Brachida socotrana, Assing, 2012

Assing, V., 2012, On the Staphylinidae of Socotra Island, Yemen (Insecta: Coleoptera), Linzer biologische Beiträge 44 (2), pp. 973-986 : 984-985

Brachida socotrana nov.sp. ( Figs 24-28 )

T y p e m a t e r i a l: Holotype: " Yemen, Sokotra , Al Haghier Mts., Scant Mt. env., 12°35'N, 54°02'E, 1450 m, 12.-13.XI.2010, leg. Bezděk / Holotypus Pseudomedon macer sp.n. det. V. Assing 2012" ( NMNHP) . Paratypes: 39 exs.: same data as holotype ( NMNHP, cAss) ; 1: same data, but "sifted ... leg. Hlaváč " (cAss) .

E t y m o l o g y: The specific epithet is derived from Socotra, where the species may be endemic.

D e s c r i p t i o n: Species of remarkably variable size; body length 1.7-2.6 mm; length of forebody 0.7-1.1 mm. Coloration variable: head and pronotum blackish; elytra usually blackish, more rarely paler; abdomen blackish, sometimes with the base more or less extensively and more or less distinctly paler; legs brown to blackish brown, with the tibial bases and apices, as well as the tarsi yellowish; antennae dark-brown, with the basal 3-4 antennomeres yellowish.

Head transverse and with very shallow microsculpture, glossy. Eyes large and bulging.

Pronotum strongly transverse, 1.3-1.4 times as broad as head; surface with very shallow microreticulation, glossy; in the middle with four punctures in quadrate arrangement.

Elytra approximately as long as, and distinctly broader than pronotum; punctation sexually dimorphic; surface with distinct microreticulation ( Fig. 24 ). Hind wings fully developed.

Abdomen broad, almost as broad as elytra at posterior margin; tergites with pronounced microreticulation and subdued shine; posterior margin of tergite VII with palisade fringe; tergite VIII with sexual dimorphism.

: elytra in large male with somwhat scale-shaped tubercles scattered on disc, these punctures denser along suture ( Fig. 24 ); tergite VIII near posterior margin with smooth and more or less extensive elevation; sternite VIII with strongly convex posterior margin; aedeagus of variable size, 0.30-0.36 mm long, very slender, and somewhat asymmetric in ventral view ( Figs 25-28 ).

: elytra impunctate and without tubercles; tergite VIII unmodified.

I n t r a s p e c i f i c v a r i a t i o n: This species is subject to remarkable intraspecific variation, not only of body size and coloration, but also of the male primary and sexual characters. In small males, the modifications of the elytra and tergite VIII may be obsolete, and the aedeagus is smaller than in larger males.

C o m p a r a t i v e n o t e s: This species is readily distinguished from its Afrotropical congeners by the much more slender aedeagus, presumably also by the male secondary sexual characters, which are usually not mentioned in the original descriptions. The geographically closest Palaearctic congener is B. hatayana ASSING 2010 from southern Turkey, which is readily distinguished from B. socotrana by completely different coloration alone (body bright reddish with blackish preapical abdominal segments).

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 type locality is identical to that of all other new species described above, except that of Pseudomedon macer . One of the specimens was sifted; no additional collection data are known for the remaining specimens. Since the species is fully winged, it may be more widespread in the adjacent parts of the Afrotropical region.

Figures

Figs 20-28: Pseudomedon macer nov.sp. (20-23) and Brachida socotrana nov.sp. (24-28): (20) antero-median portion of head; (21) median portion of pronotum; (22) sutural portion of left elytron; (23) male sternite VIII; (24) male elytra; (25-28) aedeagus in lateral and in ventral view. Scale bars: 0.1 mm.