Source in serious outbreak areas of the second generation of Mythimna separata in Northwest China in 2021
The identification of migration paths of the first generation of Mythimna separata and the source relationships between different occurrence areas are crucial for the effective control of the second generation of M.separata larvae.In this study,we collected spatiotemporal dynamics data of M.separata populations from multiple regions in Northwest China during 2021,a typical year with a high incidence of M.separata.We used FNL data to draw wind field maps,simulated migration trajectories using a trajectory model based on the WRF model,and visualized the trajectories using R 4.0.2.Insect monitoring results showed that the peak period of the first generation of M.separata's migration in 2021 was mainly concentrated in early to mid June,with a multi-peak phenomenon in the peak period observed in western China.The peak date of the moths was postponed with the increase of latitude.Wind field analysis showed that during the northward migration of the first generation of M.separata,the Northeast cyclone,Mongolia cyclone,and East Asian cyclone alternately influenced the regions of North China,Northeast China,and Northwest China.The southerly airflow suitable for long-distance migration of M.separata appeared intermittently.One-time long-distance migration was challenging due to frontal weather hindering the northward migration of M.separata,causing them to gather and land.The trajectory analysis showed that after emergence of the first generation of M.separata in the Huanghuai and Jianghuai regions,some remained in the local area,while the majority migrated to North,Northeast,and Northwest China.Insect source exchange occurred between the eastern and western regions.The main sources of M.separata in severe outbreak areas in Northwest China,such as Ningxia,Shaanxi,and Inner Mongolia,originated from Shanxi,Shaanxi,southern Gansu,northern Sichuan and Chongqing.The results of this study can provide new insights for monitoring and controlling M.separata in the new era.
NETL
NSTL
万方数据
