Domene (Macromene) exicta, Assing, 2016

Assing, Volker, 2016, Two new species and additional records of Domene from China and Vietnam (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 66 (1), pp. 113-118 : 116-118

Domene (Macromene) exicta spec. nov.

( Figs 12–22 )

Type material: Holotype : “ CHINA: W-Hubei, 2003, Guanmenshan , 21.6.–13.7., 31.45 N 110.4 E, – 1500 m, leg. J. Turna / Holotypus  Domene exicta sp. n., det. V. Assing 2015 ” (cAss).

Paratypes: 11 : same data as holotype ( NHMW, cAss) .

Etymology: The specific epithet is the past participle of the Latin verb exicare (to cut out) and alludes to the posteriorly excised female sternite VIII.

Description: Very large species; body length 11.0– 12.5 mm; length of forebody 6.5–7.3 mm. Forebody as in Fig. 12 . Coloration: body black, except for the reddish posterior margins of the abdominal tergites VII and VIII and the dark-reddish posterior portions of tergites IX and X; legs blackish-brown to blackish with dark-reddish tarsi; antennae blackish, with the apical 4–5 antennomeres gradually becoming paler, antennomere XI dark-brown with dark-reddish apical portion; maxillary palpi darkreddish to reddish-brown, with palpomere III sometimes partly somewhat infuscate and palpomere IV yellowish.

Head ( Fig. 13 ) 1.00–1.05 times as long as broad and of orbicular shape, broadest behind eyes, and with weakly convex dorsal surface (cross-section); punctation rather fine, umbilicate, and very dense, rendering the surface rather matt. Eyes approximately one-third as long as distance from posterior margin of eye to posterior constriction in dorsal view, or slightly shorter. Antenna ( Fig. 14 ) 4.0– 4.2 mm long and stout.

Pronotum ( Fig. 15 ) 1.12–1.15 times as long as broad and 0.91–0.95 times as broad as head, widest anteriorly and weakly tapering posteriad; punctation similar to that of head, but slightly coarser; midline with or without short and very narrow rudiment of a glossy line posteriorly.

Elytra ( Fig. 16 ) 0.81–0.85 times as long as pronotum; disc without longitudinal ridges, but somewhat uneven, usually shallowly transversely impressed in the middle; punctation dense, somewhat irregular, and somewhat coarser than that of pronotum; interstices narrow and glossy. Hind wings not examined. Protarsomeres I–IV ( Fig. 12 ) without sexual dimorphism, distinctly dilated in male and female.

Abdomen approximately as broad as, or slightly narrower than, elytra; punctation extremely fine and dense, denser and less fine on anterior than on posterior tergites; anterior impressions of tergites III–VI somewhat rugosely sculptured; interstices with distinct microsculpture; posterior margin of tergite VII with palisade fringe; tergite VIII with posterior margin indistinctly angled or weakly convex in the middle.

: sternite VII ( Fig. 17 ) strongly tranverse, nearly twice as broad as long (length measured along the middle), with shallow postero-median impression, with dense and unmodified pubescence, posterior margin broadly and deeply concave; sternite VIII ( Fig. 18 ) weakly transverse and with pronounced oblong median impression, this impression on either side of middle with numerous modified short and stout black setae, posterior excision small, approximately one-seventh as deep as length of sternite; aedeagus ( Figs 19–21 ) 1.4 mm long; ventral process long, stout, strongly sclerotized, and of highly distinctive shape; dorsal plate lamellate and short, much broader than long, apically truncate with pointed middle in dorsal view.

: sternite VIII ( Fig. 22 ) weakly transverse and of charactistic shape; posterior margin convex, in the middle concavely excised, and on either side of this excision with an acute projection; postero-lateral processes of tergite IX apically acute and extending beyond apex of tergite X; tergite X convex in cross-section and slightly longer than antero-median portion of tergite IX.

Comparative notes: As can be inferred from the similarly stout antennae and the similar modifications of the female sternite VIII, both of which undoubtedly represent derived conditions, as well as from the similar head shape, punctation, and male secondary sexual characters, D. exicta is most closely allied to D. firmicornis ASSING & FELDMANN, 2014 from the Tianmu Shan in Zhejiang, together with which it would key out in the key provided by FELDMANN et al. (2014). Both species are reliably distinguished only by the sexual characters, i.e., the shapes and chaetotaxy of the male sternites VII and VIII ( D. firmicornis : sternite VII less strongly transverse and less strongly concave posteriorly; sternite VIII with deeper posterior excision, with less narrow median impression, and with a cluster of modified setae of different shape), the completely different shape of the ventral process of the aedeagus, as well as by the deeper and broader posterior excision of the female sternite VIII. For illustrations of D. firmicornis see ASSING & FELDMANN (2014) and FELDMANN et al. (2014).

Figures

Figs 12–22: Domene exicta spec.nov.: forebody (12); head (13); antenna (14); pronotum (15); elytra (16); male sternite VII (17); male sternite VIII (18); aedeagus in transparent light in lateral view (19); aedeagus in dry preparation in lateral and in ventral view (20–21); female sternite VIII (22). Scale bars: 12–18, 22: 1.0 mm; 19–21: 0.5 mm.