Pseudomedon macer, Assing, 2012

Assing, V., 2012, On the Staphylinidae of Socotra Island, Yemen (Insecta: Coleoptera), Linzer biologische Beiträge 44 (2), pp. 973-986 : 982-984

Pseudomedon macer nov.sp. ( Figs 16-23 )

T y p e m a t e r i a l: Holotype: " Yemen, Soqotra Is. , 21.xi.-12.xii.2003, Hadiboh env., ca. 10-100 m, N12°65'02''[sic!] E54°02'04'' [GPS], David Král lgt. / Yemen - Soqotra 2003 Expedition; Jan Farkač, Petr Kabátek & David Král / Holotypus Pseudomedon macer sp. n. det. V. Assing 2012" ( NMNHP) . Paratypes: 1: " Yemen, Sokotra , Al Haghier Mts., Wadi Madar, 12°33'N, 54°00'E, 1180-1230 m, 12.-14.XI.2010, leg. Hlaváč " (cAss) ; 1 ex., Yemen, Sokotra , Dixam plateau, 12°31'N, 53°59'E, 810 m, 1.-2.XII.2003, leg. Kabátek ( NMNHP) ; 1 ex., Yemen, Sokotra , Al Haghier Mts., Scant Mt. env., 12°35'N, 54°02'E, 1450 m, 12.-13.XI.2010 ( NMNHP) .

E t y m o l o g y: The specific epithet (Latin, adjective: slender, meagre) alludes to the conspicuously slender aedeagus.

C o m m e n t: The description is based on the holotype and the first female paratype. The other two specimens were examined and returned to the NMNHP prior to the description.

D e s c r i p t i o n: Body length 3.5-4.0 mm; length of forebody 2.1 mm. Habitus of holotype as in Fig. 16 . Coloration: head, pronotum, and abdomen blackish-brown to blackish; elytra dark-brown; legs brown with paler tarsi; antennae dark-brown with reddish to reddish-brown antennomeres I and II.

Head ( Fig. 17 ) approximately a long as broad; lateral margins subparallel; dorsal surface matt owing to the extremely dense and finely granulose punctation; frons less densely punctured and with subdued shine ( Fig. 20 ). Eyes large, slightly shorter than postocular region in dorsal view. Antennae approximately 1.1 mm long, not particularly slender; antennomere III slender, approximately three times as long as broad and longer than II; IV distinctly shorter than III, slightly less than twice as long as broad; V-VIII of gradually decreasing length and decreasingly oblong; IX approximately as broad as long; X weakly transverse.

Pronotum ( Fig. 17 ) indistinctly transverse and 1.10-1.15 times as broad as head; surface with extremely dense, finely granulose micropunctation ( Fig. 21 ) and additional, moderately dense, shallow, barely noticeable macropunctures; surface matt.

Elytra long and large, 1.15-1.20 times as long as, and much broader than pronotum ( Fig. 17 ); punctation extremely dense, finely granulose ( Fig. 22 ); surface matt. Hind wings fully developed. Protarsomeres dilated in both sexes. Metatarsomere I approximately as long as the combined length of II and III.

Abdomen narrower than elytra; punctation fine and extremely dense; microsculpture distinct; posterior margin of tergite VII with palisade fringe.

: sternite VIII oblong, and with small, broadly V-shaped posterior excision ( Fig. 23 ); aedeagus 0.5 mm long, of conspicuously slender shape ( Figs 18-19 ).

C o m p a r a t i v e n o t e s: In external characters, Pseudomedon species are generally very similar. A reliable identification is usually possible only based on the male sexual characters. The new species is readily distinguished from all those congeners whose generic affiliations have been revised and whose male sexual characters are known by the conspicuously slender aedeagus. In the key to the Palaearctic representatives of the genus by ASSING (2009), P. macer would key out at couplet 10, together with the externally similar, widespread West Palaearctic P. obsoletus (NORDMANN 1837) . It is additionally distinguished from this species by the even denser punctation of the head and pronotum and the slightly shorter and less slender antennae. In P. obsoletus , the interstices on the head and pronotum are very narrow, but noticeable and somewhat shiny. For illustrations of other Palaearctic species see ASSING (2009).

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 species is currently known from four localities in Socotra, where it was found at a wide range of altitudes, from near sea-level to 1450 m. The fully developed wings suggest that P. macer may be more widespread in the Afrotropical region.

Figures

Figs 10-19: Pinophilinus socotranus nov.sp. (10-15) and Pseudomedon macer nov.sp. (16-19): (10, 16) habitus; (11, 17) forebody; (12) abdomen; (13) male sternite VIII; (14-15, 18-19) aedeagus in lateral and in ventral view. Scale bars: 10, 16: 1.0 mm; 11-12, 17: 0.5 mm; 13-15, 18-19: 0.2 mm.

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.