Rhyacophila kumgangsanica Kumanski 1990

(Figs 8A–8D)

Rhyacophila kumgangsanica Kumanski 1990, 41–42, male (Type locality: Mt. Kumgang-san in North Korea); Park & Kong 2020, 300, list.

Specimens examined. 2 males, Myeonji Mt. valley, Gapyeong-gun, Gyeonggi-do, Korea, 37°56’11”N 127°28’51”E, alt. 250 m, 3.vi.2014, T. Nozaki (NKa) .

Distribution. Rhyacophila kumgangsanica is distributed on the Korean Peninsula (Park & Kong 2020).

Remarks. The male genitalia of this species were precisely described by Kumanski (1990) based on specimens collected from North Korea. Hattori (2005) suggested that this species probably belongs to the R. clemens Species Group. The male genitalia of this species are very similar to those of the Japanese species described or redescribed above in having the following characters: The horizontal part of segment X bears the apical hinged process ventrally (Figs 8A, 8B, 8D); two pairs of anal sclerites have a common internal root (Fig. 8B); a pair of large apical bands surrounds the anus and the root of the anal sclerites (Figs 8B, 8D); and the narrow aedeagus bears a large, long ventral plate (Fig. 8B). Thus R. kumgangsanica definitely belongs to the R. clemens Species Group.

This species is easily distinguished from Japanese species of this species group by the shapes of the apical segment of each inferior appendage and the apical hinged process of segment X: (1) the apical segment of each inferior appendage is rectangular in lateral view (Fig. 8A); (2) the apical hinged process of segment X bears a pair of long lanceolate lobes in dorsal and ventral views (Figs 8B, 8C).