多杀菌素和氟虫睛对瓢虫、寄生蜂和菜缢管蚜选择性的研究

Comparison on toxicity of fipronil and spinosad in Lipaphis erysimi and ladybirds or parasitoid wasps

采用药膜法研究了多杀菌素和氟虫睛对3种瓢虫、2种寄生蜂和菜缢管蚜的选择性。与菜缢管蚜相比,2种杀虫剂对3种瓢虫的毒性较低(LC50比值=1.73-41.9),尤其是氟虫睛对3种瓢虫以及多杀菌素对稻红瓢虫均具有较好的选择性(LC50比值大于5)。菜蚜茧蜂和蚜虫宽缘金小蜂对2种杀虫剂的敏感性远高于3种瓢虫和菜缢管蚜,2种杀虫剂对菜蚜茧蜂和蚜虫宽缘金小蜂均是高毒的(LC50比值=0.006-0.05)。3种瓢虫对多杀菌素和氟虫睛具有较高的耐药性,这将有助于其在生物防治中的应用。

The selectivity of insecticides to the field populations of the turnip aphid Lipaphis erysimi Kaltenbach （ Homoptera： Aphididae）, three predatory ladybirds and two parasitoid wasps, collected from Shangjie , Minhou County, Fujian, China, was determined by dry film method. As compared to L. erysimi, three predatory ladybirds （Coleoptera： Coccinellidae）, i.e., Propylaea japonica （Thunberg）, Chilomenes quadriplagiata （Swartz） and Verania discolor （Fabricius）, displayed significantly high tolerance to fipronil and spinosads. LC50 ratios （LRs） were 1.73 -41.9. In particular, with LRs higher than 5.0, fipronil showed lowly toxic to the three ladybirds and spinosads and imidacloprid to V. discolor. While, the susceptibilities to the two insecticides in two parasitoid wasps, i. e., Diaeretiella rapae （M＇ Intosh） （Hymenoptera： Aphidiidae） and Pachyneuron aphidis （Bouche） （Hymenoptera： Pteromalidae）, were far lower than those in the three ladybirds. The three insecticides were highly toxic to D. rapae and P. aphidis with LRs = 0.006 - 0.22. In view of very high tolerance to the two insecticides, inclusion of ladybirds for pest control in the integrated pest management studies were highly expected.