Note: Toxicity of some insecticides onBracon hebetor under laboratory conditions

Insecticides which were environmentally friendly and the least toxic, were screened against a laboratory strain ofBracon hebetor (Say) (Hymenoptera: Braconidae) for their suitability for release in IPM of cotton. Concentrations ranging from 1 to 1000 ppm of the formulated insecticides in acetone were applied in glass vials and also by a leaf method, whereby cotton leaves were dipped in aqueous solutions of the same concentrations of insecticides. Adult parasitoids were exposed in both methods. According to the LC₅₀ at 24 h exposure, Λ-cyhalothrin and spinosad were the most (7 and 5 ppm) and least (263 and 225 ppm) toxic in the vial and the leaf method, respectively, toB. hebetor. The possible use of the parasitoid for IPM of cotton is discussed. http://www.phytoparasitica.org posting July 20, 2006.     

新型微生物杀虫剂-Spinosad(多杀菌素)的毒理学研究进展

多杀菌素是一种大环内酯类化合物，由于其兼有生物农药的安全性和化学农药的速效性，而获得美国“总统绿色化学品挑战奖”。文章主要从多杀菌素对靶标昆虫的杀虫活性和对非靶标昆虫的毒性，多杀菌素的残留评价及分析检测方法，多杀菌素对昆虫的毒理机制等方面进行综述，并对多杀菌素的应用前景作了展望。     

10％多杀霉素·吡虫啉SC对茄子蓟马的田间药效评价

为明确10％多杀霉素·吡虫啉SC对茄子蓟马(Thrips tabaci Lindeman)的田间防治效果、使用剂量及施药适期及其对茄子生长的安全性,采用小区随机区组排列田间试验、邓肯氏新复级差法统计分析试验数据.结果表明,供试药剂10％多杀霉素·吡虫啉SC 30.0、37.5、45.0 g a.i./hm2处理,施药后1d的防效在79.2％～90.5％之间,施药后3d的防效在89.3％～94.5％之间,施药后7d的防效在90.4％～94.3％之间.与对照药剂相比,10％多杀霉素·吡虫啉SC高剂量45.0 g a.i./hm2施药后7d的防效与2.5％多杀霉素SC的防效相当,高于25％吡虫啉WP的防效.10％多杀霉素·吡虫啉SC对茄子蓟马具有良好的防治效果,且对茄子安全无药害,建议施药适期为茄子蓟马始发期,使用剂量为37.5-45.0 g a.i./hm2.     

蛋白饵剂对橘小实蝇辐照不育雄虫的引诱作用

以橘小实蝇为研究对象,研究蛋白饵剂对不同日龄、不同释放密度不育雄虫的引诱作用,以及施用蛋白饵剂后不同时间、添加多杀菌素对不育雄虫的引诱效果。结果表明,蛋白饵剂对不育雄虫的引诱率明显低于同日龄正常雄虫,5日龄时最高,分别为36.24%和48.93%,且随着日龄的增加,引诱率会不同程度下降。不育雄虫释放密度对引诱率无显著影响,0.25～1.00头/m2的释放密度下引诱率为33%～58%。不论是挂瓶法引诱,还是混入0.02%多杀菌素后点喷,蛋白饵剂对不育雄虫的引诱效果均随蛋白饵剂施用天数的增加而逐渐下降,挂瓶法前2d引诱的不育雄虫数量占总引诱数量的65%,添加多杀菌素法该比例则达到80%,5d后这2种方法不再有引诱效果。残留的多杀菌素对不育雄虫无触杀作用。