益蝽不同龄期若虫对草地贪夜蛾幼虫的捕食能力

为了评估益蝽若虫对草地贪夜蛾不同龄期幼虫的捕食潜力，本试验在室内条件下开展了益蝽若虫对草地贪夜蛾3、4、5龄幼虫的捕食能力试验。结果表明：益蝽3、4、5龄若虫对草地贪夜蛾3、4、5龄幼虫的捕食功能反应均符合HollingⅡ圆盘方程，3龄若虫对草地贪夜蛾3、4、5龄幼虫的日最大捕食量分别为55.556、8.019、5.666头；瞬时攻击率分别为0.819、1.826、1.503；处理时间分别为0.018、0.125、0.177 d。4龄若虫对草地贪夜蛾3、4、5龄幼虫的日最大捕食量分别为60.753、19.924、10.325头；瞬时攻击率分别为0.993、1.664、0.968；处理时间分别为0.017、0.050、0.097 d。5龄若虫对草地贪夜蛾3、4、5龄幼虫的日最大捕食量分别为65.789、23.635、12.331头；瞬时攻击率分别为1.021、1.307、0.863；处理时间分别为0.015、0.042、0.081 d。益蝽若虫对草地贪夜蛾3、4、5龄幼虫都能捕食，对3龄幼虫捕食量最大，最喜欢捕食4~5龄幼虫，对4龄幼虫的瞬时攻击率最高。益蝽若虫对草地贪夜蛾具有较好的捕食能力，本文为草地贪夜蛾的可持续防控提供了新的方法和依据。

Predation of Picromerus lewisi Nymph on Larvae of Spodoptera frugiperda

The predation potential of Picromerus lewisi (Fallou) to Spodoptera frugiperda (J. E. Smith) was evaluated using P. lewisi nymph and 3^rd, 4^th and 5^th instar larvae of S. frugiperda under indoor conditions. The results showed that the maximum daily predation amount of P. lewisi 3^rd nymph to the 3^rd, 4^th and 5^th instar larvae of S. frugiperda was 55.556, 8.019 and 5.666, respectively. The instantaneous attacking rates were 0.819, 1.826 and 1.503, respectively. The handling time was 0.018, 0.125 and 0.177 day, respectively. The maximum daily predation amount of P. lewisi 4^th nymph to the 3^rd, 4^th and 5^th instar larvae of S. frugiperda was 60.753, 19.924 and 10.325, respectively. The instantaneous attacking rates were 0.993, 1.664 and 0.968, respectively. The handling time was 0.017, 0.050 and 0.968, respectively. The maximum daily predation amount of P. lewisi 5^th nymph to the 3^rd, 4^th and 5^th instar larva of S. frugiperda was 65.789, 23.635 and 12.331, respectively. The instantaneous attacking rates were 1.021, 1.307 and 0.863, respectively. The handling time was 0.015, 0.042 and 0.081, respectively. P. lewisi 3^rd-5^th nymph can prey on 3^rd, 4^th and 5^th instar larvae of S. frugiperda, with predation amount to the 3^rd instars the largest, preference more for the 4^th and 5^th instars, and attacking efficiency to the 4^th instars the highest. The results indicate that P. lewisi has good control effect on S. frugiperda and can be used for the prevention and control of this pest.