Sphaerobulbus pusio, Smetana, 2005

Smetana, Aleš, 2005, Contributions to the knowledge of the “ Staphylinus-complex ” (Coleoptera: Staphylinidae: Staphylinini) of China. Part 7. The genus Sphaerobulbus Smetana 2003. Section 2, Zootaxa 1006 (1), pp. 53-64 : 58-59

Sphaerobulbus pusio spec. nov.

( Figs. 8–12 )

Type material. Holotype (male): CHINA: “ CHINA Sichuan ( Daliang Shan ) Meigu. Honxi 20.–22.VII. 1996 K. Kitawaki leg.” ( YSC) . Paratypes: CHINA: Sichuan: same data as holotype, 1 ♂ ( ASC); pass Xiahe – Hongxi, Ta Yan Pint , 3000 m, 17.–25.V. 1999, Dr. Vlad. Beneš leg., 1 ♂ ( ASC) .

Description. Piceous­black, abdomen with apical portion of visible tergite 5 (one of the two paratypes) and/or entire visible tergite 6 paler, rufo­brunneous; maxillary and labial palpi testaceous, antennae and legs testaceo­rufous. Head of rounded quadrangular shape, with obsolete posterior angles, wider than long (ratio 1.23), eyes very small and rather flat, tempora considerably longer than eyes from above (ratio 2.12), dorsal surface of disc of head and neck moderately coarsely, rather sparsely punctate and pubescent, with vaguely indicated impunctate midline, punctation gradually becoming markedly denser posterolaterad and posteriad; coarse punctures on disc intermixed with sparse, quite fine punctures; interspaces between punctures with dense, fine meshed microsculpture. Dorsal side of neck coarsely and densely punctate and pubescent. Antenna moderately long, segment 3 longer than segment 2 (ratio 1.18), segments 4 to 7 longer than wide, segments 8– 10 about as long as wide, last segment shorter than 2 preceding segments combined. Pronotum longer than wide (ratio 1.14), almost entirely parallel­sided, narrow marginal groove disappearing downwards mostly just before anterior third of pronotal length; disc of pronotum with complete impunctate midline; punctation and pubescence on disc similar to that on head, gradually becoming denser toward lateral and posterior margins, intermixed quite fine punctures very few, interspaces between punctures with dense, fine microsculpture, similar to that on head. Scutellum sparsely, finely punctate and setose, surface with fine submeshed microsculpture. Elytra short, vaguely widened posteriad, at suture distinctly (ratio 0.70), at sides slightly (ratio 0.80) shorter than pronotum at midline; punctation fine and dense, finely asperate, interspaces between punctures with fine, dense, granulose microsculpture, elytra therefore appearing dull; pubescence brownish­piceous, dense. Wings each reduced to minute, nonfunctional stump. Abdomen with tergite 7 (fifth visible tergite) lacking pale apical seam of palisade setae; tergite 2 (in front of first visible tergite) sparsely punctate; posterior basal line on first three visible abdominal tergites vaguely, obtusely extended posteriad on each lateral portion, all tergites finely, evenly and densely punctate, punctation finer than that on elytra, gradually becoming slightly sparser toward apex of abdomen; interspaces with extremely fine microsculpture of rudimentary striae; pubescence brownish­piceous, dense.

Male. Sternite 8 with narrow and not deep, obtusely triangular medioapical emargination. Male genital segment with sternite 9 widely emarginate medioapically ( Fig. 8 ). Tergite 10 triangular, without differentiated apical portion, with widely arcuate apex, with numerous setae at apex and with only a few additional setae in front of them ( Fig. 9 ). Aedoeagus small, as in Figs. 10–12 ; median lobe parallel­sided in middle portion, with distinctly asymmetrical, acute apex; paramere situated on median lobe markedly asymmetrically, elongate, slightly asymmetrical, with obtuse apex not quite reaching apex of median lobe; underside of paramere with a few inconspicuous, not pigmented sensory peg setae, and with numerous apical setae along left lateral margin (first seta longer than the rest) and with three longer apical setae along right lateral margin ( Fig. 11 ).

Female. Unknown.

Length 9.5–10.5 mm.

Geographical distribution. Sphaerobulbus pusio is at present known only from the type locality in Daliang Shan in southern Sichuan .

Bionomics. Nothing is known about the habitat requirement of this species.

Recognition. Sphaerobulbus pusio is at present the by far smallest species of the genus; it cannot be confused with any other species. It is obviously a member of the “ bisinuatus ­group” of the genus (see Smetana 2003: 69), although the configuration of the basal portions of the first three visible abdominal tergites is not fully developed.

Etymology. The specific epithet is the Latin noun pusio , ­ onis, m. (a little boy) in apposition. It refers to the small size of the species.

Figures

FIGURES 1–12. 1. Sphaerobulbus bisinuatus: apical portion of aedoeagus (ventral view); 2. Sphaerobulbus abdominalis: apical portion of aedoeagus (ventral view). 3–7. Sphaerobulbus rex: 3 — sternite 9 of male genital segment; 4 — tergite 10 of male genital segment; 5 — aedoeagus, ventral view; 6 — underside of apical portion of paramere; 7 — apical portion of aedoeagus, lateral view. 8–12. Sphaerobulbus pusio: 8 — sternite 9 of male genital segment; 9 — tergite 10 of male genital segment; 10 — aedoeagus, ventral view; 11 — underside of apical portion of paramere; 12 — apical portion of aedoeagus, lateral view.