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抗虫棉中期棉田主要害虫有地老虎、棉蚜、棉叶螨和二代棉铃虫,以瓢虫为主的天敌不仅种类多,而且数量大,对害虫的控制作用强。应采取保护利用天敌为主、化学防治为辅的技术措施,尽量推迟首次用药时间,减少用药次数和用药量,避免直接杀伤天敌。喷药防治应掌握以下要点。为最大限度地保护利用自然天敌,需喷药防治时,应严格按防治指标进行。棉蚜:当受害卷叶株率达5%-10%,或百株蚜量达1000-1500头时,卷叶株率达10%-20%,或百株蚜量达5000-
The main insect pests in the mid-term cotton fields are tiger, cotton aphid, cotton spider mite and the second generation cotton bollworm. The ladybug mainly includes not only many kinds of natural enemies, but also large numbers and strong control effects on pests. Should take protection and use of natural enemies, chemical control supplemented by technical measures, as far as possible delayed the first time medication, reduce the number and dosage of medication to avoid direct killing of natural enemies. Spray prevention and treatment should have the following points. In order to maximize the protection and utilization of natural enemies, need to spray prevention and treatment should be strictly in accordance with the prevention and treatment indicators. Cotton aphid: when the affected roll leaf rate of 5% -10%, or aphid amount of 1000-1500 head, roll leaf rate of 10% -20%, or aphid amount of 5000-