云南师宗白背飞虱前期迁入种群的虫源地分布与降落机制

Source areas and landing mechanisms of early immigrant population of whitebacked planthoppers Sogatella furcifera( Horváth) in Shizong,Yunnan Province

通过对1990—2012年云南省师宗县4—5月出现的白背飞虱灯诱高峰日进行轨迹模拟以及降虫高峰日的风场分析,得到以下结果:4月下旬,师宗上空盛行西风,白背飞虱虫源主要来自缅甸东北部,部分来自越南北部和金三角地区;5月份,西南风为盛行风向,其中上中旬的虫源地主要分布在越南西北部、老挝北部和滇西南,缅甸东北部可提供部分虫源;下旬则主要分布在滇西南,部分虫源来自越南西北部、老挝北部和缅甸东北部。对降虫高峰期的大气环流背景、峰日风温场、降雨等气象因子的分析结果表明,降水、风切变和气流垂直扰动是造成白背飞虱集中降落的主要因子。

From April to May, 1990 -2012, the source areas of early immigration of white-backed planthoppers Sogatella furcifera （Horvrth） （WBPH） were studied through the analysis on the daily light-trap catches, immigration trajectory simulation and horizontal wind field. The following results were obtained： The high frequency of westerly wind carried the large population of WBPH to Shizong in late April. The source areas were mainly located in northeastern Myanmar and the secondary source areas were at northern Vietnam and Golden Triangle. Airborne WBPH populations were carried by a strong, low-level, southwest jet-stream in May and the mass immigration of WBPH into Shizong during early and middle May was found form northern Laos, northwestern Vietnam and Southwestern Yunnan, and some immigrants from northeastern Myanmar. Most of the immigrants in late May were tracked to Southwestern Yunnan, and part of immigrants to northwestern Vietnam, northern Laos and rainfall distribution, it was found and northeastern Myanmar. Based on the analysis on the meteorological background that the extensive heavy rainfall in southeastern Yunnan during late April to May and low temperature shield of surrounding to flying WBPH and the wind shear associated with heavy precipitation were the key factors to affect the concentrated landing of WBPH.