室内测定6种化学杀虫剂对草地贪夜蛾幼虫的毒力

2019年草地贪夜蛾Spodoptera frugiperda入侵我国多个省份和地区,对我国农业生产造成重大影响。化学防治是应对入侵害虫的主要措施,因此,本研究测定了6种不同作用机制杀虫剂对草地贪夜蛾初孵和3龄幼虫的生物活性。结果表明,对初孵幼虫具有较高毒力作用的为氯虫苯甲酰胺、多杀菌素、茚虫威、阿维菌素和甲氧虫酰肼;对3龄幼虫具有较高毒力作用的为氯虫苯甲酰胺、多杀菌素和茚虫威;与初孵幼虫相比,阿维菌素、茚虫威、多杀菌素和甲氧虫酰肼的LC 50分别提高了78.06、1.70、11.73和23.09倍。本研究筛选出了对草地贪夜蛾初孵幼虫和3龄幼虫杀虫效果较好的药剂,证明了低龄幼虫对部分农药抵抗力较弱,而3龄后的幼虫抵抗力显著增加,为田间草地贪夜蛾的化学防治提供了科学的用药指导。

Laboratory toxicity test of 6 chemical insecticides against Spodoptera frugiperda

In 2019, Spodoptera frugiperda invaded many provinces and regions in China, which had a significant impact on agricultural production. Chemical control is the primary measure to manage invasive pests. Therefore, the bioactivities of six pesticides with different action mechanisms against the newly hatching and third instar larvae of S. frugiperda were determined in this study. The results showed that chlorantraniliprole, spinosad, indoxacarb, abamectin and methoxyfenozide had higher toxicity to newly hatched larvae; chlorantraniliprole, spinosad and indoxacarb had higher toxicity to the third instar larvae; and compared with the newly hatched larvae, the LC50 of the third instar larvae increased 78.06, 1.70, 11.73 and 23.09 times, respectively. In this study, we screened out the insecticides with high insecticidal effect on the first hatching and third instar larvae of S. frugiperda, respectively; proved that the resistance of the younger larvae to some pesticides was weak, but the resistance of the larvae after the third instar increased significantly; and provided scientific medication guidance for the chemical control of S. frugiperda in the field.