Medon arunicus, 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 : 72-74

Medon arunicus spec. nov.

urn:lsid:zoobank.org:act:69F2F945-73D2-455D-A9E4-AED64A103AE8

( Figs 1–6 )

Type material: Holotype ♂: “E-NEPAL, Arun Valley , W above Tashigaon, 25–2700 m, 26.–27.V.2014, 27°36'33"N, 87°13'28"E, leg. Schmidt / Holotypus ♂ Medon arunicus sp. n., det. V. Assing 2015” ( NME) . Paratypes: 1 ♂, 1 ex.: same data as holotype ( NME, cAss); 1 ♂, 2 ♀♀: “E-NEPAL, Arun Valley , env. Tashigaon, 2200–2400 m, 12.+ 28.–29.V.2014, 27°37'N, 87°14'E, leg. Schmidt ” ( NME, cAss) .

Etymology: The specific epithet is an adjective derived from Arun, the name of the valley where the type specimens were discovered.

Description: Body length 4.0– 4.7 mm; length of forebody 2.2–2.3 mm. Coloration: body blackish-brown to blackish; legs and antennae brown to dark-brown.

Head ( Fig. 1 ) approximately as broad as long; punctation dense and rather coarse, slightly less dense in median dorsal portion; interstices without microsculpture and, except for median dorsal portion, distinctly narrower than diameter of punctures. Eyes of moderate size and moderately convex, approximately 0.7 times as long as postocular region in dorsal view.

Pronotum ( Fig. 1 ) approximately as broad as long and slightly broader than head; punctation about as dense as that of head, but slightly less coarse; midline narrowly impunctate; interstices without microsculpture.

Elytra ( Fig. 1 ) short, 0.70–0.75 times as long as pronotum; punctation dense and fine, rather weakly defined. Hind wings completely reduced. Metatarsomere I nearly as long as the combined length of II and III.

Abdomen slightly broader than elytra; punctation dense and very fine; interstices with shallow microreticulation; posterior margin of tergite VII without palisade fringe.

♂: sternite VII ( Figs 2–3 ) distinctly transverse, posterior margin with broadly V-shaped median excision in the middle, on either side of this excision with two slightly longer and stouter black setae; sternite VIII shaped as in Fig. 4 ; aedeagus approximately 0.5 mm long and shaped as in Figs 5–6 .

Comparative notes: Based on the male primary and secondary sexual characters, M. arunicus belongs to the M. apicalis group and is closely allied to M. manasluensis ASSING, 2010 and related species. The aedeagus and the shapes and chaetotaxy of the male sternites VII and VIII are most similar to those of M. schawalleri ASSING, 2013 from Solukhumbu, which too is an endemic of East Nepal, but differs from the new species by paler coloration (head and pronotum dark-brown; elytra brown; legs dark-yellowish), distinctly sparser and finer punctation of the head and pronotum, smaller and less convex eyes, the shape and chaetotaxy of the male sternite VII (posterior excision narrower, setae on either side of this excision longer, but not stouter than other setae), the shape of the male sternite VIII (posterior excision broader and less deep), and by the shape of the aedeagus (apices slightly longer and less stout). For illustrations of M. schawalleri see ASSING (2013).

Distribution and natural history: The new species was collected in two close localities near Tashigaon in the Arun valley, East Nepal, at altitudes between 2200 and 2700 m.

Figures

Figs 1–12: Medon arunicus spec. nov. (1–6) and M. acutapicalis spec. nov. (7–12): forebody (1, 7); male sternite VII (2, 8); posteromedian portion of male sternite VII (3, 9); male sternite VIII (4, 10); median lobe of aedeagus in lateral and in ventral view (5–6, 11–12). Scale bars: 1, 7: 1.0 mm; 2, 4, 8, 10: 0.5 mm; 5–6, 11–12: 0.2 mm; 3, 9: 0.1 mm.