蓖麻叶片提取物对斜纹夜蛾幼虫的影响

目的]了解不同生育期蓖麻叶片乙醇提取物对斜纹夜蛾的影响,为蔬菜斜纹夜蛾的生物防治提供参考.方法]研究了3个生育期（初果期、盛果期、成熟前期）蓖麻叶片提取物对斜纹夜蛾幼虫的嗅觉反应、取食行为和幼虫成活率的影响.结果]提取物对斜纹夜蛾幼虫2龄和5龄幼虫的驱避率均在69％以上;和对照相比,幼虫对处理包菜的取食量下降了42.46％ ～47.08％,取食活动次数和取食时间减少,幼虫的成活率下降了38.10％ ～52.39％.3个生育期的提取物对斜纹夜蛾幼虫的驱避作用强弱顺序依次为成熟前期、盛果期、初果期,但在斜纹夜蛾幼虫的取食量、成活率上没有明显差异.结论]蓖麻叶片对斜纹夜蛾具有一定的驱避作用和抗生作用.

Effects of Extracts from Castor Plant Leaves against Spodoptera litura Fabricius Larva

Objective] The aim was to understand effects of extracts from castor plant leaves against Spodoptera litura Fabricius larva to provide reference for bio-control of Spodoptera litura.Method] The olfactory response of extracts from castor leaves at early fruit-setting stage,full fruit-setting stage and fruit pre-mature stage on Spodoptera litura were studied,and effects of the extracts on the feeding behavior of S.litura larvae and larval survival rate were also studied.Result] The extracts from castor bean leaves had significant repellent effects on S.litura.The repellent rates of both 2nd and 5th larvae exceeded 69％.Compared with the control,larvae treated cabbage food intake decreased by 42.46％-47.08％,the number of feeding activity and feeding time was reduced,and the survival rate of larvae was decreased by 38.10％ -52.39％.The repellent intension of the extracts of the three growth stages to S.litura were pre-mature period ＞ full fruiting period ＞ early fruit-setting period.But,there was no significant difference between S.litura larvae＇s food consumption and the survival rate.Conclusion] The castor bean leaves have good repellent and antibiosis effects on S.litura.