根据1973—1984年的物候观察,用柳树的物候可预报小地老虎的防治适期,具体情况如下表。注:小地老虎在当地不能越冬,由外地迁入。为了便于群众掌握编成了顺口溜:柳树发青现成虫,柳树发芽蛾高峰,柳絮始飞是适期,及时施药一次净。物候观测,在选定指示树时,必须注意树龄和生长的地点,树木生长的地点和树龄不同.物候现象的出现有早有迟,例如 Based on the observation of phenology in 1973-1984, we can predict the appropriate period of control of O. przewalskii with the willow phenology. The specific conditions are as follows. Note: The small tiger in the local can not wintering, moved in from the field. In order to facilitate the masses to master compiled Jingle: Willow blue-green adults, willow sprouting moth peak, catkins are the first flight is timely, timely application of a net. Phenology observation, in the selection of the indicator tree, we must pay attention to the age and growth of the site, the growth of trees and the age of different locations. Phenological phenomena appear early and late, for example