摘要 : The aim of this study is to investigate fumigant toxicity of Datura metel extracts on Callosobruchus maculatus. Datura metel leaf powder was extracted with hexane, ethyl acetate, acetone, chloroform and methanol and tested at 50, ... 展开 The aim of this study is to investigate fumigant toxicity of Datura metel extracts on Callosobruchus maculatus. Datura metel leaf powder was extracted with hexane, ethyl acetate, acetone, chloroform and methanol and tested at 50, 100 and 150 mu l concentrations. Adult mortality, oviposition detterent, infestation, tolerance, weight loss and seed germination were calculated and analysed using statistical tool (ANOVA). At 24 h of exposure, ethyl acetate had the highest significant mortality (50.75% and 89.67%, respectively) with the least LC50 (0.03 mu l) recorded at 72 h. Per cent egg hatchability was highest, in control (93.33%), lowest in ethyl acetate (8.33%) at 150 mu l concentration and had highest reduction in adult emergence at 50 (55.38%), 100 (86.67%) and 150 mu l (93.33%), respectively. There were 100% tolerance in the control and 63.60-75.55% tolerance at 150 mu l, in treated dishes resulting in significantly (p < 0.05) highest weight loss (17.14%) compared to treated grains. The percentage seed germination of treated grains was significantly higher (p < 0.05) than the control. Ethyl acetate proved to be the most effective and analysed by GC-MS. Phytol (22.57%), 2-Isopropyl-5-methylphenol (thymol) (15.98%), Cyclohexanol, 2-methyl-5-(1-methylethyl)-, (1 alpha,2 beta,5 alpha)- (10.47%), 6,10,14-Trimethy-2-pentadecanone (7.32%) and 4, 8-Dimethyl-3,8-dien-2-one (4.82%) were identified as the main bioactive constituents. Datura metel ethyl acetate extract exerted good toxicity on C. maculatus and can be used as biofumigant to protect cowpea against infestation and seed damage to reduce the hazards related to the use of synthetic insecticides. Further research work is suggested to evaluate the effect of the extract on the insect biochemical activities. 收起