Octavius curtissimus, Assing, 2012

Assing, V., 2012, On the Staphylinidae of Socotra Island, Yemen (Insecta: Coleoptera), Linzer biologische Beiträge 44 (2), pp. 973-986 : 977

Octavius curtissimus nov.sp. ( Figs 1-4 )

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, sifted, 12.-13.XI.2010, leg. Hlaváč / Holotypus Octavius curtissimus sp. n. det. V. Assing 2012" ( NMNHP) . Paratypes: 16, 18: same data as holotype ( MNHUB, OÖLL, cAss, cPut) ; 1 ex.: same data, but leg. Hájek ( NMNHP) .

E t y m o l o g y: The specific epithet (superlative of the Latin adjective curtus: short) refers to the conspicuously short elytra.

D e s c r i p t i o n: Body length 1.6-1.9 mm; length of forebody 0.8-0.9 mm. Habitus as in Fig. 1 . Coloration: forebody dark-reddish, often with the elytra slightly paler; abdomen with the base (segments III-V) blackish-brown to blackish and the apex more or less extensively reddish to reddish-brown; legs dark-brown with yellow tarsi, tibiae often yellowish-brown; antennae yellowish.

Head transversely wedge-shaped; punctation coarse, dense, rugose, and largely confluent ( Fig. 2 ). Eyes slightly shorter than postocular region in dorsal view. Antennae short, not reaching posterior margin of head.

Pronotum strongly transverse, approximately 1.5 times as broad as long and 1.2 times as broad as head; posterior margin convexly produced in the middle; on either side of middle with narrow longitudinal impression posteriorly forming an oval pit; lateral portion separated from median portion by extensive impression; punctation coarse, rugose, and largely confluent ( Fig. 2 ); dorsal surface almost matt.

Elytra extremely short, less than half as long as pronotum; each elytron with three folds and laterally sharply edged; punctation somewhat rugose and weakly defined ( Fig. 3 ). Hind wings completely reduced.

Abdomen approximately as broad as elytra; punctation moderately dense and granulose; interstices with shallow, but distinct microsculpture; posterior margin of tergite VII without palisade fringe.

: sternite VIII with moderately deep, broadly V-shaped posterior excision; aedeagus approximately 0.33 mm long and apically very acute in ventral view ( Fig. 4 ).

C o m p a r a t i v e n o t e s: AccordingtoPUTHZ (pers. comm.), the new species is allied to O. flavescens (KISTNER 1961) and related species. It is distinguished from the Afrotropical representatives of this group by the shorter elytra and by the morphology of the aedeagus.

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 only from one locality in the Haghier mountain range, Socotra, where it is probably endemic, as is suggested by the extremely reduced elytra and hind wings. The specimens were sifted from leaf litter and soil at an altitude of 1450 m, together with two undescribed species of Edaphus MOTSCHULSKY 1856 .

Figures

Figs 1-9: Octavius curtissimus nov.sp. (1-4), Edaphus hlavaci nov.sp. (5-8), and E. socotranus nov.sp. (9): (1, 5) habitus; (2) posterior median portion of head and median portion of pronotum; (3) elytra; (4, 8, 9) aedeagus in ventral view; (6) posterior portion of pronotum; (7) aedeagus in lateral view. Scale bars: 1.5: 1.0 mm; 2-4, 6-9: 0.1 mm.