马缨丹总岩茨烯对小菜蛾和斜纹夜蛾幼虫的拒食作用

Antifeeding effects of crude lantadene from Lantana camara on Plutella xylostella and Spodoptera litura larvae.

从马缨丹叶片中提取总岩茨烯,测定总岩茨烯对小菜蛾2龄幼虫和斜纹夜蛾1、2龄幼虫的拒食作用.结果表明,在非选择性试验中,1.6mg.ml-1的总岩茨烯对小菜蛾2龄幼虫和斜纹夜蛾1龄幼虫有拒食作用,48h的拒食率分别为62.4%和31.1%;在选择性试验中,0.4mg.ml-1的总岩茨烯即对小菜蛾2龄幼虫有拒食作用,0.4、0.8和1.6mg.ml-1浓度处理下的拒食率分别为52.7%、55.5%和78.9%;总岩茨烯只有在高浓度(1.6mg.ml-1)时,才对斜纹夜蛾1龄幼虫有拒食作用,拒食率仅为33.0%.在选择性和非选择性试验中,总岩茨烯对斜纹夜蛾2龄幼虫均无拒食作用.

In this study, crude lantadene was extracted from Lantana camara leaves, and its antifeeding effects on Plutella xylostella and Spodoptera litura larvae were tested. In no-choice test, crude lantadene at 1.6mg·ml^-1 concentration had antifeeding effects on the 2nd instar P. xylostella larvae and 1st instar S. litura larvae, with the antifeeding rate being 62.4 % and 33.1%, respectively within 48 h. In choice test, even a low concentration （0.4mg·ml^-1） crude lantadene still had anti-feeding effects on the 2nd instar P. xylostella larvae, and the antifeeding rate at 0.4, 0.8 and 1.6mg·ml^-1 concentration was 52.7 %, 55.5 % and 78.9 %, respectively. Crude lantadene only at 1.6 mg·ml^-1concentration had anti-feeding effects on the 1st instar S. litura larvae, and the antifeeding rate was 33.0 %. For the 2nd instar S. litura larvae, crude lantadene had no antifeeding effects both in no-choice and in choice test.