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河北是全国重点产棉大省,它的丰欠对我国棉花总产量具有举足轻重的影响。从1992年开始棉花连续锐减,棉铃虫发生危害是造成棉花大幅度减产的重要原因。 棉铃虫在我省连续三年大发生。1992年至1994年都是代代大发生。特别是1993年一二代更为史无前例的大暴发,全省麦田一代棉铃虫一般每平方米有卵20～200粒,多的300～400粒,非主产棉区一般每平方米有卵20～30粒,均高于历史平均值。据统计,二代全代
Hebei is a major cotton-producing province in the country and its abundance owes a decisive influence on the total cotton output in China. Since 1992, the continuous sharp drop of cotton, cotton bollworm harm is caused by a significant reduction in cotton production an important reason. Cotton bollworm occurred in our province for three consecutive years. From 1992 to 1994, all occurred from generation to generation. Especially in the first and second generation in 1993, an even more unprecedented outbreak occurred. Cotton bollworms of the province’s first generation of cotton bolls generally have 20 to 200 eggs per square meter and 300 to 400 more grains, and non-cotton-producing areas generally have 20 eggs per square meter ~ 30 tablets, all higher than the historical average. According to statistics, the second generation of the whole generation