Oxypoda (Baeoglena) derecta, Assing, 2019

Assing, Volker, 2019, Revision of theBaeoglena species of the West Palaearctic Region (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 69 (1), pp. 1-32 : 28-30

Oxypoda (Baeoglena) derecta spec. nov.

urn:lsid:zoobank.org:act:4C73E05F-20F7-4697-A4BA-D9E030B28A27

( Figs 59–67 , Maps 1 , 7 )

Type material: Holotype: “RU [1] – W-Caucasus, 35 km NNE Sochi, Babuk-Aul , 560 m, forest litter, 43°53'26"N, 39°49'11"E, 11.VII.2011, V. Assing / Holotypus Oxypoda derecta sp. n. det. V. Assing 2018” (cAss) . Paratypes: 2, 6: same data as holotype (cAss); 2, 3: “RU [4] – W-Caucasus, 40 km NNE Sochi, S Mt. Fisht , 1650 m, forest litter 43°55'14"N, 39°51'26"E, 12.VII.2011, V. Assing ” (cAss); 1: “Borcka, Asm., N.O. 1500 m, VI.1972, leg. F. Schubert ” ( NHMW) .

Etymology: The specific epithet (Latin, adjective: straight) alludes to the shape of the crista apicalis of the aedeagus.

Description: Body length 2.2–2.8 mm; length of forebody 1.1–1.3 mm. Habitus as in Fig. 59 . Coloration: body reddish to reddish-brown with the head sometimes records.

61–63); paramere (57, 65); spermatheca (58, 66–67); habitus (59); forebody (60); apex of median lobe of aedeagus in lateral view (64). Scale bars: 59: 1.0 mm; 60: 0.5 mm; 55–58, 61–63, 65–67: 0.2 mm; 64: 0.1 mm.

slightly darker and with tergite VI and the anterior portion of tergite VII infuscate; legs yellowish; antennae reddish with the basal 2–3 antennomeres yellowish-red.

Head ( Fig. 60 ) wedge-shaped; punctation fine and dense; interstices with microreticulation. Eyes flat, slightly shorter than postocular portion of head in dorsal view. Antenna approximately 0.6 mm long; antennomeres IV weakly transverse, V–X of gradually increasing width and increasingly transverse, VII–X approximately twice as broad as long.

Pronotum ( Fig. 60 ) approximately 1.35 times as broad as long and nearly 1.5 times as broad as head; punctation dense, more distinct than that of head; interstices with superficial microreticulation.

Elytra ( Fig. 60 ) short, approximately 0.7 times as long as pronotum; punctation dense, slightly more distinct and less dense than that of pronotum; interstices with superficial microreticulation. Hind wings completely reduced. Metatarsomere I approximately as long as the combined length of metatarsomeres II–IV, or slightly longer.

Abdomen: punctation fine and dense, nearly as dense on tergite VII as on anterior tergites; interstices with shallow microreticulation; posterior margin of tergite VII with narrow palisade fringe; posterior margin of tergite VIII strongly convex.

: posterior margin of sternite VIII broadly convex; median lobe of aedeagus ( Figs 61–64 ) approximately 0.30 mm long; ventral process very weakly curved and apically slightly dilated in lateral view, moderately broad and apically weakly convex in ventral view; crista apicalis long, straight, and narrow; paramere ( Fig. 65 ) approximately 0.5 mm long; apical lobe weakly dilated basally, slightly less than half as long as basal portion.

: posterior margin of sternite VIII truncate; spermatheca ( Figs 66–67 ) with rather long and slender proximal portion and with minute apical cuticular invagination.

Intraspecific variation: The paratype from Northeast Anatolia differs from the specimens from the West Caucasus by slightly shorter elytra (approximately 0.65 times as long as pronotum) and by a somewhat broader crista apicalis of the aedeagus. However, since no additional distinguishing characters were found, these differences are attributed to intra- rather than interspecific variation .

Comparative notes: Oxypoda derecta is distinguished from other West Palaearctic consubgeners (except for the Canarian species) by shorter elytra, completely reduced hind wings, and by the morphology of the aedeagus. As can be inferred from the similar general morphology of the aedeagus (relatively broad ventral process in ventral view; long crista apicalis; similar internal structures) and from the similar structure of the spermatheca (long and thin proximal portion; small apical cuticular invagination), it is most closely related to O. caucasica , from which it additionally differs by slightly smaller size, on average paler coloration, a smaller aedeagus with a less strongly curved and apically less distinctly dilated ventral process (lateral view) and with a much narrower crista apicalis.

Distribution and natural history: The species is currently known only from few localities in the West Caucasus and in the extreme northeast of Turkey ( Maps 1 , 7 ). The altitudes range from 560 to 1650 m. The specimens from the West Caucasus were sifted from litter and dead wood in a forest with Fagus orientalis and Castanea sativa and in a beech forest with scattered fir.

Figures

Map 1: Distributions of theBaeoglena species of the West Palaearctic region exclusive of the Canary Islands, based on revised records:Oxypoda praecox (white stars);O. fusina (black squares);O. nova (white circles);O. kuehnelti (black diamonds);O. rectacia(black triangles);O. caucasica (black circles);O. derecta (white triangles).

Map 7: Distributions ofOxypoda caucasica (black circles) andO. derecta (white triangles) in the Caucasus region, based on revised

Figs 55–67:Oxypoda caucasica (55–58) andO. derecta(59–67): median lobe of aedeagus in lateral and in ventral view (55–56,