A preliminary review of Isonychia Eaton, 1871 from Chinese mainland with a re-description of I. kiangsinensis Hsu, 1936 (Insecta, Ephemeroptera, Isonychiidae)

Previously, seven species of the genus Isonychia Eaton, 1871 were reported in China, but they have never been systematically reviewed. After examining our collections from the Chinese mainland, six species and one additional subspecies have been recognized, compared, and photographed. Among them,I. kiangsinensis is redescribed in all stages and a neotype is designated. Its males have triangular penes and nymphs have three dark pigments on each gill. A synonym of I. guixiensis Wu et al., 1992 (I. sinensis Wu et al., 1992) is confirmed. The males of this species have nearly cylindrical penes and clear abdominal markings. Finally, two species and one subspecies are recorded for the first time in China: I. ussurica sibirica Tiunova et al., 2004, I. ussurica ussurica Bajkova, 1970 and I. vshivkovae vshivkovae Tiunova et al., 2004. Together with the I. ignota (Walker, 1853), I. sexpetala Tiunova et al., 2004, I. formosana (Ulmer, 1912) and possible I. japonica (Ulmer, 1920), they show the rich diversity of the genus Isonychia in China.