乙基多杀菌素对武汉地区草地贪夜蛾卵和幼虫的室内毒力评价

Laboratory Toxicity of Spinetoram Against Eggs and Larvae of Spodoptera frugiperda in Wuhan

采用浸渍法和浸叶法,在室内测定了不同浓度梯度下乙基多杀菌素对武汉地区草地贪夜蛾卵和不同龄期幼虫的毒杀作用。结果表明,乙基多杀菌素对草地贪夜蛾卵的孵化具有一定的抑制作用,且对初孵幼虫具有较高的杀虫活性,对2~4龄幼虫的致死中浓度(LC_(50))分别为0.025、0.070、0.269 mg·L^(-1)。由此可见,乙基多杀菌素仍可作为草地贪夜蛾应急化学防控的使用药剂,但应抓住3龄前施药的关键窗口期。

The laboratory toxicity of spinetoram at different concentration gradients against the eggs and different instars larvae of Spodoptera frugiperda in Wuhan was evaluated using the soak and foliage application methods.The results showed that spinetoram had certain inhibitory effect on the hatching of the eggs of S.frugiperda,and showed high toxicity against newly hatched larvae.The lethal medium concentration(LC_(50))of spinetoram to 2-4 instars larvae were 0.025,0.070 and 0.269 mg·L^(-1),respectively.In conclusion,spinetoram can still be used as an emergency chemical control insecticide for S.frugiperda,with a focus on the critical window period of application before the 3rd instar stage.