20 0 1年夏季严重干旱 ,大同市种子公司一个 12 0 0亩的玉米制种基地由于红蜘蛛失控成灾 ,给制种农户和种子公司造成了很大的经济损失。原计划产种 4 0万kg,结果只产了 2 0多万 kg,减产将近 5 0 %。由此可见 ,红蜘蛛对玉米制种田的危害是触目惊心的 ,绝不可低估。为此 ,必须对? In the summer of 2007, due to a severe summer drought, a 120-acre maize seed production base in Datong’s seed company caused great economic losses to the seed farmers and seed companies due to the uncontrolled development of the spider mites. The original plan was to produce 40,000 kg of seeds and only 20 million kg of them were produced and the yield was reduced by nearly 50%. Thus, the red spider on the hazards of corn farming is shocking, must not be underestimated. To this end, must?