Study on Radar Observations and Trajectory of the Autumn Migration of Brown Planthopper
褐飞虱迁飞的雷达观测与轨迹研究

We used radar to observe long-distance migration of brown planthopperat Jiangpu in Jiangsu Province during the second half of September,1988.Brownplanthopper dominated the night-flying aerial fauna during the period of observati-ons. Most migrant brown planthopper took off between late afternoon and dusk,cli-mbed to 400 1000m.Trajectory analysis shows that they are dispersing downwind,mainly to the southwest,where insects migrate in the north-easterly winds blowing on the east or south-east sides of a continental anticyclone.centred over northern central China. This direction is ecologically advantageous at this season because it carries the brown planthopper toward areas where survive the winter is possible