东北地区草地螟1999年大发生的虫源分析

Immigration of the 1999 outbreak populations of the meadow moth, Loxostege sticticalis L. (Lepidoptera: Pyralidae) into the northeastern part of China

草地螟是我国北方重要的迁飞性害虫 ,对其虫源地及迁飞路线尚缺乏全面的认识。本文分析了 1999年各地草地螟主要迁入峰期的天气学背景 ,并对风场的时空分布及草地螟迁飞轨迹进行了模拟。结果表明 :1999年东北地区大发生的草地螟只有少部分来自以往认为的“主要发生基地” ,其主要虫源来自蒙古共和国东部及中蒙边境地区 ;草地螟盛发期东北地区气旋性天气系统对草地螟的迁入和扩散有密切的关系 ,据此提出可将“东北低压”、“东北低涡”的发生、发展趋势与虫源地的情况结合起来作为监测草地螟迁入的预警指标。

The meadow moth, Loxostege sticticalis L. is an important migratory pest in North China, but its exact overwintering area and migratory path are still not clear. We analyzed the weather background during the major immigration period in 1999, and stimulated temporal-spatial dynamics of wind field and migration trajectories of the meadow moth. The results indicated that only little part of meadow moth population in the northeast of China in 1999 immigrated from “the main occurrence source area' as that people considered before, most of the population should immigrate from the east part of Mongolia and bordering areas of China and Mongolia. The results also showed that cyclone system had notable effect on migration of the meadow moth. So the appearance and enhancement of low pressure or vortex could be a pre-warning indicator for the immigration of outbreak populations of the meadow moth in the northeast of China.