2012年盛夏多台风发生对褐飞虱迁飞动态的影响

【目的】台风能极大地改变褐飞虱Nilaparvata lugens(Sta1)的迁飞路径和落区分布,阐释连续登陆的台风对褐飞虱种群动态的影响,可为其异地预测提供科学依据。【方法】通过对2012年盛夏的台风"韦森特"、"苏拉"、"海葵"等影响时期的多站点灯诱数据和风场做轨迹分析,解析台风影响下褐飞虱迁飞动态的变化。【结果】2012年盛夏,多个台风在华南江南早稻黄熟收割和褐飞虱羽化迁出高峰期连续登陆我国,高空气流场和雨带分布发生了不利于褐飞虱北迁的变化。华南地区多盛行东北风或偏东风,即使在台风过境后有利北迁的风向影响时,持续强降水、风切变和下沉气流多发而不利北迁。西南季风受台风影响始终无法主导大气流场,北迁通道难以建立,而褐飞虱的第5次北迁进程受阻。【结论】2012年盛夏台风多发严重阻滞了褐飞虱的第5次北迁过程,大大减轻了长江中下游水稻主产区褐飞虱的危害程度。7月中下旬和8月上旬的风场条件和雨带位置是决定我国长江中下游稻区褐飞虱发生程度的重要预警指标。

The effect of typhoons on the migration patterns of the brown planthopper in the summer of 2012

Objectives] To understand the effects of successive typhoons on the migration dynamics of the brown planthopper in order to provide useful information for inter-regional forecasting. Methods] The influence of successive typhoons （1208 Vicente, 1209 Saola and 1211 Haikui） in the summer of 2012 on the migration patterns of brown planthopper （BPH） Nilaparvata lugens （Sthl） were studied by trajectory analysis based on light-trap data and NCEP-NCAR reanalysis of data with GRADS and HYSPLIT. Results] The synoptic wind fields and rain belt in eastern China became unfavorable to the northward migration of BPH when typhoons were approaching and had made landfall. The northward migration passage of the hoppers was broken by the prevailing northeasterly or easterly winds during the typhoons＇ passage, and the fifth northward migration of BPH was obstructed by the continuous strong rainfall, windshear and sinking vertical airflow, even though southerly winds were temporarily re-established after the typhoon had passed. Conelusion] The fifth northward migration process of BPH in 2012 was retarded by unusual typhoon weather. This mitigated the expected serious damage to rice crops in the mid and lower Yangtze River basin. The wind fields and rain belt distribution in eastern China during July and early August will probably be a useful index for forecasting BPH damage in the mid and lower Yangtze River basin.