摘要：In a second-order montane stream of the Hanjiang River basin, Leptophlebia sp.and Ephemera sp. appeared to develop two generations per year, and there was little overlap with the two generations in either species. Leptophlebia sp. pupated in autumn and winter, while Ephemera sp. did so in summer and winter. Annual production of Leptophlebia sp., estimated by the size-frequency method, was 7.23 g (dry weight)/m 2 . The annual production of Ephemera sp. was 14.45 g/m 2 . The principal food type and major contributor to this production in both mayflies was amorphous detritus (59.2%), while diatoms contributed 36.4% to the production.
