Source areas and landing mechanisms of early immigrating white-backedlanthoppers Sogatella furcifera (Horváth) in southeastern Yunnan
Author of the article:XU Lan-Zhen1** CHEN Ai-Dong2 ZHAO Xue-Qing2 ZHAI Bao-Ping1***
Author's Workplace：1. Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; 2. Institute of Agricultural Environments and Resources, Yunnan Academy of Agricultural Sciences, Kunming 650205, China
Key Words：white-black planthopper, early immigration, Vietnam, source areas, landing mechanisms
Abstract：[Objectives] The complicated terrain of southeastern Yunnan is an important pathway for the spring migration of the white-backed planthopper (WBPH), Sogatella furcifera (Horváth). Determining the source area and factors that induce the mass landing of early migrant WBPH is important for forecasting outbreaks of this pest. [Methods] (1) The origins of WBPH captured in light-traps in Funing, Malipo, Guangnan and Qiubei, during each peak period of abundance in April and May from 2008 to 2012 were tracked by trajectory analysis with HYSPLIT. (2) Detailed GrADS analysis of NCEP grid data during periods of peak light trap catch abundance was used to reveal the atmospheric conditions during WBPH immigration and the climatic factors associated with mass landing. [Results] (1) Northern Vietnam and northern Laos are the major source areas of immigrating WBPH in southeastern Yunnan, but some early immigrants in April generally come from mid-north Myanmar and the Shan plateau, northern Thailand (Golden Triangle) and southwestern Yunnan. (2) Wind shear, low temperature, precipitation and downdrafts are the principal factors that induce the large scale mass landing of WBPH, accounting for 75.9%, 56.5%, 31.8 and 25.2% of immigration events, respectively.[Conclusion] The source areas of WBPH immigrants during April and May in southeastern Yunnan are generally in the Indo-Chinese Peninsula. Synergy between wind shear, low temperature, heavy rainfall and downdrafts plays a critical role in immigration events.