近些年来,我区盐池、灵武一带沙枣尺蠖,对榆树、沙枣等威胁甚大。自1970年以后连年采用人工喷药,因为林地面积大,即便使用机动喷雾器防虫,喷雾时间也拖得较长。这样,防治初期刚孵化的幼虫,在一个月以后,也将老熟入土,不能达到预期的防治效果。从1976年我区开始采用飞机灭虫,虽然喷药时间短,防治效果显著,但由于不能准确掌握卵的孵化期,飞防时往往虫卵尚未全部孵化,因而不能控制虫害。如1977年盐池城南林场飞机防 In recent years, I salt ponds, Lingwu area near the jujube scales, the elm, jujube and other threats. Since 1970, successive years of artificial spraying, because of the large area of ​​forest, even with the use of motorized sprayer pest control, spray time is also dragging longer. In this way, early hatchling control early larvae, a month later, will also be cooked into the soil, can not achieve the desired control effect. Since 1976, my area began to use the plane to kill insects, although the spraying time is short, the control effect is remarkable. However, the hatching period of the eggs can not be accurately grasped. As 1977 Yanchi Chengnan forest farm aircraft defense