2019年海南省草地贪夜蛾迁入路径及虫源分析初探

Preliminary study of the migration path and source areas of the fall armyworm Spodoptera frugiperda in Hainan province in 2019

【目的】明确草地贪夜蛾Spodoptera frugiperda迁入海南省的虫源地和迁入路径,旨在为海南省草地贪夜蛾的预测预报提供科学依据。【方法】基于2019年海口市草地贪夜蛾虫情数据,采用WRF模式中昆虫三维轨迹分析程序,结合草地贪夜蛾的飞行行为参数和气象数据,模拟了海南草地贪夜蛾的迁飞路径,并分析了气象背景场。【结果】2019年,草地贪夜蛾进入海南的迁飞时间集中在4月15-20日左右;此时间段,越南的西南风及华南对流层底层的急流为草地贪夜蛾的迁飞提供了携带气流,强对流引发了降雨和风向切变,高空的空气冷却后向下运动,为草地贪夜蛾的下降提供了有利条件;草地贪夜蛾在4月15-17日具备有效的迁飞路径,海南省海口市的入侵虫源主要来自越南和广东北部,副热带高压系统、降水和风的模式促使了草地贪夜蛾进入海南。【结论】本研究初步明确了2019年草地贪夜蛾入侵海南的最早时间及虫源分布,为海南省草地夜蛾的监测、预警及综合防控提供了理论参考。

[Objectives]To clarify the source population and migration pattern of Spodoptera frugiperda migrating into Hainan province,and provide a scientific basis for predicting the presence of S.frugiperda in Hainan.[Methods]Using data on S.frugiperda collected in Haikou city in 2019,the WRF three-dimensional,trajectory-analysis program,combined with the flight behavior parameters S.frugiperda and relevant meteorological data,were used to analyze the migratory path of this species in Hainan.Weather parameters during the migration were also simulated and analyzed.[Results]S.frugiperda migrated into Hainan in 2019 mainly from the 15th to the 20th April.During this period,southwesterly winds in Vietnam and a low-level jet-stream in southern China provided the carrier airflow for the migration,whereas strong convection rainfall,wind shear and downdraft forced the landing of migrating insects.There was an effective flight path of S.frugiperda from the 15th to the 17th of April,which allowed it to invade Haikou city,Hainan province.The source population was in Vietnam and northern Guangdong.Subtropical high pressure,precipitation and wind patterns led to the migration of this population to Hainan.[Conclusion]This preliminarily study has clarified the earliest migration of S.frugiperda in southern Hainan in 2019 and the source population for this migration.