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1992年棉铃虫发生时间早,落卵量大、产卵历期长,卵始期为6月8日,比1991年提前8天,三、四代重叠,卵量二、三、四代分别为494粒,178粒和95粒(百株),分别为1991年的55倍,14.8倍和2.5倍,累计卵量二、三、四代分别为1114粒,990粒和1202粒分别是1991年的18.6倍,26.1倍和1.26倍,产卵历期二代为33天,三、四代重叠。 由于虫口密度过大,棉农平均每2-3天喷治一遍,仍不能完分控制危害,到三代中后期,约有10％左右的农户防治无望而弃之不管。
In 1992, the bollworm occurred early, with a large amount of eggs and a long oviposition period. The egg period was June 8, eight days earlier than 1991, and the third and fourth generations overlapped. The second, third and fourth generations of eggs were 494, 178 and 95 (100 plants) were 55 times, 14.8 times and 2.5 times of that of 1991 respectively. The total number of eggs in the second, third and fourth generations were 1114, 990 and 1202, respectively, in 1991 18.6 times, 26.1 times and 1.26 times, the second generation of oviposition period is 33 days, three or four generations overlap. Due to the density of insect population is too large, cotton farmers sprayed once every 2-3 days on average, still can not completely control the harm to the middle and late three generations, about 10% of farmers no hope of abandoning control.