Abstract:

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.