Life history flexibility of Drunella submontana Brodsky, 1930 (Ephemeroptera: Ephemerellidae) along altitude gradients in Shennongjia National Park, China

摘要

We investigated the life history of Drunella submontana Brodsky, 1930 using the size-frequency method at four sites at different altitudes (from 590 m to 2180 m) in Shennongjia National Park, Central China. Monthly samples of larvae were taken over a two-year period (May 2015-April 2017). Drunella submontana was considered exhibit three overlapping life cycle types: univoltinism with a short egg stage, univoltinism with a long egg stage and semivoltinism. Under diverse climatic habitats in the river ecosystem in Shennongjia National Park, some physicochemical parameters (such as temperature, conductivity, salinity, total dissolved solids and pH) of water showed significantly differences, and the developmental time of D. submontana prolongated from low to high altitudes. High larva density and the short egg stage appeared in middle altitude.