七星瓢虫对草地贪夜蛾低龄幼虫的捕食能力评价

Predation of Coccinella septempunctata on Young Larvae of Spodoptera frugiperda

为了评估七星瓢虫Coccinella septempunctata对重大入侵害虫草地贪夜蛾Spodoptera frugiperda(J. E.Smith)的防控效果,本试验在室内条件下开展了七星瓢虫对草地贪夜蛾1龄、2龄幼虫的捕食功能反应和种内干扰研究。结果表明:七星瓢虫对草地贪夜蛾幼虫的捕食功能反应均符合HollingⅡ模型,七星瓢虫对草地贪夜蛾1龄幼虫的日最大捕食量、瞬时攻击率和处理时间分别为233.100头、1.204和0.103h;对草地贪夜蛾2龄幼虫的日最大捕食量、瞬时攻击率和处理时间分别为41.220头、1.075和0.582 h。七星瓢虫的搜寻效应随猎物密度的增加而逐渐降低。七星瓢虫对草地贪夜蛾的捕食作用受到较强的种内干扰。试验证明七星瓢虫对草地贪夜蛾具有较好的控害效果,可用于对草地贪夜蛾的防控实践。

To evaluate the control potential of Coccinella septempunctata adults on the 1st instar and 2nd instar larvae of Spodoptera frugiperda(J.E.Smith),the functional responses and mutual interference of C.septempunctata were studied in laboratory.The results showed that the maximum daily predation amount,the sequence of attacking efficiency and the handling time C.septempunctata adults on the 1st instars of S.frugiperda were 233.1,1.204 and 0.103 h,respectively;and the values on the 2nd instars of S.frugiperda were 41.2,1.075 and 0.582 h,respectively.The C.septempunctata adults gradually reduced their search activities as the density of prey increases.The predation of C.septempunctata was strongly affected by intraspecific interference.This study proves that C.septempunctata adults are efficient for the control of S.frugiperda and can be used in biological control of S.frugiperda in field.