马缨丹总岩茨烯对小菜蛾和斜纹夜蛾幼虫的拒食作用

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，1.6 mg·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，48 h的拒食率分别为62.4%和31.1%;在选择性试验中，0.4 mg·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1.6 mg·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（1.6 mg·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.

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

In this study, crude lantadene was extracted from Lantana canmara leaves, and its antifeeding effects on Plutella xylostella and Spodoptera litura larvae were tested. In no-choice test, crude lantadene at 1.6 mg x 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 (0.4 mg x 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 1.6 mg x ml(-1) concentration was 52.7%, 55.5% and 78.9%, respectively. Crude lantadene only at 1.6 mg x ml(-1) concentration 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.