为了澄清二点委夜蛾主害代发生为害与小麦收获及玉米播种期之间的关系,2012年在小麦收获和玉米播种同期,饲养二点委夜蛾当日所产卵,并播种玉米,定期调查幼虫龄期发育进度和玉米幼苗叶龄生长情况。调查结果显示,小麦收获并秸秆还田后二点委夜蛾1代成虫产下的卵发育而成的幼虫(2代幼虫),是二点委夜蛾为害夏玉米的主要虫源,与田间系统调查结果吻合。小麦收获前,1代成虫产卵不集中,不易造成危害;小麦收获后,高麦茬上覆盖麦秸所造成的有空隙的环境有利于成虫集中栖息并产卵,玉米播种后灌水造墒有利于卵的孵化和低龄幼虫生长发育,是造成危害的主要虫源;玉米播种7 d后成虫产的卵再孵化出的幼虫因虫龄小、玉米叶龄大,不易造成危害。以此为基础,揭示了二点委夜蛾暴发为害夏玉米机制,进一步明确了在小麦收获玉米播种期间处理好田间麦秸,破坏二点委夜蛾适宜集聚的生态环境,是治理该虫为害的关键。小麦收获和玉米播种期间采用农药集中杀灭成虫和低龄幼虫是减少该虫危害的重要防控措施。 In order to clarify the relationship between the damage caused by the main insect pests and the harvest of wheat and the sowing time of maize, the two-month-old Eumex moths were oiled on the same day and sown on the same period The development of larvae and the growth of leaves of corn seedling were investigated. The results showed that the larvae (second generation larvae) developed from the eggs laid by the first generation of the 2nd instar Spodoptera litura after the wheat was harvested and straw was returned were the main source of summer maize damage caused by the second instar larvae, System survey results agree. Before wheat harvest, the first generation of adults lay eggs are not concentrated, not easy to cause harm; wheat harvest, high wheat stubble covered by straw caused by the gap environment is conducive to adult habitat and spawning, corn sowing after planting water is conducive to moisture And the growth and development of young larvae were the main source of the damage. The larvae hatched again after 7 days of maize sowing were not likely to cause harm due to the small insects and large leaf age of maize. Based on this, we revealed the mechanism of summer corn caused by the occurrence of Spodoptera exigua and further clarified the ecological environment suitable for the accumulation of wheat straw during the sowing of wheat harvest and the proper concentration of the two species of Spodoptera exigua. The essential. The use of pesticides to kill adults and young larvae intensively during wheat harvest and maize seeding is an important control measure to reduce the harm of this pest.