Lobrathium cavatum, Assing, 2013

Assing, V., 2013, A revision of Palaearctic Lobrathium. IV. Three new species from Nepal and China, a new combination, and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (1), pp. 191-204 : 194-196

Lobrathium cavatum nov.sp.

( Figs 1-6 )

Type material: Holotype ♂: "E-Nepal, 22- 23.6.2000, Kosi prov., Basantapur env., 27.11N 87.27E, 2190 m [GPS], Jan Farkač lgt. / Nepal Expedition, Jan Farkač, David Král & Jan Schneider, 2000 / Holotypus ♂ Lobrathium cavatum sp.n., det. V. Assing 2013" ( NHMB) . Paratypes: 1♂ [aedeagus teratological], 1♀: same data as holotype (NHMB, cAss) .

Etymology: The specific epithet (Latin, adjective: excavate) refers to the pronounced median impressions of the male sternites VII and VIII.

Description: Body length 8.0- 8.5 mm; length of forebody 4.5-4.7 mm. Habitus as in Fig. 1 . Coloration: body black, except for a subcircular and defined reddish-yellow spot near posterior margin of each elytron, this spot reaching neither posterior nor lateral elytral margins; legs blackish with reddish tarsi; antennae reddish-brown to brown.

Head ( Fig. 2 ) approximately as broad as long; posterior angles broadly rounded, weakly marked; punctation areolate and extremely dense, except for the (nearly) impunctate frons and a sparsely punctate or impunctate transverse patch on vertex; interstices in lateral and posterior portions reduced to narrow ridges. Eyes of moderate and somewhat variable size, slightly to distinctly less than half as long as distance from posterior margin of eye to neck. Antenna approximately 2.7 mm long.

Pronotum ( Fig. 2 ) short and broad, 1.16-1.18 times as long as broad and 0.97-1.00 times as broad as head; punctation rather dense; interstices on average slightly narrower than diameter of punctures; impunctate midline moderately broad.

Elytra ( Fig. 2 ) 0.95-0.98 times as long as pronotum; humeral angles marked; punctation much coarser than that of pronotum and dense; interstices without microsculpture. Hind wings probably present. Protarsomeres strongly dilated in both sexes, without sexual dimorphism.

Abdomen slightly narrower than elytra; punctation fine and dense on tergites III-VI, slightly sparser on tergite VII and sparse on tergite VIII; tergites III-VI with shallow anterior impressions, these impressions with pronounced microsculpture and coarse punctures; interstices of remainder of tergal surfaces with fine transverse microsulpture; posterior margin of tergite VII with palisade fringe.

♂: sternite VI with weak and small median impression; sternite VII ( Fig. 3 ) strongly transverse and with pronounced, sharply delimited median impression of triangular shape in posterior half, this impression laterally with numerous strongly modified, short and stout black setae, posterior margin broadly and distinctly concave; sternite VIII ( Fig. 4 ) approximately as long as broad and with pronounced and extensive, sharply delimited median impression in posterior three fourths, this impression with numerous strongly modified, short and stout black setae, posterior excision broad, rather deep, and somewhat U-shaped; aedeagus ( Figs 5-6 ) 1.6 mm long; ventral process large and bladeshaped, with distinct carinae and tooth-like projections ventrally; dorsal plate short and with tooth-like dorsal process.

Comparative notes: Based on the external (punctation of head, broad and short pronotum, elytra with defined reddish-yellow posterior spot, etc.) and particularly the similar male sexual characters (shapes and chaetotaxy of sternites VII and VIII; ventral process of aedeagus blade-shaped and ventrally with carinae and/or tooth-like projections; dorsal plate of aedeagus short and with more or less tooth-shaped posterior process), L. cavatum is closely allied to L. kleebergi ASSING 2012 (central and eastern Nepal), L. guttula (FAUVEL 1895) ( Myanmar) , L. sinuatum ASSING 2012 (central Nepal), and L. bicarinatum ASSING 2012 (N-India, central Nepal). It is reliably distinguished from these species only by the shapes and chaetotaxy of the male sternite VII and VIII, by the shape of the ventral process of the aedeagus (outline in ventral view, shape of the ventral carinae, apex with dorsal projection), and by the shape of the dorsal plate of the aedeagus (in this respect most similar to L. kleebergi , L. sinuatum , and L. bicarinatum ). For illustrations of the compared species see ASSING (2012).

Distribution and natural history: The type locality is situated near Basantapur in Kosi province, eastern Nepal, at an altitude of 2190 m. The male paratype has the aedeagus strongly, teratologically malformed.

Figures

Figs 1-6: Lobrathium cavatum nov.sp.: (1) habitus; (2) forebody; (3) male sternite VII; (4) male sternite VIII; (5-6) aedeagus in lateral and in ventral view. Scale bars: 1-2: 1.0 mm; 3-6: 0.5 mm.