Holotype. China: Yunnan: ♂, glued on a card with labels as follows: “China, Yunnan Prov., Gongshan County, Heiwadi, alt. 2000 m, 7–10 June 2009, Zhu Jian-Qing & Zhu Xiao-Yu leg. ” “Holotype / Episcaphium zhuxiaoyui / Tang, Tu & Li” [red handwritten label] (SHNU) Paratypes. 5♂♂5♀♀, same data as the holotype (SHNU); 1♂, Deqin County, Nagu Vill., alt. 2250 m, 11.VII.2010, Wen-Xuan Bi leg. (SHNU); 7♂♂5♀♀, Lushui County, Laowo, Fenshuiling, alt. 2250 m, 7.VII.2010, Wen-Xuan Bi leg. (SHNU)

Body length: 5.3–5.9 mm. Pronotum width: 2.0–2.1 mm.

Head black, except for the reddish mouthparts. Inner basal parts of prohypomera, legs including coxal cavity and mesosternum blackish. Other parts reddish.

Frons at narrowest point 0.42–0.44 mm wide. Head coarsely and very densely punctate, punctation coarse on vertex and fine near eyes. Intervals between punctures distinctly smaller than diameter of punctures. Between eyes with a pair of impunctate patches. Labium smooth. Gular striae impressed, groove-like basally.

Pronotum with antebasal puncture row usually interrupted at middle (rarely uninterrupted), impressed laterally. Discal punctures fine and sparse.

Elytra with shallow apical impression and indistinct humeral protuberance; disc with four discal puncture rows consisting of rather coarse punctures anteriorly gradually becoming finer posteriad. All rows start at about basal 2/11 of elytron and end blurrily where puncture rows mix with apical disc punctures. Punctation fine between discal series of punctures and coarse in apical impressions. Mesoventral process with raised, ridge-like edges, and impressed in middle.

Metaventrite finely and sparsely punctate, lacking microsculpture, with medio-apical impression shallow, narrowed anteriorly, and carinate laterally.

Punctation of abdominal sternites very fine and very sparse. Micropunctures absent.

Male sexual characters. Segments 1 to 3 of protarsi slightly widened with dense setae on ventral side. Aedeagus (Figs 5, 6) with median lobe with apical portion inflexed in lateral view. Basal process small, slightly prominent. Parameres slightly sinuate in lateral view. Internal sac (Fig. 7) with a pair of comma-like sclerotized rods.

China (Yunnan).

This new species is similar to the variety of E. semirufum Lewis, 1893 with dark head described from Japan (Figs 3, 4, 8–10), but it may be distinguished from the latter by the different coloration of the ventral side, a pronotum with the antebasal puncture row usually interrupted at middle, and the formation of the discal puncture rows on the elytra: the two outer rows are distinctly separated from the basal puncture row, while in E. semirufum, they fuse with the basal puncture row. The new species is distinguished from all the other species by its coloration.

Figures 1–4. 

Adult habitus of Episcaphium. 1, 2 E. zhuxiaoyui sp. n. 3, 4 E. semirufum Lewis. Scales = 1 mm.

Figures 5–10. 

5–7 E. zhuxiaoyui sp. n. 5 aedeagus in lateral view 6 aedeagus in dorsal view 7 details of internal sac 8–10 E. semirufum Lewis 8 aedeagus in lateral view 9 aedeagus in dorsal view 10 details of internal sac. Scales = 0.25 mm.

This species is named in honor of Mr. Xiao-Yu Zhu who collected some specimens of the new species.

This species was found gathering on an unknown fungus on a huge rotten log across stream, and was observed to become active when night fell (Figs 11, 12).

Figures 11, 12. 

11 Living E. zhuxiaoyui sp. n. on fungus 12 Collector Mr. Zhu Xiao-Yu and log with fungus. Photo by Mr. Jian-Qing Zhu.

China: Gansu: 1♂, Lazikou Valley, 2020–2510 m, 34°09.9–10.1'N, 103°48.2–51.9'E, 28.VI.2005, J. Hájek, D. Král & J. Růžička leg. (NMPC)

This species was previously known from Yunnan and Sichuan. The above male represents the first record from Gansu.