Study On The Effect Of Intercrop On Promoting Biodiversity And Controlling Moths In Tea Gardens On Hills

From september of 2007 to October of 2008, a survey to arthropod communities in pure tea garden, tea and chestnut intercrop garden, tea and Japanese persimmon intercrop garden, tea and peach intercrop garden was executed at an interval of ten days. By means of mathematical ecological method, the effect of various fruit trees on biodiversity and stability of arthropod communities as well as the effect of ecological control on tea garden eco‐system on moths were analyzed, so as to choose the optimum intercrop model to be suitable for the hills. The results are as follows:1 Twenty orders belonging to three classes were recorded, in which fifteen orders of two classes of pest, and eight orders of three classes of natural enemies were included. Homoptera, Diptera, Araneida, Himenoptera and Lepidoptera are the dominant groups, in which leafhoppers are the main pests, and araneids are the dominant natural enemies. The ecological effect of tea and chestnut intercrop garden are obvious, and the model can be extended.2 Tea green leafhopper, green broad-winged planthopper, and moths damaged the tea plants in short time easily. Araneids, ladybird beetles, ground beetles, parasitic wasps and parasitic flies can control pests to some extension.3 The number of leafhoppers and bugs in pure tea garden were larger than those in tea and chestnut intercrop garden, and tea and peach intercrop garden. The number of araneids and parasitic wasps in tea and chestnut intercrop garden, the number of araneids in tea and persimmon intercrop garden, and the number of parasitic wasps in tea and peach intercrop garden were larger than those in pure tea garden. In pure tea garden species richness was few, the ratio of the beneficial to the harmful was low, and the ecological potential was weak. The ratio of the beneficial to the harmful was the largest, and the effect of ecological regulation was the strongest.4 The communities of pests and natural enemies flourished from April to October, and keeped stable from July to September. The pests damaged tea plants seriously from May to the middle June. The population of pests came into being two or three peaks. The fluctuation of number of natural enemies went with that of number of pests; moreover, the change of natural enemies was relatively even.The community stability of arthropods in this four kind of tea gardens are arranged by this order : tea and peach intercrop garden > tea and chestnut intercrop garden > tea and Japan-ese persimmon intercrop garden > pure tea garden.5 The intercrop of tea with peachs, chestnuts and persimmons alterred the composition of tea garden eco-system, improved the biodiversity enhanced the stability of the communities, and strengthen the ecological potential.The tea and peach intercrop garden has the least individual number of the moth and the biggest ratio of the natural enemy individual number to the moth's among three intercropping tea gardens. The effect that the tea and peach intercrop garden controlls moths was the strongest, the second is tea plant intercropped with chestnut, and tea plant intercropped with Japanese persimmon is the worst.