广西兴安地区稻纵卷叶螟早期迁入虫源分析

Analysis of the source areas of the early immigration of rice leafroller,Cnaphalocrocis medinalis in Xing'an,Guangxi

运用大气质点轨迹分析平台HYSPLIT 4.8对2007—2011年广西兴安地区早期灯下稻纵卷叶螟Cnaphalocrocis medinalis Guenée主要迁入峰进行了轨迹模拟,并运用气象图形处理软件GrADS对迁飞高峰期进行气象背景分析。结果显示,广西兴安地区稻纵卷叶螟于5月初开始零星迁入,迁入高峰期集中在5月下旬至6月下旬,最大迁入峰集中在6月中下旬。诱虫量及迁入峰次年度间存在差异。广西兴安地区稻纵卷叶螟5月迁入虫源主要来自海南中部、西南部,老挝和泰国北部,广西南部、广东西南部也能提供部分虫源。6月迁入虫源主要集中在广西南部、广东西南部、海南中部、老挝中部稻区,越南中部稻区也能提供部分虫源。稻纵卷叶螟迁入峰期925 hPa等压面上气流方向均为较强的西南或偏南气流。降雨和气流的垂直扰动导致稻纵卷叶螟大规模迁入降落。

The spatiotemporal distribution of source areas of the early migration peaks of rice leafroller,Cnaphalocrocis medinalis Guenée,were analyzed using HYSPLIT 4. 8( Hybrid Single-Particle Lagrangian Integrated Trajectory),a software package that simulates migration trajectories,and GrADS( Grid Analysis and Display System), a program for analyzing and displaying the synoptic meteorology background during the migration periods in 2007—2011. The rice leafroller started immigrating in Xing'an in early May,and the large-scale immigration peaks were between late May and late June,while the biggest immigration peaks were in middle and late June. The pest catches in light traps were different among years. The main source areas of the early immigration of rice leafroller in May were located at the middle and southwestern Hainan,the northern Laos and Thailand,and the secondary source areas were at southern Guangxi and the southwestern Guangdong. The source areas of rice leafroller immigration in June were located at the southern Guangxi,the southwestern Guangdong,the middle of Hainan and Laos,whereas the secondary source area was at the middle of Vietnam. The wind directions at 925 hPa isobaric surface were southwest or partial south during the rice leafroller immigration peaks. Rainfall and vertical perturbation of wind caused rice leafroller mass descent.