Ephemera (Sinephemera) japonica McLanchlan 1875

Ephemera (Sinephemera) japonica McLachlan, 1875 (Figs 19–20, 64) Ephemera japonica McLachlan, 1875: 169 (male imagine and male subimagine; syntypes from Yokohama, Japan). Ephemera japonica — Eaton, 1883: 4; Lestage, 1927: 99, 100; Uéno, 1931: 212; Matsumura, 1931: 1467; Matsumura, 1933: 64; Kimmins, 1960: 308 (lectotype figure); Kimmins, 1971: 315 (type depository); Gose, 1981: 455–457 (key); Tshernova et al., 1986: 105 (key); Ishiwata, 2001: 58 (list); Kawai and Tanida, 2005: 51 (key); Hwang et al., 2008: 161 (list). Ulmer, 1912: 369 (first record from Chinese Taiwan, but maybe wrong, see Kang et Yang, 1996); Ulmer, 1925: 94; Gui, 1985, 96; You and Gui, 1995, 113 (male); Zhang et al., 1995, 75; Zhou, 2013: 185 (list); Zhou et al., 2015: 233 (list). Ephemera (?) japonica — Uéno, 1928: 21 (first description of nymph). Ephemera (Sinephemera) japonica — Kluge, 2004: 235 (subgeneric combination). Description (see McLachlan, 1875 and Uéno, 1928). Diagnosis: (1) This species is unique in terms of the black midline of tergites VI–IX or VII–IX (Figs 19A, 19C, 20A); (2) its tergites and sternites have one pair of oblique stripes respectively but margins of tergites or sternites do not have any stripe (Figs 19, 20A–C). In adults: (3) its wings have no distinct markings except median band (Figs 20D–E); (4) male penes have expanded apices; (5) segment III of forceps is clearly longer than segment IV (Fig. 20F). Remarks: Ulmer (1912) reported this species from Chinese Taiwan province, but Kang et Yang (1996) described only two other Ephemera species from the Taiwan island. But this species possibly distributes in northeastern part of China, so we include it the present fauna. Material examined: Japan: 10 nymphs, 1 ♀ subimagine, Nagano Prefecture, leg. Chang-Fa Zhou, 2012-VI-13. The types of this species are in the British Museum (Kimmins, 1971). Distribution (Fig. 64): Japan, Far east Russia.