东亚小花蝽对草地贪夜蛾幼虫的捕食效应

Predatory effect of Orius sauteri on Spodoptera frugiperda larvae

为探明东亚小花蝽Orius sauteri对草地贪夜蛾Spodoptera frugiperda幼虫的控制潜力,开展了不同温度下东亚小花蝽对不同龄期和密度的草地贪夜蛾幼虫的捕食功能反应与干扰作用研究。结果表明:当东亚小花蝽捕食1龄或2龄草地贪夜蛾幼虫时,其捕食功能反应与HollingⅡ模型拟合度较好。东亚小花蝽对草地贪夜蛾1龄幼虫在20℃、25℃和28℃下的瞬时攻击率分别为0.772 4、1.090 0、0.673 6,处理单头幼虫的时间为0.174 9、0.173 7、0.295 5 d,对2龄幼虫,在20℃、25℃和28℃下的瞬时攻击率分别为0.794 5、1.153 8、0.392 2,处理单头幼虫的时间为0.218 9、0.805 6、0.696 0 d;东亚小花蝽对草地贪夜蛾幼虫的捕食量表现出随着猎物密度增加而上升,随自身密度的增加而下降的趋势;同一温度下,东亚小花蝽对1龄幼虫的日均捕食量和寻找效应均高于2龄幼虫,寻找效应与猎物密度成反比;东亚小花蝽对3龄和4龄草地贪夜蛾幼虫的日均捕食量为0;田间自然状态下东亚小花蝽对草地贪夜蛾幼虫的控制率为34.62%。

In order to investigate the control effect of Orius sauteri on Spodoptera frugiperda larvae,the function response and mutual interference were studied with different instar S.frugiperda larvae at different density and temperatures.The results showed that for 1st and 2nd instar larvae,the functional response of O.sauteri could be described with HollingⅡtype equation.The instantaneous attacking rate of O.sauteri on 1st instar larvae were 0.772 4,1.090 0 and 0.673 6 at 20,25 and 28℃,respectively,while the handing time were 0.174 9,0.173 7,0.295 5 d to single S.frugiperda larva.The instantaneous attacking rate changed to 0.794 5,1.153 8,0.392 2 at 20,25 and 28℃when the larvae were in 2nd instar,and the handing time were 0.218 9,0.805 6,0.696 0 d.Predation capacity of O.sauteri increased with the increase of prey density,while declined with the increase of predators.At the same temperature,the predation quantity of and searching efficiency to 1st instar larvae were higher than those of 2nd instar larvae.Furthermore,the searching efficiency was inversely proportional to larva density.The O.sauteri had little predation effect on 3rd and 4th instar larvae.The control rate of O.sauteri on S.frugiperda was 34.62%in the natural state of the field.