银杏外种皮与垂序商陆叶提取物及二者复配剂对小菜蛾杀虫活性研究

Insecticidal activity of extracts of Ginkgo biloba sarcotesta and Phytolacca americana leaf and their mixture against Plutella xylostella

为更好开发利用垂序商陆与银杏两种植物资源,本研究对银杏外种皮(Ginkgo biloba sarcotesta,Gbs)及垂序商陆叶(Phytolacca americana leaf,Pal)提取物的单方及复配剂对小菜蛾的杀虫活性进行了测试和比较。结果发现,银杏外种皮与垂序商陆叶提取物均能对小菜蛾表现出良好灭杀活性,且灭杀活性随处理时长及提取物浓度的增加而增加,各浓度下银杏外种皮提取物的小菜蛾杀虫活性均优于垂序商陆叶提取物,8 mg/mL浓度下处理72 h后二者的小菜蛾校正死亡率分别为74.7%(Gbs)与64.8%(Pal);二者毒力回归方程分别为y=1.584x-1.243(Gbs)与y=1.337x-0.629(Pal),LC50分别为2.95 mg/mL(Gbs)与6.09 mg/mL(Pal);复配剂的小菜蛾灭杀活性随二者配比变化而变化,最佳配比为1∶11(Pal∶Gbs),LC50为1.24 mg/mL(低于二者各自单方的LC50,毒力指数为491.13 mg/mL(明显高于二者单剂毒力指数之和),共毒系数为152.92(表明复配增效作用明显)。研究结果可为利用垂序商陆叶与银杏外种皮协同开发新型生物农药提供实验依据。

In order to have a better exploitation and utilization for Phytolacca americana and Ginkgo biloba sarcotesta,the insecticidal activity of the extract of Phytolacca americana leaf(Pal)and Ginkgo biloba sarcotesta(Gbs)and their mixture against Plutella xylostella were tested and compared in the present paper.Results showed that,both of the two kinds plant extracts showed good insecticidal activities against Plutella xylostella,and the activity raised with the increasing of treating time and extract concentration.The extract of Gbs performed better than that of Pal at all concentrations,and the corrected mortality were 74.7%(Gbs)and 64.8%(Pal)after 72 hours treatment with 8 mg/mL concentration.The virulence regression equation were y=1.584x-1.243(Gbs)and y=1.337x-0.629(Pal)while the LC50 were 2.95 mg/mL(Gbs)and 6.09 mg/mL(Pal).The insecticidal activity of the two extracts’mixture varied with the mixing ratio and the optimum ratio was 1∶11(Pal∶Gbs).The mixture’s LC50 was 1.34 mg/mL which was lower than that of both single extract while the virulence index was 491.13 mg/mL which was higher than the sum of two single extracts’virulence index.The co-toxicity coefficient value of 152.92 suggested a significant synergistic effect existed in mixing treatment.These results could provide some references for the new bio-pesticides exploitation based on the extract of Pal and Gbs.