昆虫生长调节剂抑太保防治马尾松毛虫试验初报

应用抑太保防治马尾松毛虫4－5龄幼虫，24h后害虫开始死亡，第4天达到死亡高峰，第10天虫口校正减退率平均达84％以上；防治药剂费用3.0元/hm^2，具有见效快、防治成本低的优点，是一种防治马尾松毛虫的理想药剂。     

10%氟啶脲水悬浮剂润湿分散剂的筛选

采用流点法对10%氟啶脲水悬浮剂的润湿分散剂进行了初步筛选,在流点法筛选结果的基础上利用激光粒度仪测定粒径的方法对分散剂进行进一步的筛选。结果表明,农乳602、分散剂NNO、550S均能加工成流动性好的氟啶脲水悬浮剂,采用优化组合法和粘度法最终确定了10%氟啶脲水悬浮剂的润湿分散剂:农乳602和550S的比例为4:1,用量为0.8%。     

30%氟啶脲·溴虫腈悬浮剂的研制

对润湿分散剂增稠剂防冻剂等进行筛选得到30%氟啶脲窑溴虫腈悬浮剂的最佳制剂配方为院氟啶脲 26%溴虫腈4%,分散剂33SC 3.0%,分散剂NP-10 1.0%,农乳602#1.0%,硅酸镁铝1.5%,黄原胶0.2%,乙二醇 4.0%正辛醇0.2%,SAG-630 0.2%用水补足至100%通过湿式超微粉碎法加工工艺制成悬浮剂,制剂分散性良好, 悬浮率90%热贮和冷贮稳定性合格。     

Rate of decline of chlorfluazuron concentration in the fat of cattle

Objective To determine the rate of decline of chlorflu-azuron (CFZ) concentration in the fat of cattle.
Design A field depletion study.
Animals Fifteen steers that had become contaminated with CFZ through eating cotton trash or cotton leaf pellets derived from CFZ-treated cotton crops.
Procedure Fat samples were collected from the cattle at about 3 week intervals according to a schedule where each animal was sampled on four occasions up to 340 days after removal from the contaminated feed source.
Results When the effects of dilution are removed CFZ concentrations were found to decline slowly for about 200 days. Depletion was minimal between 200 and 340 days.
Conclusion According to this trial, CFZ-contaminated, non-lactating cattle which have finished growing will remain contaminated. Field experience has not supported this conclusion.     

灭幼脲和氟啶脲对斜纹夜蛾的毒力及其增效作用研究

在室内条件下测定了灭幼脲和氟啶脲对斜纹夜蛾(Prodenia litura Fabr)幼虫的毒力及其与5种增效剂的增效作用。结果发现,在3龄幼虫中,酯酶抑制剂TBPT对灭幼脲增效显著,SR值为8.58,羧酸酯酶抑制剂TPP增效6.04倍,谷胱甘肽转移酶抑制剂DEM增效4.22倍。多功能氧化酶抑制剂PB增效2.23倍,DDT脱氯化氢酶抑制剂DMC的增效作用最小,SR值为1.14,而在6龄幼虫中,以DEM对灭幼脲的增效作用最显著,SR值为6.4,其次为TBPT(5.93)>TPP(3.47)>DMC(1.49)。说明斜纺夜蛾对灭幼脲的解毒途径主要是水解作用,其次是氧化作用。就氟啶脲而言,5种增效剂无论是对3龄幼虫还是6龄幼虫,其增效比(SR)值和增效差(SD)值均无显著差异。     

广西小菜蛾对定虫隆的抗药性监测

从1997年下半年起,广西开始使用定虫隆防治小菜蛾。不同年份田间抗药性监测结果表明:2000年以前,小菜蛾对定虫隆仍敏感;2001~2002年小菜蛾对定虫隆的抗性指数为8.76~9.75,属低水平抗性;2003~2004年小菜蛾对定虫隆的抗性指数为20.41~21.25,已达到中抗水平;2002~2003年广西田间不同小菜蛾种群对定虫隆的抗性指数在11.43~28.14之间,达到中等水平抗性。在条件基本相同的情况下,田间药效试验结果为:2000年以前,5%抑太保乳油1 000~2 000倍液,药后7 d对小菜蛾的防效均在90%以上,2001年只有1 000倍液的防治效果达到90%以上,2002~2003年防效下降很快,到2004年,柳州、南宁试验点1 000倍液的防治效果均低于70%,显著低于前几年的防效。抗性监测与田间药效变化的结果基本一致。     

Developmental and tissue-specific expression of CHS1 from Plutella xylostella and its response to chlorfluazuron

The cDNA of chitin synthase-1 gene of Plutella xylostella (PxCHS1) was characterized and expression patterns of the two splice variants PxCHS1A and PxCHS1B were investigated in various developmental stages and in major body tissues by RT-PCR and real-time quantitative PCR (qPCR). The PxCHS1 cDNA was 5461 bp in length with an open reading frame of 4701 bp that encoded a putative protein of 1567 amino acids with predicted molecular mass of 179 kDa. The two splice variants were expressed from the mutually exclusive exons which were same in size (177 bp) but showed only 66% identity at the nucleotide level. Both splice variants were expressed in all developmental stages. The qPCR data suggested an uneven expression of the two variants in the body where expression of PxCHS1A was 3.7-fold higher than that of PxCHS1B. The expression of PxCHS1A was 1.5-fold higher in the head than the body whereas in case of PxCHS1B the difference between head and body was 6.3-fold. Chlorfluazuron did not change the expression of PxCHS1 in larvae.