A new subgenus of Epeorus and its five species from China (Ephemeroptera: Heptageniidae)
A new subgenus, Siniron subgen. n., is established for five Chinese species of Epeorus Eaton, 1881 to recognize their distinct difference from other subgenera: 1) in nymphs, tergalius I widely expanded anteriorly while tergalius VII curved but unfolded, well developed paired spines on abdominal terga; 2) in adults, unique coloration of wings, penis with distinct median titillators. Among them, nymphal stages of four previously known species, E. (S.) sinensis (Ulmer, 1925), E. (S.) dayongensis Gui & Zhang, 1992, E. (S.) herklotsi (Hsu, 1936b) and E. (S.) ngi Gui, Zhou & Su, 1999, are described for the first time and imaginal stages are also re-described. The fifth species, which has apically pigmented hind wings in imago and protuberances on pronotum in nymph, is described as a new species E. (S.) tuberculatus sp. n. All these species can also be delimited by COI sequences. In addition, their distribution in China is provided.