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玉米螟是宁城县玉米上的主要害虫。随着玉米种植密度的增加、残存秸秆的增多，玉米螟在全县发生逐年加重。据１９９５年在城关、大明、双庙等１０个乡镇调查，玉米螟钻蛀率为７４％～８５％，平均减产１７．４％，最高减产２２．６％。为有效控制玉米螟的发生危害，从１９９６
Corn borer is the main pest on corn in Ningcheng County. With the increase of corn planting density, the increase of residual straw, corn borer occurred year by year in the county increased. According to the survey conducted in 10 towns and villages in Chengguan, Daming and Shuangmiau in 1995, the corn borer borer rate was 74% -85%, with an average reduction of 17.4% and a maximum reduction of 22.6%. In order to effectively control the occurrence of corn borer harm, from 1996