Leuctra fusca tergostyla Wu, 1973 comb. n.

(Figs. 1–3)

Leuctra tergostyla Wu, 1973 — Wu 1973: 115. (original description of the male).

Leuctra fusca (Linnaeus, 1758) — Kim et al. 1998: 422. (first record from South Korea).

New material. NORTH KOREA: GW, Goseong-gun, Gumgangsan (Mt.), singled along footpath from Gumgangmun Gate to Guryong Falls, N38°40’ E128°10’, 12.x.1978 (loc. Korea.487), leg. A. Vojnits, L. Zombori: 2♀ (HNHM) . GW, Goseong-gun, Gumgangsan (Mt.), swept from ferns, N38°40’ E128°10’, 12.x.1978 (loc. Korea.488), leg. A. Vojnits, L. Zombori: 8♂ 12♀ (HNHM) . GW, Goseong-gun, Gumgangsan (Mt.), singled along the way to Guryong Falls, N38°40’ E128°10’, 18.ix.1980 (loc. Korea.692), leg. L. Forró, Gy. Topál: 5♂ 7♀ (HMHM) . GW, Goseong-gun, Gumgangsan (Mt.), netting at Guryong Falls, N38°40’ E128°10’, 18.ix.1980 (loc. Korea.696), leg. L. Forró, Gy. Topál: 1♀ (HNHM) . GW, Goseong-gun, Gumgangsan (Mt.), netting along the way to Guryong Falls, N38°40’ E128°10’, 18.ix.1980 (loc. Korea.697), leg. L. Forró, Gy. Topál: 9♂ 8♀ (HNHM) . SOUTH KOREA: CB, Danyang-gun, Yeongchun-myeon, Namcheon-ri, Namcheon, Sobaeksan (Mt.), 3.xi.2015: 2♀ (KU). CB, Danyang-gun, Yeongchun-myeon, Namcheon-ri, Namcheon, Sobaeksan (Mt.), 7.xi.2014: 3♂ 3♀ (KUEM) .

Distribution. This Far East subspecies of L. fusca is known from China (described from eastern Qinghai Province of western China on the Tibetan Plateau (Yang et al. 2014)) and specimens illustrated herein are from the vicinity of Beijing, northeastern China), Korean Peninsula, and the Russian Far East (confirmed by Valentina Teslenko). Western boundary of its distribution needs to be clarified. Mongolian specimen illustrated in Judson & Nelson (2012) seem to be L. fusca fusca (Linnaeus, 1758) . Leuctra f. tergostyla is new for North Korea (Fig. 27).

Remarks. The Korean and Chinese specimens exhibit slight morphological differences that distinguish them from the West Palaearctic subspecies. The male has larger and more erect tergal projections on tergum VI, larger and undivided mesal sclerites on terga VIII–IX and the base of paraproct is smaller and less swollen in lateral view (Figs. 1–2). The female has more rounded lobes of the subgenital plate (Fig. 3), whereas the sclerotized ridge between the lobes is wider than that of L. f. fusca but not as wide as of L. f. latior Berthélemy & Dia, 1982. On the basis of Wu’s original description and figures (Wu 1973), his species L. tergostyla Wu, 1973 is conspecific with L. fusca . Unfortunately, the types are considered lost, but the name is available. Molecular studies showed large genetic variability of West Palaearctic populations of L. fusca (Boumans & Tierno de Figueroa 2016), thus, it seems to be more appropriate to use the name L. tergostyla to distinguish a Far Eastern subspecies rather than in synonymy with L. f. fusca .