桑叶提取物1-DNJ对甜菜夜蛾幼虫生物活性的影响

目的]为桑叶植物源农药的开发提供科学依据。方法]以甜菜夜蛾为研究对象，利用桑树叶片提取物1-DNJ饲喂甜菜夜蛾4龄幼虫，研究1-DNJ对甜菜夜蛾拒食、触杀、胃毒和生长等生物活性的影响。结果]1-DNJ浓度为0．25g／L，48h检测的拒食率高于69％，浓度为2．00g／L时拒食率达到99％以上；1-DNJ浓度越大，对甜菜夜蛾幼虫的生长发育抑制作用越明显，1．00g／L处理的试虫体重在48和72h均较24h时低，出现负增长。随着1-DNJ浓度的升高，甜菜夜蛾化蛹率显著下降，但对甜菜夜蛾的蛹重作用不大。1-DNJ对甜菜夜蛾的触杀和胃毒作用效果不如其对拒食和生长抑制的作用明显。结论]桑叶1-DNJ主要通过拒食作用影响甜菜夜蛾生长，进而达到防控的目的．

Effect of 1-DNJ from Mulberry Leaves on the Biological Activity of Spodoptera exigua Hubner

Objective ] The study aimed to provide scientific basis for developing mulberry plant source pesticides. Method ] Bioassays in laboratory were employed to investigate anti-feeding, growth inhibitory functions of 1-DNJ extracted from mulberry leaves on the 4th S. exigua Result] The resuh showed that the highest anti-feeding rates were over 69 and 99% respectively at 48h, when concentration of 1-DNJ were 0.25 g/L and 1.00 g/L, respectively. The insect weight in 48 h and 72 h were less than 24 h and showed negative growth. The developmental inhibition assay indicated that weight and pupatation rates decreased with the increasing 1-DNJ concentration. While, the pupal weight of 4^th S. exigua non-distinctive inhibited. However, the mortality rates of contact toxicity and stomach toxicity were less than anti-feeding and growth inhibitory effect. Conclusion] These results implied that mulberry was treasuries of bioactive substances useful as pesticides.