefly population, without significant interaction 37 between the presence of the parasitoid and insecticide on whitefly mortality. 38 Whitefly mortality in the presence of the parasitoid was 87.8%, significantly higher 39 than the mortality in the absence of E. mundus (59.3%). Oxamyl did not produce 40 a significant effect on the emergence of E. mundus adults. Application of the 41 products in IPM programs is discussed.