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一、豫北棉蚜的发生特点和防治问题棉蚜是豫北棉田前、中期的主要害虫。它的发生特点是:早、重、长、无间歇。早,发生早,棉苗出土就上棉蚜,出苗早的,棉蚜上得也早。重,为害重,棉蚜达到一定数量,就引起真叶卷缩,棉苗生长停滞,生育期推迟,造成减产;蕾期棉蚜猖獗,更会引起幼蕾大量脱落,对产量的影响尤为严重。长,持续时间长,
First, the occurrence of cotton aphid in North Henan characteristics and prevention and treatment of cotton aphid cotton field in North Henan before, the main pests. Its occurrence is characterized by: early, heavy, long, non-stop. Early, early, cotton seedlings unearthed on the cotton aphid, early emergence, cotton aphid too early. Heavy, serious damage, a certain number of cotton aphids, causing true leaf curling, growth of cotton seedling stagnation, delayed growth period, resulting in reduced production; bud stage cotton aphid rampant, but also cause a large number of young buds off, the impact is particularly serious on the yield . Long, long duration,