论文部分内容阅读
通过室内饲养与田间调查相结合的方法,证实1994年棉铃虫完成了五个世代。越冬蛹羽化提前,与常年比较一代提前2-5d,二代提前6—7d,三代提前8—10d,四代提前13—15d。究其原因,4月份气温回升快,6—9月最适宜棉铃虫发育的日数是100d,超过常年30d,积温较常年高166.1℃,持续长时间的适温使棉铃虫历期缩短,2—4代幼虫历期为13—15d,蛹期8—10d,三个世代累计幼虫期和蛹期与常年比较分别缩短了10—21d与8—13d。棉铃虫自麦田一代始至9月下旬玉米、棉花等大秋作物收获时已完成了五代历期,大部分成为越冬滞育蛹。
Through a combination of indoor feeding and field surveys, it confirmed that the cotton bollworm had completed five generations in 1994. Overwintering pupae emergence in advance, compared with the perennial generation 2-5d ahead of the second generation ahead of 6-7d, the third generation early 8-10d, the fourth generation advance 13-15d. The reason was that the temperature picked up rapidly in April, and the optimum number of days for cotton bollworm development in June-September was 100d, which exceeded that of the normal year by 30 days. The accumulated temperature was 166.1 ℃ higher than that of normal years. The long duration of suitable temperature shortened the duration of cotton bollworm. The larvae of the 4th generation lasted for 13-15 days, and the pupal stage for 8-10 days. The cumulative larval and pupal stages of the three generations were shortened by 10-21 days and 8-13 days respectively compared with the normal years. Cotton bollworm from the wheat field until the beginning of late September corn, cotton and other big autumn harvest has completed five generations, most of the winter diapause pupae.