八宝景天乙醇提取物对菜青虫的生物活性

Bioactivity of Sedum spectabile Boreau Extracts against Pieris rapae

[目的]室内测定了八宝景天乙醇提取物对菜青虫3龄幼虫的拒食和触杀作用。[方法]采用小叶碟法和浸渍法分别测定乙醇提取物对菜青虫的拒食和触杀作用。[结果]浸渍法处理对菜青虫3龄幼虫48、72 h的致死中浓度(LC50)分别为7.768、0.183 g/L,且校正死亡率均达100%,24、48 h的拒食率最高分别为99.15%、91.94%,拒食中浓度(AFC50)分别为4.819、15.442 g/L。[结论]八宝景天乙醇提取物对菜青虫3龄幼虫具有较高的拒食和触杀活性,为生物源农药提供了一种新的植物来源。

[Aims] The antifeeding and contacting activities of the ethanol extracts from Sedum spectabile Boreau against 3rd instar larvae of Pieris rapae were determined in laboratory. [Methods] The leaflets disc method and immersion method were adopted respectively to test the antifeeding and contacting activities of the ethanol extracts against P. rapae. [Results] The LCs0 were %768 and 0.183 g/L respectively at 48 and 72 h by dipping method, and the adjusted mortality were both 100%. The highest antifeeding rate were 99.15 and 91.94% respectively at 24 and 48 h, and the AFC50 were 4.819 and 15.442 g/L respectively. [Conclusions] Ethanol extracts from S. spectabile Boreau has high contacting and antifeeding effects against 3rd instar larvae of Pieris rapae, which provides a new plant resource for biopesticides.