东北二代粘虫大发生机制：1978年个例分析
Outbreak mechanism of second generation armyworms innortheastern China: A case study in 1978
胡 高1 吴秋琳1 武向文1 姜玉英2 曾 娟2 翟保平1**
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DOI：
作者单位：1. 南京农业大学昆虫学系 农作物生物灾害综合治理教育部和农业部重点实验室，南京 210095；2. 全国农业技术推广服务中心，北京 100125
中文关键词：粘虫暴发，东北，西南大风，强降水
英文关键词：outbreak of armyworm, northeasternChina, strong southwesterly, heavy rainfall
中文摘要：
【目的】 迁入我国东北地区的粘虫繁殖一代后，新羽化的成虫将外迁他地，但某些年份因某种特殊的天气过程而滞留当地，形成当地的2代种群并造成严重危害，如1978年。阐明种群滞留的关键因子和大发生种群的形成机制，是实现东北2代粘虫准确预测和及时防治的前提。【方法】 根据东北三省的虫情资料，利用NCEP/NCAR再分析资料和WRF模式输出的大气背景场，对1978年东北地区粘虫蛾盛期的种群动态和迁飞过程进行逐日分析。【结果】 （1）因副热带高压稳定偏北导致发蛾峰期东北地区盛行西南风，东北2代粘虫蛾无法向南回迁至关内华北地区，而是向北迁飞；（2）当年黑龙江2代粘虫大发生，其虫源是由当地1代羽化后在当地的存留或迁出成虫蛾又折返黑龙江以及辽宁与吉林两省2代成虫的迁入造成；（3）蛾峰期黑龙江上空气旋的频繁活动、强对流天气的持续出现以及丰富的降水是造成当地虫源滞留和迁入虫源降落与滞留的原因。【结论】 东北1代粘虫蛾迁出期的西南大风和大范围强降水使大量迁出种群和过境种群集中滞留在三江平原而形成大发生种群，造成东北2代粘虫1978年在黑龙江的暴发。
英文摘要：[Objectives] In some years newly emerged moths of the 1st generation armyworm, Mythimna seperata (Walker), in northeastern China fail to emigrate successfully because of adverse weather conditions and consequently remain in their birthplace to form 2nd generation populations that inflict serious damage on summer crops. Better understanding of the outbreak mechanism of such summer populations is important to improve our ability to forecast and manage these outbreaks. [Methods] A case study of an armyworm outbreak inHeilongjiangProvincein 1978 was performed using trajectory analysis of NCAR/NCEP reanalysis data using the WRF system. [Results] (1) Southwesterly winds were predominant in northeasternChinaas a subtropical high in the western Pacific remained stable further north than usual in July. M. seperata emigrating during these periods moved northward rather than southward, thus moths could not return to their summer habitats in northern China; (2) The swarm of moths that settled in Heilongjiang Province were a mixture of the local population formed by unsuccessful emigrants and immigrants from Jilin and Liaoning Provinces, and these moths produced the outbreak in Heilongjiang Province in 1978; and (3) Frequently passing cyclones, strong convective weather patterns and heavy rainfall acted as key factors to suppress the emigration of local moths and force large scale immigration into Heilongjiang Province. [Conclusion] The armyworm outbreak inHeilongjiangProvincein 1978 was caused by the retarded local emigrants of the 1st generation armyworm as a result of adverse weather and the forced landing airborne moths transported northwardly by strong southwesterly winds and then concentrated and swept to the Sanjiang Plain by large scale heavy rainfall.