There are 5 ~13 generations in northern China, including 5 ~ 6 generations in Liaoning, 6 ~ 7 generations in Shanxi and 0/2 ~13 generations in Henan. All of them live through the winter in groups of fertilized female mites in various gaps of trees and in soil gaps near dry bases. In the following spring, the average temperature reaches 9 ~10℃. When the fruit tree buds are swollen and exposed to green, they will sting and harm the buds, and when the leaves are spread, they will harm the back of the leaves. At this time, it is the peak period of sting, which lasts for more than 40 days. After feeding for 7 ~ 8 days, they will start to lay eggs, and the peak period is the peak period of spawning. The egg period is 8 ~ 1 0 days, and the eggs basically hatch in 7 ~ 8 days after the flower falls, and the1generation adult mites appear at the same time. The second generation eggs reach the peak of incubation in more than 30 days after the flower falls, and then all the stages coexist and the generations overlap.