１９９７年河北省棉花种植面积比上年减少３８％，但是全省二、三代棉铃虫各种寄主作物总虫量调查，分别比历年平均值高１６．８７％和８０．３５％。分析比较棉田与棉田以外的各种寄主的棉铃虫虫口数量，可见棉田之外的虫量占绝对优势，成为下一世代发生的主要虫源。调查... In 1997, the area under cotton cultivation in Hebei Province decreased by 38% over the previous year. However, the survey on the total amount of host crops of the second and third generation cotton bollworms in the province was 16.87% and 80.35% higher than the historical average respectively. Analysis and comparison of cotton bollworm population outside the cotton fields and host numbers, we can see that the amount of insects outside the cotton field accounted for the absolute advantage, as the next generation of the main source of insects. survey...