1967年以来,我们运用物候观测,对稻、麦、棉主要农作物的病虫害开展预测、防治,取得了较好效果。 棉蚜是棉花的主要害虫之一。木槿是棉蚜的中间寄主。秋天,有的棉蚜在木槿上产卵越冬,根据越冬卵的多少(密度)可作为第二年棉蚜发生程度的参考。春季,当木槿芽开放至展叶期,木槿上的棉蚜越冬卵开始孵化。当候平均气温达12℃时,棉蚜开始繁殖,繁殖几代后,就迁飞回棉田。在实践中我们 Since 1967, we have used phenological observations to predict, control and control pests and diseases of major crops of rice, wheat and cotton and achieved good results. Cotton aphid is one of the major pests of cotton. Hibiscus is the intermediate host of cotton aphids. In autumn, some cotton aphids lay eggs on hibiscus overwintering. According to the number of wintering eggs (density), it can be used as a reference for the occurrence of cotton aphid in the next year. In spring, when the hibiscus buds are open to the leaf-setting stage, the aphids on the hibiscus begin to hatch overwintering eggs. When the average temperature reached 12 ℃, cotton aphids began to multiply, multiply generations, they flew back to the cotton field. In practice we