核型多角体病毒对玉米草地贪夜蛾的控制作用研究

草地贪夜蛾Spodoptera frugiperda是严重威胁我国玉米生产的入侵害虫。为科学、有效地防控草地贪夜蛾,本文应用浸卵法和浸叶法,在室内研究了几种核型多角体病毒Nucleopolyhedrovirus(NPV)对草地贪夜蛾的毒力,并利用喷雾法进行了田间控制作用研究。结果表明,几种核型多角体病毒浸卵处理10 s对草地贪夜蛾的卵孵化率无明显影响,但苜蓿银纹夜蛾NPV浸卵对草地贪夜蛾卵孵化有一定的延迟作用,24、48 h的孵化率分别为12.50%、69.17%,显著低于对照;核型多角体病毒浸卵对初孵幼虫的毒力较强,棉铃虫NPV、甜菜夜蛾NPV浸卵后初孵幼虫死亡率最高,分别达92.32%、82.49%;草地贪夜蛾3龄幼虫取食浸过核棉铃虫NPV、甜菜夜蛾NPV的玉米叶片72 h后,其死亡率分别为96.39%、92.82%,甘蓝夜蛾NPV对3龄幼虫也具有较强毒杀作用。同时核型多角体病毒对草地贪夜蛾幼虫发育有一定抑制作用,3龄幼虫取食经棉铃虫NPV、甜菜夜蛾NPV处理的叶片72 h平均虫龄分别为3.00龄和3.36龄,显著低于对照。玉米田喷施甜菜夜蛾NPV、甘蓝夜蛾NPV,药后10 d对草地贪夜蛾的防效分别达到86.03%和82.36%。研究表明,甜菜夜蛾NPV、甘蓝夜蛾NPV杀虫剂对玉米草地贪夜蛾具有较好的防控效果,可以作为其有效防控的生物农药。

Study on the control effect of Nucleopolyhedrovirus on Spodoptera frugiperda

Spodoptera frugiperda is a pest that seriously threatens the safety of corn production in China. For the scientific and effective prevention and control of S. frugiperda, the toxicity of several Nucleopolyhedrovirus (NPV) on S. frugiperda was studied in laboratory using egg immersion and leaf dipping methods. Field control effects were carried out using the spray method. The results showed that the immersion with other Nucleopolyhedrovirus for 10 s had no significant effect on the hatching rate of S. frugiperda eggs, but the immersion with AcMNPV delayed the hatching of S. frugiperda eggs, and the hatching rate of 24 h and 48 h were 12.50% and 6917%, respectively, which were significantly lower than that of the control. The immersion of eggs with NPVs showed high toxicity to the newly hatched larvae, and mortalities caused by the HaNPV and SeNPV were 92.32% and 82.49%, respectively. When the 3rd instar were fed with corn leaves dipped in HaNPV and SeNPV, the mortalities 72 h post treatment were 96.39% and 92.82%, respectively. The MbNPV also had a strong toxicity to the 3rd instar larvae. At the same time, the NPVs inhibited the development of the larvae of S. frugiperda, the average age of the newly hatched larvae was 3.00 instar and 3.36 instar 72 h post treatment with the HaNPV and SeNPV, which were significantly lower than that of the control. The spray of SeNPV and MbNPV in corn field showed high control effect to S. frugiperda, which were 86.03% and 82.36% 10 day post treatment. The results of this study showed that the SeNPV and MbNPV has good control effect against the S. frugiperda, and can be used as a biological pesticide for effective prevention and control of S. frugiperda.