Orphnebius formosanus, Assing, 2015

Assing, Volker, 2015, On the Orphnebius fauna of the East Palaearctic region. VI. Six new species from China and Taiwan, and additional records (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini), Linzer biologische Beiträge 47 (1), pp. 101-125 : 111-114

Orphnebius formosanus nov.sp.

( Figs 16-21 , 26-27 )

Orphnebius hauseri: PACE (2010: 23) .

Type material: Holotype ♂: " Taiwan, Nantou Hsien, Meifeng, 2130 m, 4.V.1998, A. Smetana [T197] / Orphnebius hauseri Epp. , det. R. Pace 2005 / Holotypus ♂ Orphnebius formosanus sp. n., det. V. Assing 2013" ( cAss). Paratypes [all dissected prior to present study and labelled " Orphnebius hauseri Epp. , det. R. Pace 2005"]: 1♂: " Taiwan, Taichung Hsien, Anmashan, 2150 m, 13.V.92, A. Smetana [T129]" ( cSme) ; 1♀: " Taiwan, Taichung Hsien, Anmashan , 2230 m, 12.V.92, A. Smetana [T127]" ( cSme) ; 1♂: " Taiwan, Kaohsiung Hsien, Peinantashan trail, 2500 m, 4.VII.93, A. Smetana [T136]" ( cSme) ; 1♂: " Taiwan, Kaohsuing [sic] Hsien, Kuanshan Trail at Kaunshanchi Riv. , 2400 m, 20.VII.93, A. Smetana [T158]" ( cAss) ; 2♀♀: " Taiwan, Kaohsiung Hsien, Kuanshan trail at Kaunshanchi Riv. , 2400 m 20.IV.1992, A. Smetana [T94]" ( MHNG) ; 1♂: " Taiwan, Pingtung Hsien, Peitawushan trail at 1500 m, 1.V.1992, A. Smetana [T110]" ( cAss) .

Etymology: The specific epithet (adjective) is derived from Formosa, the ancient name of Taiwan.

Description: Body length 4.6-5.0 mm; length of forebody 1.9-2.1 mm. Coloration: forebody blackish; abdomen bright reddish, strongly contrasting with the forebody; legs with dark-brown to blackish-brown femora, brown tibiae, and reddish tarsi; antennae with antennomeres V-XI blackish and antennomeres I-IV of variable coloration (reddish to blackish).

Head ( Fig. 16 ) approximately 1.25 times as broad as long; punctation fine and of somewhat variable density, moderately dense to rather dense. Eyes large and bulging, distinctly longer than distance from posterior margin of eye to posterior constriction in dorsal view. Antenna ( Fig. 17 ) 1.3-1.4 mm long, slightly asymmetric; antennomeres V-X increasingly transverse and of increasing width; X more than 1.5, but less than 2.0 times as broad as long; XI distinctly elongated, at least as long as VIII-X combined.

Pronotum ( Fig. 16 ) moderately transverse, 1.17-1.23 times as broad as long; weakly dilated posteriad at most; lateral margins weakly convex in dorsal view; posterior angles weakly marked, rounded; disc with very sparse, minute punctures with long greyish setae; microsculpture absent; lateral margins each with 4-5 setae (often broken off) of moderate length. Elytra ( Fig. 16 ) approximately 0.85 times as long as, and at posterior margin distinctly broader than pronotum; punctation fine and sparse. Hind wings present.

Abdomen ( Fig. 17 ) wedge-shaped, widest at base; tergites III-VI with sharp and pronounced paratergites gradually decreasing in height; tergites III-VI impunctate except for some minute punctures at posterior margins; tergite VII ( Fig. 26 ) with rather coarse non-setiferous punctures in posterior half, but without striate sculpture; posterior margin of tergite VII with pronounced palisade fringe.

♂: tergite VIII posteriorly with two transverse rows of black setae, a submarginal row composed of 6 long setae and a marginal row composed of more numerous and shorter setae; sclerites of segments IX and X modified, with dense and moderately long pubescence; median lobe of aedeagus ( Figs 19-20 ) approximately 0.7 mm long; ventral process rather short; paramere ( Fig. 21 ) 0.60-0.65 mm long; paramerite distinctly longer than condylite and with four long setae at base of velum.

♀: sclerites of segments IX and X with very long and dense dark pubescence; spermatheca as in Fig. 27.

Comment: This species was erroneously recorded from Taiwan as O. hauseri by PACE (2010). The distribution of O. hauseri is confined to North India and Nepal ( ASSING 2006a). The records from mainland China (Sichuan, Yunnan) by PACE (2012) are most likely based on misidentified material, too.

The female from Anmashan is distinguished from the remaining material by extremely sparse punctation of the head and by a distinctly shorter antennomere XI. A clarification of whether these differences are an expression intra- or of interspecific variation is currently not possible. The paramere of the male from Peinantawushan has the apex of the condylite nearly reaching that of the paramerite. Since no additional distinguishing characters were found, this difference is attributed to intraspecific variation.

Comparative notes: Based on the external (coloration, body proportions, punctation, chaetotaxy) and the sexual characters (morphology of the aedeagus and the spermatheca), O. formosanus undoubtedly belongs to the O. hauseri group (see ASSING 2006a, 2006b). The male sexual characters are most similar to those of O. mutabilis from Nepal, from which O. formosanus is distinguished by the much more elongated apical antennomere ( O. mutabilis : only approximately as long as antennomeres IX and X combined), longer antennae ( O. mutabilis : 1.1-1.2 mm), more transverse antennomeres VI-X, the denser punctation and pubescence of the head, the less sparse punctation of the elytra, the less extensive and sparser punctation of the abdominal tergite VII, the different shape of the crista apicalis of the median lobe of the aedeagus, the distinctly larger and differently shaped paramere ( O. mutabilis : approximately 0.35 mm long), and the slightly different shape of the spermatheca. For illustrations of O. mutabilis see ASSING (2006a).

Distribution and natural history: The species is known only from Taiwan, where it was found in several localities in Nantou, Taichung, Pingtung, and Kaohsiung provinces and where it is currently the sole representative of the genus. The specimens were sifted from wet moss and debris along a river, from leaf litter under broadleaved bushes, and from leaf litter in primary broadleaved evergreen and in primary mixed forests at altitudes of 1500-2500 m (SMETANA pers. comm.).

Figures

Figs 16-21: Orphnebius formosanus nov.sp.: forebody (16); antenna (17); abdomen (18); median lobe of aedeagus in lateral view (19); median lobe of aedeagus in ventral view (20); paramere (21). Scale bars: 16-18: 0.5 mm; 19-21: 0.2 mm.

Figs 22-27: Orphnebius incrassatus nov.sp. (22-25) and O. formosanus nov.sp. (26-27): forebody (22); antenna (23); abdomen (24); spermatheca (25, 27); tergite VII (26). Scale bars: 22-24: 0.5 mm; 25-27: 0.2 mm.