3种拟除虫菊酯类农药对草地贪夜蛾的毒力测定及田间应用效果评价

评价使用氟氯氰菊酯、溴氰菊酯、高效氯氟氰菊酯喷雾和喇叭口点施处理对草地贪夜蛾的活性与防效,为草地贪夜蛾综合防控提供技术支持。采用喷雾法测定了3种农药原药对草地贪夜蛾3龄幼虫毒力;采用喷雾和喇叭口点施2种方式田间施用5.7%氟氯氰菊酯乳油、25 g/L溴氰菊酯乳油、5.0%高效氯氟氰菊酯乳油,药后第1天、第3天、第7天调查挂牌标记玉米上草地贪夜蛾活虫数,计算防治效果。3种拟除虫菊酯农药对草地贪夜蛾3龄幼虫LC 50值大小顺序依次为氟氯氰菊酯(29.80 mg/L)<高效氯氟氰菊酯(42.39 mg/L)<溴氰菊酯(49.88 mg/L);3种拟除虫菊酯类农药在54.00 g a.i./ha剂量下均能明显降低草地贪夜蛾田间虫口数量,同等剂量防效氟氯氰菊酯乳油>高效氯氟氰菊酯乳油>溴氰菊酯微乳剂。由于草地贪夜蛾低龄幼虫和高龄幼虫取食部位有差异,喷雾法防治低龄幼虫的效果好,喇叭口点施防治高龄幼虫的效果好。拟除虫菊酯类农药对草地贪夜蛾具有较好的防治效果,喇叭口点施方式节省药剂、提高对高龄幼虫的防效,在防治草地贪夜蛾等害虫方面具有广阔的应用前景。

Toxicity determination of three pyrethroid pesticides against Spodoptera frugiperda and evaluation of field application

To evaluate the toxicities and control effects of cyfluthrin, deltamethrin, lambda cyhalothrin spray and flare opening point treatment on Spodoptera frugiperda and to provide technical support for the comprehensive prevention and control of S. frugiperda. Spraying method was used to determine the virulence of third stage larvae of S. frugiperda; 5.7% cypermethrin EC, 25 g/L deltamethrin EC, 5% lambda cyhalothrin ME were applied in the field by spray and flare opening point treatment, the number of live insect of S. frugiperda of labeled corn was investigated and the control effect was calculated on 1 d, 3 d and 7 d after application. The LC50 values of three pyrethroid pesticides on the third stage larvae of S. frugiperda were in order of cypermethrin (29.80 mg/L) < lambda cyhalothrin (42.39 mg/L) < deltamethrin (49.88 mg/L); the three pyrethroid pesticides could significantly reduce the number of insects in the field of S. frugiperda at the dose of 54.00 g ai/ha, and the same dose of cyfluthrin EC>lambda cypermethrin ME>deltamethrin EC. Due to differences in feeding sites of young larvae and old larvae of S. frugiperda, the spraying method has a good effect on the control of young larvae, and flare opening point application treatment has a good effect on the control of old larvae. Pyrethroid pesticides have good control effect on S. frugiperda, and the method of flare opening point application saves pesticide and improves the control effect on the old larvae. It has broad application prospects in the control of S. frugiperda.