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

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. ussurica sibiricaTiunova et al., 2004, I. ussurica ussurica Bajkova, 1970 and I. vshivkovae vshivkovaeTiunova 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.

A new Cinygmula McDunnough, 1933 species with distinct imaginal frontal fold from eastern Chinese Himalaya (Ephemeroptera: Heptageniidae)

“…The origin of large frontal fold in heptageniid imagos has been discussed by Kluge (2015) and we agree to that this character is a relic of their nymphs. Traver (1939), Pescador & Edmunds (1994), Zhou & Peters (2003), Si et al (2017), Ma & Zhou (2021) and Qiang & Zhou (2023) respectively showed some species in the families heptageniidae, oligoneuriidae, Siphluriscidae, Palingeniidae, Neoephemeridae and Isonychiidae have distinct frons, frontal fold or produced epicranium on imaginal head. At the same time, the nymphs of them also have elongated head or frons.…”