棉铃虫是为害棉花蕾铃的一大害虫,在全国各棉区均有分布,而以黄河流域棉区常年发生为害较重。长江流域棉区,历年发生为害的频率较黄河流域棉区为低,但在某些年份为害也甚严重。据了解,近年来棉铃虫的发生有日渐加重的趋势。今春不少地区棉铃虫越冬蛹量 Cotton bollworm is a major insect pest infesting cotton bolls, which are distributed in every cotton area throughout the country, while heavier in the perennial cotton area in the Yellow River. The cotton area in the Yangtze River basin has a lower incidence of damage over the years than in the Yellow River basin but is also seriously damaged in some years. It is learned that in recent years, the occurrence of cotton bollworm has been increasing. Spring in many areas of cotton bollworm wintering pupal amount