大草蛉幼虫对草地贪夜蛾低龄幼虫的捕食能力评价

为明确大草蛉对草地贪夜蛾的控害潜能，本试验在室内评价了大草蛉幼虫对草地贪夜蛾低龄幼虫的捕食及搜寻能力，并观察总结了大草蛉的捕食行为特点。结果表明：大草蛉2龄、3龄幼虫对草地贪夜蛾1龄、2龄幼虫均表现出积极的取食行为和较强的捕食能力，尤其对草地贪夜蛾1龄幼虫的日均捕食量较大，分别为78.5头、89.9头，理论条件下日最大捕食量可达125头、167头，其捕食功能反应均符合Holling Ⅱ模型。大草蛉3龄幼虫对草地贪夜蛾低龄幼虫的捕食量、搜寻能力及控害效能均显著高于2龄幼虫，对猎物的瞬时攻击率更强，处理时间更短。本研究结果证实大草蛉幼虫对草地贪夜蛾低龄幼虫均具有较强的控害能力，这对利用草蛉类天敌持续防治草地贪夜蛾具有重要的实践指导意义。

Predation Capacity of Chrysopa pallens Larvae to Young Larvae of Spodoptera frugiperda

The potential of Chrysopa pallens (Rambur) to control Spodoptera frugiperda (J.E.Smith) was evaluated under laboratory conditions in this study, and the predation behavior was also observed. The results indicate that the 2^nd and 3^rd instar larvae of C. pallens showed active feeding behaviors and strong predatory ability against the 1^st and 2^nd instar larvae of S. frugiperda. In particular, both the 2^nd and 3^rd instar larvae of C. pallens had a large predatory capacity to the 1^st instar larvae of S. frugiperda, with the average daily predation amount of 78.5 and 89.9, respectively, which corresponds to the maximum daily predation amount of 125 and 167, respectively, under theoretical conditions. All stages of C. pallens showed a type II functional response. The predation capacity, searching ability and controlling efficacy of C. pallens 3^rd instar larvae to S. frugiperda young larvae were significantly higher than those of C. pallens 2^nd instar larvae, respectively. And, the 3^rd instar larvae of C. pallens had much higher attacking rate, but shorter handling time. This study confirms that C. pallens larvae have a strong ability to control the young larvae of S. frugiperda, which has an important practical meaning for the long-term sustainable control of S. frugiperda by the predatory insect lacewings.