Medon emeianus, Assing, 2018

Assing, Volker, 2018, A revision of Medon. XI. Five new species, additional records, and the first confirmed records from the Oriental region (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology (Beitr. Entomol.) 68 (1), pp. 69-81 : 79-80

Medon emeianus spec. nov.

urn:lsid:zoobank.org:act:30FF85B2-BAA4-466A-8544-39A67BC45938

( Figs 26–30 )

Type material: Holotype ♂: “P. R. CHINA, Sichuan, Emei Shan, N29°34'46", E103°22'04", 27.v.2011, 1463 m, sift07, V. Grebennikov / Holotypus ♂ Medon emeianus sp. n. det. V. Assing 2015” ( CAS) . Paratypes: 3 ♂♂, 1 ♀: same data as holotype (cSme, cAss).

Etymology: The specific epithet (adjective) is derived from the name of the mountain where the type locality is situated.

Description: Body length 4.2–5.2 mm; length of forebody 2.4–2.7 mm. Coloration: head blackish; pronotum dark-brown; elytra brown, with the humeral angles indistinctly paler; abdomen brown to dark-brown; legs dark-yellowish; antennae dark-brown to blackish, with the basal 2–3 and the apical 1–2 antennomeres slightly to distinctly paler, occasionally pale-reddish.

Head ( Fig. 26 ) approximately as broad as long; punctation fine and dense; interstices with shallow microreticulation. Eyes large and rather weakly convex, 0.8–1.0 times as long as postocular region in dorsal view.

Pronotum ( Fig. 26 ) 1.00–1.05 times as broad as long and 0.95–1.00 times as broad as head; anterior and posterior margins concave in the middle; punctation dense, fine (though less so than head), and granulose; midline with or without narrowly impunctate longitudinal band.

Elytra ( Fig. 26 ) long and broad, approximately 1.25 times as long as pronotum; punctation fine, very dense, and weakly granulose. Hind wings fully developed. Abdomen narrower than elytra; punctation extremely fine and dense; interstices with shallow microreticulation; posterior margin of tergite VII with palisade fringe.

♂: sternite VII ( Fig. 27 ) with large and concave posterior excision, margin of this excision furnished with a distinct comb of numerous long palisade setae and laterally with additional long black setae; sternite VIII ( Fig. 28 ) small in relation to sternite VII, transverse, and with shallow median impression, this impression with black setae, posterior excision moderately deep and moderately broad; aedeagus ( Figs 29–30 ) approximately 0.8 mm long; ventral process of characteristic shape; internal sac with dark structures in characteristic arrangement.

Comparative notes: Based on the derived shapes and chaetotaxy of the male sternites VII–VIII and on the synapomorphically modified morphology of the aedeagus, M. emeianus undoubtedly belongs to the M. profundus group (see ASSING 2014). It is distinguished from the sympatric M. profundus , which too has been recorded from Emei Shan, by darker coloration of the antennae, slightly smaller average body size, a less deep posterior excision of the male sternite VII, a smaller posterior excision and the different chaetotaxy of the male sternite VIII, and by the differently shaped ventral process and internal structures of the aedeagus. For illustrations of M. profundus and other species of the M. profundus group see ASSING (2014).

Distribution and natural history: The type locality is situated in Emei Shan, Sichuan, at an altitude of approximately 1460 m.

Figures

Figs 26–30: Medon emeianus spec. nov.: forebody (26); male sternite VII (27); male sternite VIII (28); median lobe of aedeagus in lateral and in ventral view (29–30). Scale bars: 26: 1.0 mm; 27–30: 0.2 mm.