Overwintering spider mite community in orchard and the interspecific association

：The investigation of community of overwintering spider mites in the orchards were carried in WuWei(N38°, E103°), Gansu. There are four species, Eotetranychus pruni (Oudemans)、Tetranychus viennensis Zacher、Panonychus ulmi Koch and Bryobia rubrioculus (Scheuten) founded in the orchards. Different orchard has different community and its species association. The apricot orchard has more similar community with the pear orchard, but more different from apple orchard by cluster analysis. The community where a tree was used a sample unit is composed of dominantly 1 or 2 species, less frequently 3 species. The community of 4 species had not been found. It is clear that the interspecific association is different in different orchards by 2×2 table or 4-fold table. The study on community and interspecific association of overwintering spider mites is significant in the pest community management.