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近两年来黄地老虎在我场为害严重,特别是冬白菜受害更重.1957年白菜受害率约30%左右,严重的达40%,造成大量缺苗.如生产一队20多亩白菜,受害无收.虫口密度一般每株周围达十几条,最多达32条.1958年在刚定苗时为害株率一般15—25%左右,最高达63%;虫口密度,一般为7—8条,最多为19条,劳改一队100亩白菜就有30多亩遭到毁灭.因此,为了保苗增产,采取有效措施防治黄地老虎为害,是迫切必要的.我们试用666和滴滴涕液灌治,灌药前后,随机取样,调查虫口密度,灌后3日,检查死虫数,由于防治时间稍晚,幼虫多为2—3龄,部分为4龄,一龄的较少.
In the past two years, yellow tigers in our field seriously damaged, especially the winter cabbage victimization heavier .1957 cabbage victimization rate of about 30%, a serious 40%, resulting in a large number of lack of seedlings, such as the production of a team of 20 acres of cabbage, Harmless income insects density generally per plant around up to a dozen, up to 32. In 1958 just set the plant damage rate is generally about 15-25%, up to 63%; insect population density, usually 7-8 , Up to 19, a reform team of 100 acres of cabbage have been destroyed more than 30 acres.Therefore, in order to increase seedling yield, take effective measures to prevent yellow tiger damage, it is imperative.We tried 666 and DDT liquid irrigation treatment, Before and after irrigation, random sampling, investigation of population density, on the 3rd after irrigation, check the number of dead insects, as the control time later, mostly larvae 2-3 years, part of the 4-year-old, less age.