In order to evaluate the possibility of application of recommended pesticides in combination with using predatory bug, Onus albidipennis Reut. against vegetable pests, an experiment with completely randomized design (CRD) was carried out under controlled conditions. The study was conducted in laboratory, using “Drum cell” method recommended in IOBC guideline. Side-effects of amitraz, heptenophos, malathion and propargite were assessed on 4th instar nymphs. Similarly, side-effects of these pesticides except propargite were studied on adult stages. Based on their toxicity to 0. albidipennis, the pesticides were classified into four categories. In the study of side-effects of pesticides on 4th instar nymphs, amitraz and propargite were grouped in toxicity class 2 with 56.70% and 43.20% mortality rate respectively. Heptenophos was grouped in class 1 with 29.70% mortality and malathion in class 4 with 100% mortality. In studying the side-effects of pesticides on adults, amitraz and malathion were grouped in toxicity class 4 with 100% and heptenophos in class 2 with 47.90% mortality rate. None of the tested pesticides exhibited any adverse effect on fecundity and fertility of this insect.
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