Control of Castanea mollissima Red Spider

Chestnut red spider said needle small claw mite, damage chestnut leaves, so that the leaves fade green into yellow and white spots, serious leaf withered brown, resulting in yield reduction. Winter eggs are laid on the leaf scars, thick skin gaps and branches on the back of 1-4-year-old branches, and they begin to hatch from late April to early May of the next year. At this time, it is the germination period of chestnut buds. In the middle of May, young mites climb on new leaves to damage. Red spiders occur 4-9 generations a year. The second generation to the fifth generation mites are most harmful. The time is generally between June and July. The suitable temperature is 24-25 ℃. In high temperature and drought years, it occurs early and heavily. In sunny chestnut orchard, it occurs earlier and more serious than in shady chestnut orchard. Control methods: May scraping trunk thick skin 5-10 cm circle, the exposed tender skin can be used 40% omethoate emulsifiable solution 2-5 times painted on the trunk, and then wrapped with plastic film. 20% amitraz EC 2000 times or 20% dicofol EC 1000 times can also be used for foliar spraying from late May to late June.