棉小造桥虫是棉花后期食叶性害虫。运城地区曾在1956、1958、1961、1978、1980年大发生,严重地块棉株全部叶片被食光,甚至啃食苞叶和小铃,铃重、衣分和品质大大降低,对产量影响很大。1983年我们对塑膜覆盖棉田棉小造桥虫发生消长动态进行了初步观察。一、观察方法在大面积普遍防治二三代棉铃虫的基础上,在夏县裴介大队选覆盖棉田和露地棉田各一块,从8月5日到9月30日定点定株,每5天调查一次,记载虫株数、幼虫数、卵数、蛹数及为害指数。并定期调查棉花生育状况。为害指数按三级分:0级为健 Cotton is a post-cotton insect pest bridge. Yuncheng area once occurred in 1956, 1958, 1961, 1978 and 1980. All the leaves of the cotton plant in a serious area were eaten, and even the bract and bell were gnawed. The boll weight, lint percentage and quality were greatly reduced, affecting the yield Great. In 1983, we made preliminary observations on the dynamics of the growth and decline of the small-scale, bridged cotton moths in cotton fields. First, the observation method In a large area on the basis of the prevention and control of twenty-three generations of cotton bollworm, Peixuan brigade in Xiaxian election cover cotton fields and open field of cotton each one, from August 5 to September 30 fixed-point set, every 5 days Investigation once recorded the number of insects, larvae, eggs, pupae number and damage index. And regular survey of cotton reproductive status. Harm index by three points: 0 for health