Domene (Macromene) emeiana, Assing, 2015

Assing, Volker, 2015, Three new species of Domene from China (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 65 (1), pp. 31-39 : 36-39

Domene (Macromene) emeiana spec. nov.

( Figs 25–39 , Map 1 )

Type material: Holotype : “P. R. CHINA, Sichuan, Emei Shan, N29°33'51", E103°20'47", 23.v.2011, 1779 m, sift03, V. Grebennikov / Holotypus  Domene emeiana spec. nov., det. V. Assing 2014 ” ( CAS).

Paratypes: 1 : same data as holotype (cSme); 1 : “P. R. CHINA, Sichuan, Emei Shan, N29°33'00", E103°21'38", 28.v.2011, 1639 m, sift08, V. Grebennikov ” (cAss); 5  [listed as Domene sp. in Feldmann et al. (2014)]: “P. R. CHINA, Sichuan, Emei Shan, N29°33.6', E103°20.6', 27.iv.–5.vii.2009, 1800–2400 m, sifting 11–17, V. Grebennikov” ( CAS, cSme, cAss, cFel); 1 [identification based on a photo sent by B. Feldmann; label in Chinese, translated by Zhong Peng]: “ Sichuan, Emei Shan, Jiulaodong [ca. 29°33'N, 103°21'E, 1850 m], Nanchong normal college / 25-VII-1983, collector: I-116” (cRou) .

Etymology: The specific epithet (adjective) is derived from the name of the mountain, where the species was discovered.

Description: Body length 8.0– 9.50 mm; length of forebody 4.4–4.7 mm. Forebody as in Fig. 25 . Coloration: forebody brown, with the humeral angles of the elytra mostly slightly and indistinctly paler; abdomen bicoloured, with segments III–VI dark-yellowish to reddish, segment VII infuscate with the anterior portion broadly, and the posterior margin narrowly yellowish to reddish, segment VIII with the anterior half and the posterior margin yellowish and with a broad transverse brown band in posterior half, segments IX–X darkyellowish to pale-reddish; legs dark-yellowish; antennae dark-reddish, with antennomere XI apically paler.

Head ( Fig. 26 ) of conspicuously subcircular to oval shape, 1.05–1.10 times as long as broad; punctation rather fine, distinctly umbilicate, and very dense, rendering the surface rather matt. Eyes relatively small, 0.3–0.4 times as long as temples from posterior margin of eye to posterior constriction in dorsal view. Antenna ( Fig. 27 ) 3.0– 3.3 mm long and moderately slender.

Pronotum ( Fig. 28 ) slender, approximately 1.25 times as long as broad and 0.95–1.00 times as broad as head, lateral margins subparallel in the middle; punctation similar to that of head; midline with very short and narrow rudiment of a glossy line posteriorly, this glossy line with a fine median furrow.

Elytra ( Fig. 29 ) short and slender, only approximately 0.6 times as long and 0.95 times as broad as pronotum; disc distinctly and extensively impressed anteriorly, without longitudinal ridges; punctation irregular and dense, very coarse in anterior half and less coarse posteriorly, partly rugose; suture elevated; Hind wings completely reduced. Protarsomeres I–IV with distinct sexual dimorphism.

Abdomen 1.2 times as broad as elytra; punctation extremely fine and dense; anterior impressions of tergites III–VI coarsely and somewhat rugosely sculptured; interstices with shallow microsculpture; posterior margin of tergite VII without palisade fringe; tergite VIII with posterior margin obtusely angled or convex in the middle ( Fig. 37 ).

: protarsomeres I–IV strongly dilated; sternites V and VI with shallow and rather small postero-median impression ( Fig. 30 ); sternite VII ( Figs 30–31 ) conspicuously tranverse, more than twice as broad as long (length measured along the middle), with pronounced and extensive median impression, this impression with numerous strongly modified, short and stout black setae in characteristic arrangement, posterior margin broadly concave; sternite VIII ( Figs 30, 32 ) strongly transverse, nearly 1.5 times as broad as long, with a rather pronounced oblong postero-median impression with a (posteriorly denser) cluster of numerous strongly modified, short and stout black setae, posterior margin with a long and nearly acute process on either side of the U-shaped posterior excision; aedeagus ( Figs 33–36 ) approximately 1.5 mm long and of very distinctive morphology; ventral process massive, blade-shaped, and strongly sclerotized; dorsal plate distinctly sclerotized, basally lamellate and apically extending into a narrow and acute process; internal sac with dark sclerites and with apical structure of distinctive shape.

: protarsomeres I–IV distinctly dilated, but somewhat less so than in male; sternite VIII ( Fig. 38 ) distinctly transverse, approximately 1.35 times as broad as long, and with broadly convex posterior margin; tergite IX ( Fig. 39 ) with very short antero-median portion and with relatively short and apically acute postero-lateral processes; tergite X flat and approximately 3.5 times as long as antero-median portion of tergite IX ( Fig. 39 ).

Comparative notes: This highly distinctive species is separated from all other Domene species recorded from China by numerous external and sexual characters, i.e., the coloration of the abdomen, the nearly circular head, the smaller eyes, distinctly shorter and more slender elytra, the conspicuous shapes and chaetotaxy of the male sternites VII and VIII, the completely different morphology of the aedeagus (shapes of ventral process, of dorsal plate, and of internal structures), the strongly transverse female sternite VIII, and the remarkably short antero-median portion of the female tergite IX. Except for D. immarginata and D. affimbriata , it is additionally distinguished from all other Chinese representatives of the genus by the reduced wings and the absence of a palisade fringe at the posterior margin of tergite VII. In fact, D. emeiana is so derived in so many respects that closer affiliations with any other Domene species known from China are not evident.

Distribution and natural history: The adaptive reductions of the eyes, the wings and the palisade fringe at the posterior margin of tergite VII, as well as the absence of records from other regions suggest that D. emeiana is endemic to the Emei Shan in Sichuan ( Map 1 ). The specimens were sifted at altitudes between 1640 and 2400 m.

Figures

Map 1: Distributions ofthe namedDomenespecies inChinaandTaiwan (newspecies:blacksymbols),basedon literature(FELDMANN et al. 2014) and examined records: D. cuspidata (white circles); D. immarginata (white squares); D. praefigens (black circles); D. affimbriata (black square); D. emeiana (black star); other species pooled (white diamonds). For the individual distributions of the pooled species see ASSING & FELDMANN (2014) and FELDMANN et al. (2014).

Figs 25–39: Domene emeiana spec. nov.: forebody (25); head (26); antenna (27); pronotum (28); elytra (29); male sternites V–VIII (30); male sternite VII (31); male sternite VIII (32); aedeagus in lateral view (33); aedeagus in dry preparation in lateral, in ventral, and in dorsal view (34–36); female tergite VIII (37); female sternite VIII (38); female tergites IX–X (39). Scale bars: 25-32: 1.0 mm; 33–39: 0.5 mm.