2021年湖南省草地贪夜蛾迁飞路径及虫源地分析

为明确2021年湖南省草地贪夜蛾Spodoptera frugiperda的迁飞路径与虫源地，基于2021年湖南省60个县（市、区）的高空测报灯诱集数据及性诱捕数据，通过HYSPILT分析平台分析其迁飞轨迹及虫源地，同时使用NCL气象软件分析2021年草地贪夜蛾迁飞期间的天气背景，获得草地贪夜蛾在湖南省的迁飞路径。结果表明，2021年3月下旬最早在湘西南（怀化市）发现草地贪夜蛾，4月下旬至5月中旬进入草地贪夜蛾大规模迁入期。草地贪夜蛾主要经西、中、东3条路线迁入湖南省，西线以贵州省为主要虫源地，中线以广西壮族自治区为主要虫源地，东线则以广东省为主要虫源地。草地贪夜蛾迁出路径由湘西南迁向湘东北直至迁飞出省，最远可达江苏省沿海地区。结合迁飞轨迹与水平风场分析发现，由东太平洋以及孟加拉湾的热带及亚热带暖湿气流提供的运载气流是草地贪夜蛾迁飞的重要条件。2021年湖南省草地贪夜蛾的迁飞路径整体表现为由西南向东北，虫源地主要分布在贵州省和广西壮族自治区，小部分分布在广东省。

Analysis of the migration path and source areas of fall armyworm Spodoptera frugiperda in Hunan Province in 2021

To better understand the migration routes and source areas of fall armyworm Spodoptera frugiperda in Hunan Province in 2021, the HYSPILT analysis platform was utilized to simulate the migration trajectory of the species. Additionally, the NCAR Command Language (NCL) was employed to analyze the weather conditions during migration based on the data obtained from vertical-pointing searchlight-traps and sex pheromone traps across 60 counties, cities, and districts in Hunan Province in 2021. The results showed that S. frugiperda initially migrated into southwestern Hunan Province (Huaihua City) in late March 2021, and subsequently, a large scale invasion occurred from late April to mid-May. S. frugiperda utilized three migration pathways to enter Hunan Province: west, middle, and east. The main source areas of insects were identified as Guizhou Province for the western route, Guangxi Zhuang Autonomous Region for the middle route, and Guangdong Province for the eastern route. The overall migration path of S. frugiperda in Hunan proceeded from southwest to northeast, terminating in the coastal areas of Jiangsu Province. Combined with the analysis of migration trajectory and horizontal wind fields, it was found that the carrier airflow facilitated by tropical and subtropical warm and humid airflow from the eastern Pacific Ocean and the Bay of Bengal played a key factor in the successful immigration of S. frugiperda into Hunan. In 2021, the migration path of S. frugiperda in Hunan was predominantly from southwest to northeast, with the major source populations located in Guizhou Province and Guangxi Zhuang Autonomous Region, while a smaller portion originated from Guangdong Province.