BACKGROUND: Since the invasion of fall armyworm (FAW) into Asia, it has posed a threat to agricultural production across Asian countries. The southwestern border region of China serves as a key pathway for FAW migration from the Indo-China Peninsula into China. Understanding the transboundary migration dynamics of this pest facilitates source control and early prevention and control measures. RESULTS: Systematic monitoring for transboundary migration dynamics of FAW was conducted during 2019-2024 in Jiangcheng County of Yunnan province located at the border area between Southwestern China and the Indo-China Peninsula. The results indicate typical northward migration of FAW during spring, summer, and autumn, while winter was characterized by local dispersal population. Northward migratory FAW populations primarily originated from Myanmar, Laos, Vietnam, and Thailand (immigrant FAW population sources accounted for 93.56% in spring, 89.35% in summer, and 82.93% in autumn, 98.89% in winter). In terms of distribution in the migration destination areas, the landing points were predominantly located in Yunnan Province, Guangxi Province, and Guizhou Province in China (97.18% in spring, 89.89% in summer, 89.22% in autumn, and 93.89% in winter). CONCLUSION: FAW populations in the Indo-China Peninsula undergo continuous cross-border northward migration into China through south Yunnan during spring, summer, and autumn, with no backward migration observed in all seasons. These findings provide a scientific basis for establishing precise monitoring and regional integrated management for FAW. © 2026 Society of Chemical Industry.
Zhao et al. (Sun,) studied this question.