小菜蛾对菊酯类农药抗性水平及高效农药应用研究

室内试验彩和叶片浸渍法，对江苏五个地区的小菜蛾进行毒力及抗性测定比较。结果表明江苏南京、扬州等菜区小菜蛾对三种拟除虫菊酯已产生高抗水平的抗性，抗性倍数74．03－324．13。小菜蛾对溴氟菊酯、氰戊菊酯、DDVP、快灵表现不同程度的交互抗性；对杀虫双、氟铃脲、宝路不产生交互抗性；对锐劲特、灭虫灵为负交互抗性。筛选出高效、低毒、无公害的单剂6个，复配剂3个。灭虫灵、锐劲特、氟铃脲、抑太保、宝路、杀虫双对小菜蛾具有很高的活性，LC50为0．018－71．83ppm。田间试验结果，灭虫灵8ppm防效95％以上，持效期10天；氟铃脲50ppm，前期药效表现慢，7－10天达90％以上。三个复配剂中以灭虫灵与高效氯氰菊酯复配药效与速效表现突出，10ppm12－15天药效95％以上，其它两个复配剂见效较慢，5－10天的防效90％以上。

Resistance level of Plutella xylostella to Permethrin and application of Permethrin

Toxicity of seveal Permethrins to Plutella xylostella and resistance of Plutella xylostella to Permethrin was conducted from different regions of Jiangsu. The results showed that resistance level of Plutella xylostella to three kinds of Permethrins had been high in the main vegetable regions of Jiangsu. Plutella xylostella had different degree of cross-resistance to Deltamethrin, Cypemethrin, DDVP and Methomyl, but no cross-resistance to Dimenypo, Fulingniao and Diafenthiuron, and had negative cross-resistance to Fipronil and Avermectin. Six single and three mixture insecticides with high effect and low toxicity were selected. Avermectin, Fipronil, Fulingniao, Chlorfluazron, Diafenthiuron and Dimenypo had high activity to Plutella xylostella with LC 50 of 0.018-71.83ppm. Field experiments showed that Avermectin with 8ppm had above 95% killing effect for 10 days. Among three mixtures, the efficacy and the speedy effect of the Avermectin+Alphcypermethrin was outstanding.