南方水稻黑条矮缩病毒病暴发的触发机制：白背飞虱空中廊道的连通性

水稻是白背飞虱的唯一寄主植物，白背飞虱是南方水稻黑条矮缩病毒(SRBSDV)唯一的介体昆虫。冬季中国大陆东部和越南中北部无水稻种植使越冬飞虱的食物链断裂而成生态陷阱，故飞虱和病毒只能在有水稻生长的越南中南三省和我国海南省才能存续循环。我们提出如下假说：SRBSDV的存续取决于空中廊道的连通性；连通性决定了华南携毒回迁的飞虱能否到达越南中南三省及初春这里的迁出飞虱能否直达华南和越南中北部而成春季飞虱种群重建的虫源；海南到越南中部的空中廊道的连通性决定了海南携毒虫源能否进入越南中北部触发SRBSDV的暴发流行。为此，我们将应用大气中尺度模拟、迁飞轨迹分析、空中飞行虫群的高空灯监测、虫源毒源野外调查等研究手段，分析影响稻飞虱空中廊道连通性的天气学背景和动力学机制及其对空中虫群落点分布的影响，阐明中越之间白背飞虱迁飞格局的年际动态及其形成因子，从而揭示SRBSDV暴发流行的触发机制并提取预警指标.

White-backed planthopper (Sogatella furcifera (Horváth), WBPH) only feed on rice, and southern rice black-streaked dwarf virus (SRBSDV) is only transmitted by WBPH. In winter, no rice is growing in China, northern and north central Vietnam, that will make the overwintering WBPH and SRBSDV be trapped into this huge ecological “Death Valley”. So, they can only survive in the areas where there is growing rice in winter, i.e. the southern Hainan and south central Vietnam. The hypotheses: 1. the survival of wintering SPBSDV will depend on the connectivity of aerial corridors of WBPH between China and Vietnam; 2. the connectivity of aerial corridors of WBPH will let the hoppers arrive in south central Vietnam in late autumn and immigrate into southern China and north central Vietnam in Spring to re-colonize the new planting rice fields; 3. the connectivity of the Hainan-north central Vietnam corridor will support the viruliferous WBPH from Hainan to immigrate into north central Vietnam by easterly during March and April or to land on north central Vietnam with summer Typhoon during June and July, which would finally trigger the SRBSDV outbreak and epidemic. Therefore, we will integrate multi-disciplinary research techniques, including mesoscale numerical simulation of atmosphere, trajectory analysis, search-light trap for en route flyers and field survey for WBPH and SRBSDV disease, to analyze the influence of synoptic weather systems and weather processes on the connectivity of aerial corridor of WBPH and the distribution of the immigration areas, and to interpret the annual fluctuation of the migration patterns of WBPH. Then, we will try to reveal the trigger mechanisms and the forecasting indexes for SRBSDV outbreaks and epidemics both in China and Vietnam.