Abstract
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.guixiensisWu et al., 1992 (I.sinensisWu 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.ussuricasibiricaTiunova et al., 2004, I.ussuricaussurica Bajkova, 1970 and I.vshivkovaevshivkovaeTiunova et al., 2004. Together with the I.ignota (Walker, 1853), I.sexpetalaTiunova et al., 2004, I.formosana (Ulmer, 1912) and possible I.japonica (Ulmer, 1920), they show the rich diversity of the genus Isonychia in China.