Effects of Pruning on Biodiversity of Arthropod Communities at Organic Tea Plantations

Effect of plant pruning on the biodiversity of arthropod communities at organic tea plantations were investigated in the summer. Tea plants were subjected to light, deep or no pruning for observation in changes on the biodiversity at the plantations. The results indicated thatone or two months after alight pruning,both pests and natural enemies were significantlyaffected. The effect was even greater whena deep pruning was applied. A month after a deep pruning,the number of arthropods includingEmpoasca vitis, Ectropis obliqua, Acaphyllatheaeand spiders were significantly reduced as compared with that without pruning. However, one month later,theEmpoasca vitiscounts began to increase. Both light and deep pruning delayed the initial peak on the small green leafhopper count, and the deep pruning completely avoided the damage caused by the tea pink mites. In 3 or 4 months, no significant difference in arthropod community diversity index,nor the ratio of natural enemy/pest biomass, was observed among the treatments. Light pruning couldputthe leaf-sucker population in the plantations under controlfor as long as one month. Although deep pruning showed an even greater effect with respect topest reduction and natural enemy protection, the accumulated and subsequent tea production needed to be considered as well for a balanced benefit.