近几年 ,由于作物种植结构的调整和栽培方式的改变 ,棉铃虫已由次要害虫上升为主要害虫 ,成为危害棉花和玉米等作物的大敌。 1999年棉铃虫在我州部分县棉田的危害程度及发生量尤为突出 ,严重田块百株有虫40～ 80余头。二代在棉田发生面积达 2 .7×10 4hm2 ,其三代继续在棉田发 In recent years, due to the adjustment of the crop planting structure and the change of cultivation methods, the bollworm has risen from a major pest to a major pest and becomes the enemy that endangers crops such as cotton and corn. In 1999, cotton bollworm in some counties in our county, the degree of harm and the occurrence of cotton is particularly prominent, serious block 100 insect 40 to 80 heads. The second generation occurred in cotton fields an area of ​​2 .7 × 10 4 hm2, the third generation continued to send in the cotton field