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麦田粘虫的虫口密度,在地区间、田块间都很不平衡,因而应用防治指标,通过“两查两定”来确定防治对象田,实为必要。根据粘虫的发生危害特点和经济合理地使用农药的要求,麦田粘虫的防治指标究竟以多少为宜?本文就这一问题发表一点意见。麦田粘虫的防治,我省和毗邻省市一般采用每亩6,000头作为防治指标。我县在1972年之前也应用这个指标。1972年病虫观测站观测区大小麦平均虫口每亩3.38万头,经防治后残留虫口平均每亩0.83万头,虽然没有达到防治指标要求,但损失轻微,每亩仅2—3斤。据调查,残留虫口每亩5.5万头,落地麦穗4.75％;每亩1.2万头的,落地麦穗0.48％;每亩0.1万头以下的,落地麦穗0—0.05％。这表明即使
The population density of armyworm armyworms in the region, between the fields are very uneven, so the application of control indicators, through the “two check two set” to determine the field of control, it is really necessary. According to the occurrence characteristics of armyworm and the requirements of using pesticides economically and reasonably, how much control index of armyworm in wheat field is appropriate? This article makes some comments on this issue. Prevention and control of armyworm and armyworm in our province and adjacent provinces and cities generally use 6,000 acres per acre as a control indicator. My county also applied this indicator before 1972. In 1972, the average size of wheat in the observing area of pest and disease station was 33,800 per acre. After the control, the average number of pests per acre was 0.83 million per acre. Though it did not meet the requirements of prevention and control index, the loss was only slight at 2-3 kg per acre. According to the survey, the remnant population of 55,000 mu per mu and 4.75% of the ebb ears; 0.48 per cent of the 12,000 mu of wheat per mu, and 0-0.05 per cent of the wheat ears below 0.1 mu per acre. This shows that even though