EFFECTS OF A NEEM SEED EXTRACT (AZADIRACH TA-INDICA A JUSS) ON THE DEVELOPMENT OF THE DERMAPTERA, FORFICULA-AURICULARIA L

Young nymphs and adults of the European earwig, Forficula auricularia L., were exposed in the laboratory and in the field to an extract from seed kernels of the neem tree, Azadirachta indica A. Juss. No effect was observed on mortality, weight, food intake or fecundity of adults when treated directly in the laboratory with 50 ppm of azadirachtin. N one of the second instar nymphs treated by contact with the fresh resi due or fed on medium treated with 25, 50, or 250 ppm of the product co uld achieve their development. The nymphs exhibited a decrease of food intake and of ponderal growth a few days after the treatment, as well as an increase of the intermoulting delay. Behavioural tests revealed no repellent or antifeedant effect of the product. Applications in pe ach tree orchards resulted in a 70% reduction of nymphal population of earwigs. Neem products could be used to reduce earwig populations if applied when young instars are present. They should therefore be avoid ed during this period on crops where these insects need to be preserve d because of their predation on aphids.