3种植物提取物复配对小菜蛾的生物活性

为了研制高效低毒的植物源杀虫剂,有效控制小菜蛾的危害,采用浸虫法测定了苦参、川楝子和百部提取物对小菜蛾的杀虫活性,并结合正交试验设计方法,测定了不同提取物配比对小菜蛾的室内联合毒力,从而筛选最佳复配比例.结果表明,苦参、川楝子和百部提取物均对小菜蛾具有一定的杀虫活性,其半数致死剂量( LC50)分别为74.07 mg/...

Bioactivity of Mixtures of Three Plant Extracts against Plutella xylostella

In order to control the damage of Plutella xylostella effectively,a new style and high active plant insecticide was studied.The bioactivities of extracts from Sophora flavescens,Melia toosendan Sieb and Stemona sessilifolia against Plutella xylostella were determined by larva-dropping method.The virulence activity test combined with orthogonal experimental design me-thod was used to study the common-toxicity of the mixture to select the best mixture ratio.The results showed that the extracts from S.flavescens,M.toosendan Sieb and S.sessilifolia had pesticidal activity against P.xylostella,and the LC50 were 74.07mg/L,58.64mg/L,86.97mg/L,respectively.The mixture had the strongest effect on P.xylostella and its mortality rate reached 98.8% when the extract of S.flavescens was mixed with that of M.toosendan Sieb and S.sessilifolia in mix-proportion at mass concentration of 6∶5∶6.