Oxypoda (Bessopora) grandicristata, Assing, 2016

Assing, Volker, 2016, New species of Oxypoda from Armenia and Georgia (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 48 (2), pp. 1119-1136 : 1130-1134

Oxypoda (Bessopora) grandicristata nov.sp.

( Figs 34-43 )

Type material: Holotype ♂: " ARMENIA [11]- 50 km NW Sisian, Jermuk , 39°50'02''N, 45°40'21''E, 2110 m, oak forest, 30.VI.2016, V. Assing / Holotypus ♂ Oxypoda grandicristata sp. n. det. V. Assing 2016" ( cAss) . Paratypes: 4♂♂, 6 ♀♀: same data as holotype ( cAss) ; 3 exs.: same data, but leg. Schülke ( MNB) ; 2♂♂, 1♀: same data as holotype, but "[11a] ... 3.VII.2016 " ( cAss) ; 8 exs.: same data, but leg. Schülke ( MNB) ; 3♂♂: same data as holotype, but "[11b] ... 12.VII.2016 " ( cAss) ; 1 ex.: same data, but leg. Schülke ( MNB) .

Etymology: The specific epithet (adjective) alludes to the pronounced crista apicalis of the aedeagus.

Description: Body length 2.8-3.5 mm; length of forebody 1.3-1.5 mm. Habitus as in Fig. 34 . Coloration: body more or less uniformly brown to dark-brown; legs reddish; antennae brown, with the basal 2-4 antennomeres usually more or less distinctly paler; maxillary palpi reddish with palpomere III brown.

Head ( Fig. 35 ) approximately as broad as long; punctation dense and distinct; interstices with shallow microreticulation. Eyes small, approximately half as long as postocular region in dorsal view and not protruding from lateral contours of head. Antenna ( Fig. 36 ) 0.8-0.9 mm long and distinctly incrassate apically; antennomeres IV weakly transverse, V-IX distinctly transverse and more than 1.5 times as broad as long, X 1.5 times as long as IX and barely 1.5 times as broad as long, and XI oval, less than twice as long as broad and approximately as long as the combined length of IX and X. Maxillary palpomere III stout, less than three times as long as broad.

Pronotum ( Fig. 35 ) rather strongly convex in cross-section, approximately 1.2 times as broad as long and 1.4 times as broad as head, broadest behind middle; punctation dense and rather fine; interstices with shallow microreticulation.

Elytra ( Fig. 35 ) rather short, 0.80-0.85 times as long as pronotum; punctation very dense, more distinct than that of head and pronotum; interstices with shallow microsculpture; posterior margin moderately sinuate near postero-lateral angles. Hind wings completely reduced. Legs moderately slender; metatibia approximately 0.4 mm long; metatarsus nearly as long as metatibia; metatarsomere I approximately as long as the combined length of metatarsomeres II-IV.

Abdomen with segments III-VI of subequal width, segments VII and VIII weakly tapering posteriad; punctation distinct, very dense on tergites III-VI, somewhat less dense on tergites VII and VIII; interstices without microsculpture; posterior margin of tergite VII with rudiment of a palisade fringe.

♂: sternite VIII with convex posterior margin; median lobe of aedeagus ( Figs 37-39 ) 0.37-0.39 mm long and of conspicuous shape; ventral process strongly arched in lateral view, apex undivided and very slender in ventral view; crista apicalis enormous; paramere ( Fig. 40 ) much longer than median lobe, approximately 0.7 mm long, apical lobe slender and long, but less than half as long as basal portion.

♀: posterior margin of sternite VIII weakly convex, in the middle truncate or weakly concave, with long marginal setae; spermatheca ( Figs 41-42 ) of somewhat variable shape.

Comparative notes: Representatives of the subgenus Bessopora THOMSON, 1859 were previously unknown from Armenia. Oxypoda grandicristata is distinguished from nearly all of the widespread representatives of this subgenus by the short elytra and the absence of fully developed hind wings and from all its congeners by the conspicuous morphology of the median lobe of the aedeagus. The shape of the median lobe somewhat resembles that of O. recondita KRAATZ, 1856 , which is listed in the subgenus Baeoglena THOMSON, 1867 in SCHÜLKE & SMETANA (2015). This subgeneric assignment is clearly erroneous and based on a homoplasy (elongate maxillary palpomere III); other external characters and the morphology of the aedeagus suggest that O. recondita belongs to Bessopora . Aside from the short elytra and the absence of hind wings, the new species differs from O. recondita by darker coloration, more distinct punctation of the whole body, shorter antennae with more transverse antennomeres V-IX, the shape of the male sternite VIII ( O. recondita : posteriorly distinctly pointed), and the morphology of the aedeagus (median lobe smaller; ventral process more strongly arched in lateral view and with more slender apex in ventral view; crista apicalis larger; paramere with longer and basally not distinctly dilated apical lobe).

Distribution and natural history: The type locality is situated near Jermuk in southern Armenia at an altitude of approximately 2100 m. The reduced hind wings suggest that the distribution of O. grandicristata is probably restricted. The specimens were sifted from leaf litter in, and at the margin of, an oak forest ( Fig. 43 ).

Figures

Figs 43: Type locality of Oxypoda grandicristata nov.sp.

Figs 34-42: Oxypoda grandicristata nov.sp.: (34) habitus; (35) forebody; (36) antenna; (37-39) median lobe of aedeagus in lateral and in ventral view; (40) paramere; (41-42) spermatheca. Scale bars: 34: 1.0 mm; 35: 0.5 mm; 36-42: 0.2 mm.