雷公藤非生物碱成分对菜青虫杀虫活性研究

雷公藤 ( Tripterygiun wilfordii Hook)属卫矛科雷公藤属植物 ,又名断肠草、菜虫药 ,在我国主要分布于长江中下游地区 ,为著名的杀虫植物之一 1～ 3]。据资料报道 ,雷公藤主要有效杀虫成分为生物碱类 ,现已分离出 5种有杀虫活性的生物碱 3]。 Beroza等 2 ]还发现 ,分离出 5种生物碱后剩下的非结晶物质对欧洲玉米螟 ( Pyrausta nubilalis)初孵幼虫及蚊虫杀虫活性很好。雷公藤非生物碱成分和生物碱的中毒症状相似 ,但有关非生物碱的杀虫作用方式目前还未见报道。作者采用生物活性追踪与化学分离技术相结合的方法 ,从雷公藤根皮中得到了…

Insecticidal Activities of the Non-alkaloid Extracts fromTripterygium wilfordii against Piers rapae L.

The non-alkaloid contents were extracted from the root bark o f Tripterygium wilfordii Hook. The results of bioassy showed that the non- alkaloid extracts has abviously insectidal activities to imported cabbage worm ( Pieris rapae L.).LC50 values of poisoning to the 5th instarts of Pie ris rapae is 7.23 mg.L-1. The values of medium antifeeding concentratio n (AFC50) of the non-alkaloid extracted against the 5th larval of Pieris rape is 11.34 mg.L-1. Median narcosis dose (ND50) is 15.54 μg/g.Me dian contact dose (LD50) is 3.1079 μg/head. The non-alkaloid extract s have no fumigant to insect. The main poisoning symptoms are that the tested in sect showed paralysis and the epiderm of the larval turns black, the larval are dead at last.