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随着作物种植结构的调整,复种指数的增加,水肥条件的改善,使麦田生态系统发生了变化。导致麦田常发害虫加重为害,次要病虫为害上升,已控制为害的病虫又再度严重回升。据此结合气象条件,对今年我省小麦病虫发生趋势进行预测,并提出建议;供参考。 一、发生趋势 1.小麦蚜虫 进入九十年代,小麦蚜虫发生危害呈上升趋势,我省发生面积3200万亩,占小麦播种面积的95％以上,而且虫口密度高,百株蚜量一般3000～5000头,多者达万头。我省冬小麦田蚜虫优势种群是麦长管蚜,它不耐高温和低温,适宜温度为12～20℃。近年华北广大麦区,在小麦抽穗至溉浆期,气温偏低,雨量偏多,有利于麦蚜发生,而这时气候对天敌不利,加之大量使用化学农药,也减弱了天敌对麦蚜的控制作用,致使麦蚜普遍严
With the adjustment of crop planting structure, the increase of multiple cropping index and the improvement of water and fertilizer conditions, the ecosystem of wheat field has been changed. As a result, the pests in the wheat fields are aggravated and the secondary pests and diseases are on the rise. The pests that have been harmed by the pests have once again risen seriously. According to this combined with meteorological conditions, we forecast the trend of wheat pests in our province this year and make suggestions for reference. First, the occurrence of the trend 1. Wheat aphids into the nineties, the harm of wheat aphids is on the rise, the province occurred an area of 3200 acres, accounting for more than 95% of wheat sown area, and insect population density, aphids amount of a hundred generally 3000 ~ 5000 heads, more than a million heads. The dominant species of aphids in winter wheat field in our province is Aphis gossypii, which is insensitive to high temperature and low temperature. The suitable temperature is 12 ~ 20 ℃. In recent years, a large number of northern part of North China wheat area, heading to the irrigation of wheat milking period, the temperature is low, rainfall is more conducive to the occurrence of wheat aphid, but when adverse weather predators, combined with extensive use of chemical pesticides, but also weakened the natural enemies of wheat aphid Control effect, resulting in wheat aphids generally strict