为测定3种植物提取物复配对松梢螟幼虫的联合毒力作用，并为开发此类植物源杀虫剂奠定理论基础。将乙醇作为溶剂提取3种植物中的有效活性成分。采用浸虫法在室内将博落回、柚子皮及垂序商陆提取物进行两两复配，测定了各复配剂对松梢螟幼虫的联合毒力作用，同时筛选出最佳的复配组合和比例。结果表明：博落回与柚子皮提取物复配的效果并不显著，仅在处理比例为1:5和5:1时表现出一定的相加作用；博落回与垂序商陆提取物复配效果在处理比例为1:3时表现出明显的增效作用，共毒系数(CTC)为147.52；柚子皮与垂序商陆提取物复配效果在处理比例为1:3时增效作用最为显著，共毒系数(CTC)为170.02。因此，3种植物提取物复配对松梢螟幼虫联合毒力最佳的复配组合和比例为柚子皮与垂序商陆，质量比为1:3。

The research aimed to determine the common-toxicity of the mixture of 3 kinds of plant extracts and provide theoretical basis for developing new botanical pesticide. With ethanol as extracting solvent, active components were extracted from 3 kinds of plant. The common-toxicity of the mixtures, which were respectively mixed with the plant extracts of Macleya cordata, Citrus maxima peels and Phytolacca americana L., to control the larvae of D. splendidella were tested in the laboratory by using impregnation method. The results showed that the effect of the mixed extracts of M. cordata and Citrus maxima peels wasn't significantly, but it had some additive function only when the mix-proportion were reached to 1:5 and 5:1. The mixed extracts of M. cordata and Phytolacca americana in mix-proportion of 1:3 had remarkable synergistic effects, and the common-toxicity coefficient (CTC) was 147.52. When Citrus maxima peels extracts mixed with P. americana extracts in mix-proportion of 1:3, the CTC reached to 170.02. The overall results indicated that the best mixture combination was C. maxima peels extracts and P. americana extracts, and the best mix-proportion was 1:3.