Abstract: pider is a superior natural enemy of tea green leaf hopper.A three years experiment with four ea varieties of same years old shows that in combining with machine-plucking and straw- ulching between tea rows, spraying pesticide Applaud on the surface of tea plants in early morning or late afternoon of summer when the hoppers are more but spiders are less can give good effects. The frequency of spraying is dropped from 6-7 to 1-2,and the cost for control is de- creased by 113 yuan per hactre. The output of fresh leaves is increased by 5.52%。The popula- tion of spiders is raised by 34.6%,and the density of hoppers is decreased by 37.5%。The eco- logical balance in tea field is greatly improved.

Key words: Robinia pseudoacacia, Populus simonii, site condition, tree age, leaf hydraulic traits, drought resistance.