关键词: 凹唇壁蜂, 紫壁蜂, 生态位, 苹果, 传粉

Abstract: The niche of the two native bees, Osmia excavata Alfken and O. jacoti Cockerell, released in apple orchards was comparatively studied in eastern China. The result indicates that the niche breadths (B), niche overlaps ? and interspecific comptition coefficients (a) on time (day and seasonal), space, nutrition and nesting dimensions are different in the two species. The niche overlap and interspecific competition coefficient on nutrition between O. eaccavata and O. jacoti are significantly maximal, with values of 0.9690 and0.9994 respectively. Those on day time dimension are 0.7960 and 0.9350.The measure ments of the two species for space and seasonal time dimensions are relatively small and approximate, with C values of 0.6500 and 0.6710, and a values of 0.8213 and 0.8234 separately. These differentiations reduced the competitive relation between the two species. The competition for nesting tubes is the minimum, with a C value of 0.4930 and a a value of 0.6052. The trophic and time niche breadths of O.excavata greater than those of O dactotishow that the former species is more effective in apple pollination for its higher specificity.

Key words: Osmia excavata Alfken, O. jacoti Cockerell, niche, apple, pollination