Rugilus saudicus, Assing, 2013

Assing, V., 2013, A revision of Palaearctic and Oriental Rugilus. III. Five new species from the Palaearctic region and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (1), pp. 171-190 : 188-189

Rugilus saudicus nov.sp.

( Figs 26-30 )

Type material: Holotype ♂: " SAUDI ARABIA 740 m, Al Bahah, Al Mukhwah, Dhi Ayn Arch. vill., 19°55'46''N, 41°26'30''E, 15.V.2011, leg. Sharaf / Holotypus ♂ Rugilus saudicus sp. n., det. V. Assing 2013" ( KSMA) . Paratypes: 1♂, 1♀: same data as holotype ( cAss) ; 2♂♂, 2♀♀: same data as holotype, but 11.V.2011 ( cAss) ; 1♂, 1♀: " Saudi Arabia, Al Bahan, Al Mukhwah , Dhi Ayn Arch. vill., 23.IX.2011, 19°55'46.5''N, 41°26'34.3''E, 744 m, Leg. M.R. Sharaf, 0046" ( cAss) .

Etymology: The specific epithet (adjective) is derived from Saudi Arabia, where the species was discovered.

Description: Small species; body length 3.4-3.9 mm; length of forebody 2.1-2.3 mm. Coloration: head and pronotum bright reddish; elytra reddish, posterior margins broadly yellow, anterior to this yellow margin usually more or less extensively and more or less strongly tranversely infuscate, occasionally leaving only the anterior third reddish; abdomen dark-brown; legs and antennae yellow.

Head ( Fig. 26 ) distinctly transverse, 1.20-1.25 times as broad as long; posterior outline (behind eyes) smoothly and weakly convex in dorsal view, posterior angles completely obsolete; punctation rather coarse and moderately dense in anterior and antero-lateral portion, and sparse in postero-median portion; interstices without microsculpture and glossy. Eyes conspicuously large and bulging, longer than distance from posterior margin of eye to posterior constriction in dorsal view. Labrum with one distinct toothlike projection on either side of middle. Antenna with antennomere III approximately 2.5 times as long as broad, as long as, or slightly longer than II; IV approximately 1.5 times as long as broad and distinctly shorter than III; V weakly oblong; VI approximately a long as broad; VII-X increasingly transverse; X less than 1.5 times as broad as long.

Pronotum ( Fig. 26 ) small in relation to head, 1.05-1.10 times as long as broad and 0.65- 0.70 times as broad as head; midline broadly impunctate; laterally with rather sparse and fine punctation; interstices glossy, without microsculpture.

Elytra ( Fig. 26 ) approximately as long as pronotum and with pronounced humeral angles; punctation fine and sparse; interstices without microsculpture. Hind wings apparently fully developed. Metatarsus slender, approximately 0.9 times as long as metatibia; metatarsomeres I-IV of decreasing length, but all oblong; metatarsomere I approximately as long as the combined length of II and III, or slightly longer.

Abdomen broadest at segments V/VI, slightly narrower than elytra; anterior impressions of tergites III-V shallow and with dense, coarse punctation; remainder of tergal surfaces with moderately fine and moderately dense punctation; interstices without microsculpture; posterior margin of tergite VII with palisade fringe.

♂: sternite VII in postero-median portion without setae, posterior margin weakly concave; posterior excision of sternite VIII broad and not very deep ( Fig. 27 ); aedeagus ( Figs 28-30 ) approximately 0.38 mm long; ventral process apically bent dorsad (hooked) in lateral view, on either side of ventral process with a moderately sclerotized lateral lobe.

Comparative notes Rugilus saudicus is evidently closely related to R. lucens , as can be inferred from the similar external and male sexual characters. It is distinguished from R. lucens particularly by the different shape of the head (in R. lucens relatively smaller, less transverse, and with moderately marked posterior angles), the sparser punctation of the head, the finer and much sparser punctation of the elytra, and the morphology of the aedeagus. The coloration is similar to that of R. clarissimus (BERNHAUER 1915) from the Afrotropical region, but that species is larger (4.1-4.3 mm), has a less transverse head, much smaller eyes (distinctly shorter than postocular region in dorsal view), and an aedeagus of different shape. For illustrations of the aedeagus of R. clarissimus see FAGEL (1953).

Distribution and natural history:The type locality is situated in Al Bahah in southwestern Saudi Arabia at an altitude of approximately 740 m. The soil is compact clay and humid throughout the year due to irrigation of banana plantations. The specimens were sifted from leaf litter beneath Acacia (SHARAF, pers. comm.).

Figures

Figs 23-30: Rugilus lucens ASSING (23-25) and R. saudicus nov.sp. (26-30): (23, 27) male sternite VIII; (24, 28) aedeagus in lateral view; (25, 29) aedeagus in ventral view; (26) forebody; (30) apical portion of aedeagus in lateral view. Scale bars: 26: 1.0 mm; 23, 27: 0.2 mm; 24-25, 28-30: 0.1 mm.