【摘要】 在本实验室前期工作中,发现生长于青藏高原的有毒植物瑞香狼毒对菜青虫具有较好的防治效果。采用微量点滴法研究瑞香狼毒素对菜青虫的触杀活性,以叶片夹毒法和灌喂法研究胃毒活性。在触杀活性试验中,72h 的致死中量(LD₅₀)为0.96μg/头,以6.25×10³ mg·L^-1浓度的样品液2μL 点滴试虫,即1.25×10μg/头处理组的72h 校正死亡率为92.2%。在胃毒活性试验中,72h 叶片夹毒法的致死中浓度(LC₅₀)为3.82×10³mg·L^-1,5.00×10⁴ mg·L^-1浓度处理组校正死亡率为91.2%;72h 灌喂法的 LD₅₀为3.80μg/头,以5.00×10⁴mg·L^-1浓度的样品液2μL 灌喂试虫,即1.00×10²μg/头的处理组的72h 校正死亡率为96.8%。结果表明,瑞香狼毒素对菜青虫具有较好的触杀活性和一定的胃毒活性。更多还原

【Abstract】 The contact toxicity and stomach toxicity of extract from the root of Stellera chamaejasme against the larvae of Pieris rapae was tested.The experimentation on contact toxicity was conducted with micro topical application.In 72h,the median lethal dose (LD₅₀) is 0.96μg/larvae and the corrected mortality of the larvae treated with 1.25×10 μg/larvae is 92.2%.The experimentation on stomach tox- icity was conducted by leaf-sandwich and mouthparts infusion.In 72h,the median lethal concentration (LC₅₀)of the larvae treated by leaf-sandwich is 3.82×10³ mg·L^-1 and the correct mortality of the larvae treated with 5.00×10⁴μg/larvae is 91.2%.LD₅₀ of the larvae treated with mouthparts infusion is 3.80 μg/larvae and the correct mortality of the larvae treated with 1.00×10² μg/larvae is 96.8%.The toxicity of the extract mentioned above showed well contact toxicity and some stomach toxicity.更多还原