Aleochara (Xenochara) jacobsoni, 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 : 143

Aleochara (Xenochara) jacobsoni KIRSHENBLAT, 1935 ( Figs 21-27 )

Aleochara (Polychara) jacobsoni KIRSHENBLAT, 1935: 336 f.

T y p e m a t e r i a l: Lectotype ♂, present designation: "Gran Kisilkumov i Golod. st. u CyrD G Yakoboson 10.v.03 / [word illegible] N45 / Aleochara jacobsoni sp.n. Kirshenblat det. / Lectotypus ♂ Aleochara jacobsoni Kirshenblat , desig. V. Assing 2017" (ZIN). Paralectotype ♀: same data as holotype (ZIN).

C o m m e n t: The original description is based on an unspecified number of syntypes from "Kasakstan und Turkmenien" ( KIRSHENBLAT 1935). Two syntypes, a male and a female, both in rather poor condition (most of antennae, legs partly missing), were located in the Kirshenblat collection in ZIN. The male is designated as the lectotype. This species had never been revised; its sexual characters were unknown. Therefore, a full redescription and illustrations are provided.

R e d e s c r i p t i o n: Body length 4.2-4.5 mm. Coloration: head, pronotum, and abdomen blackish; elytra reddish-yellow; legs pale reddish-brown; antennae blackishbrown with the basal three antennomeres reddish.

Head ( Fig. 21 ) broadest across or behind eyes; punctation very fine and rather dense; interstices with distinct microsculpture. Eyes large and bulging, longer than postocular region in dorsal view. Antennae not assessable.

Pronotum ( Fig. 21 ) distinctly transverse, moderately convex in cross-section, approximately 1.3 times as broad as long and 1.4 times as broad as head; punctation slightly denser and somewhat more distinct than that of head; interstices with microsculpture.

Elytra ( Fig. 21 ) small in relation to pronotum, only slightly broader than, and approximately 0.75-0.80 times as long as pronotum; posterior margin not distinctly sinuate near lateral angles; punctation dense and more distinct than that of head and pronotum. Hind wings fully developed. Legs very long and slender; metatarsus slightly longer than metatibia; metatarsomere I longer than the combined length of metatarsomeres II and III, but shorter than the combined length of II-IV.

Abdomen slightly narrower than elytra; punctation rather coarse and very dense on anterior, less dense and finer on posterior tergites; interstices without microsculpture; posterior margin of tergite VII with palisade fringe.

♂: sternite VII [sic] posteriorly acutely pointed in the middle ( Fig. 22 ); sternite VIII acutely produced posteriorly; median lobe of aedeagus ( Fig. 23 ) 0.9 mm long (total length 0.98 mm) and of conspicuous shape, very slender and strongly bent subapically in lateral view; internal structures as in Fig. 24 ; paramere ( Fig. 25 ) conspicuously long (length 1.1 mm), even longer than the median lobe.

♀: sternite VII unmodified; posterior margin of sternite VIII obtusely pointed in the middle ( Fig. 26 ); spermatheca shaped as in Fig. 27.

C o m p a r a t i v e n o t e s: Like A. citellorum , A. jacobsoni belongs to the A. parvicornis group, as can be inferred particularly from the morphology of the aedeagus. The species is readily distinguished from all other Xenochara species by the conspicuously long and slender median lobe and parameres of the aedeagus, as well as by the modifications of the male sternite VII.

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: Aleochara jacobsoni was originally described based on material from "Kasakstan und Turkmenien"; subsequent records are unknown to me. The type material was collected in "den Bauen von Spermophilopsis leptodactylus und Rhombomys opimus " ( KIRSHENBLAT 1935), i. e., the burrows of the longclawed ground squirrel and of the great gerbil, both of which are distributed in Middle Asia.

Figures

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.