Aleochara (Xenochara) citellorum, Assing, 2018

Assing, Volker, 2018, On the Aleochara subgenera Ceranota and Xenochara. IV. A revision of types, a new species, and additional records (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 50 (1), pp. 129-148 : 141-142

Aleochara (Xenochara) citellorum KIRSHENBLAT, 1935 ( Figs 11-20 )

Aleochara (Polychara) citellorum KIRSHENBLAT, 1935: 336.

T y p e m a t e r i a l: Lectotype ♂, present designation: "Ogdun - Chelopskij plemkhoz, Transbaikalia, Bychkov leg. VIII.1929 / in gopher burrow / Aleochara citellorum sp.n. Type, Kirshenblat det. / Lectotypus ♂ Aleochara citellorum Kirshenblat , desig. V. Assing 2010" (ZIN). Paralectotypes: 3♀♀ [one without head and pronotum]: same data as holotype (ZIN).

C o m m e n t: The original description is based on an unspecified number of syntypes from "Transbaikalien" ( KIRSHENBLAT 1935). Four syntypes, a male and three females, were located in the Kirshenblat collection in ZIN. The male is designated as the lectotype. This species has never been revised; its sexual characters were unknown. Moreover, an examination of the type specimens revealed that the original description is somewhat misleading. Therefore, a full redescription and illustrations are provided here.

The author´s name has been transliterated in various ways. In the article containing the original description it is spelled "Kirschenblatt", whereas it is spelled "Kirshenblat" in the Palaearctic catalogue (SCHÜLKE & SMETANA 2015) and other publications. The latter spelling is adopted in this paper.

A d d i t i o n a l m a t e r i a l e x a m i n e d: Russia: 1♂, 5♀♀, E Siberia, Irkutskaya oblast, Baikal, Olkhon island, Ulan Nur bay, burrows of Citellus undulatus, 5.VI.2010, leg. Vedernikova (cSha, cAss).

R e d e s c r i p t i o n: Body length 4.0- 4.8 mm; length of forebody 1.9-2.2 mm. Coloration: head, pronotum, and abdomen blackish; elytra reddish-yellow, with the sutural region and the anterior margin more or less extensively infuscate; legs reddish to brown; antennae dark-brown with the basal 3-4 antennomeres reddish.

Head ( Fig. 11 ) broadest across eyes; punctation distinct and moderately dense, sparser in median dorsal portion; interstices without microsculpture. Eyes large and bulging, longer than postocular region in dorsal view. Antenna ( Fig. 12 ) short, 1.0- 1.1 mm long; antennomeres IV indistinctly transverse, V much larger than V and more distinctly transverse, VI-X of gradually increasing width and increasingly transverse, X approximately 1.5 times as broad as long, and XI approximately as long as the combined length of VIII-X.

Pronotum ( Fig. 11 ) moderately transverse, strongly convex in cross-section, and relatively small in relation to head, approximately 1.3 times as broad as long and 1.3 times as broad as head; punctation similar to that of head, but denser; interstices narrower than diameter of punctures and without microsculpture.

Elytra ( Fig. 11 ) short, only 0.70-0.75 times as long as pronotum; posterior margin not sinuate near lateral angles; punctation very dense and somewhat asperate. Hind wings fully developed.

Abdomen ( Fig. 13 ) slightly narrower than elytra; punctation coarse and very dense, slightly less dense on posterior than on posterior tergites; interstices without microsculpture; posterior margin of tergite VII with palisade fringe; tergite VIII ( Fig. 14 ) without sexual dimorphism, posterior margin convex and with a row of distinctly modified short and stout setae ( Fig. 20 ).

♂: sternite VIII ( Fig. 15 ) acutely produced posteriorly; median lobe of aedeagus ( Figs 16-17 ) 0.62 mm long, slender, and strongly arched in lateral view.

♀: posterior margin of sternite VIII broadly convex ( Fig. 18 ); spermatheca shaped as in Fig. 19.

C o m p a r a t i v e n o t e s: Based on the external characters (body slender and of subparallel shape, head large in relation to pronotum, median lobe of aedeagus slender and with characteristic internal structures), A. citellorum belongs to the A. parvicornis group ( ASSING 2009a), which previously included two species, A. parvicornis and A. suslica . In external (habitus, coloration, short antennae, large eyes, dense punctation) and the secondary sexual characters, the new species is highly similar to A. parvicornis , but distinguished by the absence of distinct microsculpture on the whole body, less transverse antennomeres IV-X (especially IV!), darker antennomeres V-X, a more transverse head, more distinct punctation of the pronotum and elytra, and particularly the shape of the median lobe of the aedeagus (much more strongly arched). For illustrations of the external and sexual characters of A. parvicornis and A. suslica see ASSING (2009a).

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: The known distribution is confined to East Siberia. The species has been collected from burrows of the Daurian ground squirrel, Spermophilus dauricus BRANDT, 1843 (type material), and of the longtailed ground squirrel, Urocitellus undulatus (PALLAS, 1778) (additional material examined).

Figures

Figs 11-19: Aleochara citellorum (15-16: lectotype; 14, 18: paralectotype): (11) forebody; (12) antenna; (13) abdomen; (14) tergite VIII; (15) male sternite VIII; (16-17) median lobe of aedeagus in lateral view; (18) female sternite VIII; (19) spermatheca. Scale bars: 13: 1.0 mm; 11-12: 0.5 mm; 14-18: 0.2 mm; 19: 0.1 mm.

Figs 20-27: Aleochara citellorum (20) and A. jacobsoni (21-27): (20) posterior portion of tergite VIII; (21) forebody; (22) posterior portion of male abdomen; (23) median lobe of aedeagus in lateral view; (24) apical portion of median lobe in lateral view; (25) paramere; (26) female sternite VIII; (27) spermatheca. Scale bars: 21-22: 1.0 mm; 23, 25-26: 0.5 mm; 20, 24, 27: 0.1 mm.