Ocypus (Pseudocypus) fuscatus ( Gravenhorst. 1802 )

Smetana, Aleš, 2009, Contributions to the knowledge of the “ Staphylinus-complex ” (Coleoptera: Staphylinidae: Staphylinini) of China. Part 21. The genus Ocypus Leach, 1819, subgenus Pseudocypus Mulsant & Rey, 1876. Section 4, Zootaxa 2286, pp. 1-30 : 18-20

Ocypus (Pseudocypus) fuscatus ( Gravenhorst. 1802)

( Figs. 43–49 , 69)

fuscatus Gravenhorst, 1802 , 164 ( Staphylinus ).

Smetana & Davies, 2000, 44 ( Ocypus ; subg. Pseudocypus ); Herman, 2001, 3378 ( Ocypus , complete synonymy and secondary references included); Smetana, 2004, 677 ( Ocypus ; subg. Pseudocypus , complete synonymy included).

Type material. Gravenhorst (1802: 164) described the species from an unknown number of specimens, without giving the type locality. I have not seen the type material; the concept of the species is the one commonly used by all authors; there is hardly any doubt that this concept is correct.

Material studied: CHINA: Xinjiang: ”China-Xinjiang, 2000–3000 m, SW Borohoro Shan, 40 km ENE QUINGSHUIEZI, 24– 26.7.1993, J. Kaláb leg.” (ɗ) ( NMW).

Diagnosis. Medium-sized species with dark metallic lustre on head and pronotum, with double (coarser punctures intermixed with very fine punctures), irregular punctation on head and pronotum, with sexually dimorphic area behind anterior corners of pronotum, with abdominal tergite 2 finely and densely punctate and pubescent only along apical margin, and with characteristic aedoeagus ( Figs. 45 , 64 ).

Description. Black, head and pronotum with dark metallic lustre, moderately shiny; elytra black, more or less dull, with slight, dark metallic lustre; abdomen black; pubescence on head, pronotum, elytra and abdomen piceous; maxillary and labial palpi testaceous to testaceobrunneous, antennae piceous; legs piceous to piceous black, with more or less paler tarsi, particularly front ones. Head of rounded quadrangular shape, with rounded posterior angles, wider than long (ratio 1.15), eyes moderately large, little convex, tempora slightly longer than eyes from above; dorsal surface of head moderately finely, irregularly and sparsely punctate, with intermixed, very fine punctures, interspaces between punctures on disc considerably larger than diameters of punctures, punctation becoming much denser on tempora and on lateral portions of posterior margin; traces of impunctate midline present; interspaces between punctures without microsculpture. Dorsal side of neck with fine and dense punctation, middle portion almost impunctate. Antenna short, segments 3 slightly longer than segment 2 (ratio 1.18), segments 4 to 7 longer than wide, becoming gradually shorter, segments 8 to 10 about as long as wide to slightly wider than long, last segment short, considerably shorter than two preceding segments combined. Pronotum about as wide as long, subparallel-sided, moderately convex, narrow marginal groove disappearing downwards at about anterior third of pronotal length; impunctate midline complete, punctation fine to moderately coarse, with intermixed very fine punctures, irregular, i.e. leaving variably large areas impunctate; interspaces between punctures without microsculpture. Pronotal hypomeron without microsetae. Scutellum densely punctate and setose. Elytra moderately long, vaguely dilated posteriad, at suture shorter (ratio 0.82), at sides about as long as pronotum at midline; punctation very fine and very dense, granulose, elytra therefore appearing rather dull. Wings fully developed. Abdomen with fifth visible tergite with pale apical seam of palisade setae; tergite 2 (in front of first visible tergite) finely and densely punctate only along apical margin; all tergites evenly, very densely and very finely punctate, punctation becoming gradually somewhat sparser toward apex of abdomen; interspaces with very fine, dense submeshed microsculpture.

Male. Area behind anterior angles of pronotum densely punctate. Sternite 8 with shallow, moderately wide, almost arcuate medioapical emargination. Genital segment with tergite 10 arcuate apically, with numerous long setae on apical portion, otherwise densely and finely setose ( Fig. 43 ); sternite 9 as in Fig. 44 , with narrow basal portion, apical portion vaguely notched medioapically ( Fig. 44 ). Aedoeagus ( Figs.45–48 ) with median lobe in ventral view markedly asymmetrical, extended into subacute apical portion, right lateral portion of median lobe in ventral view straight to evenly arcuate below apex. Paramere situated on median lobe asymmetrically, shaped as in Figs. 47–48 , with subacute apex not reaching apex of median lobe; underside of paramere lacking sensory peg setae, but with minute sensory setae situated as in Fig. 48 .

Female. Area behind anterior angles of pronotum sparingly punctate or almost impunctate. Tergite 10 of genital segment relatively large, evenly narrowed toward subacute apex, without differentiated apical portion ( Fig. 49 ).

Body length 11.0–15.0 mm.

Geographical distribution. Ocypus fuscatus is widely distributed throughout the western portion of the Palaearctic region, eastward through Kazakhstan and western Siberia to Xinjiang and eastern Siberia.

Bionomics. Ocypus fuscatus occurs within its large distributional range in a wide variety of habitats, from lowland to high montane habitats (e.g., at 2500 m in north Tirol, Horion 1965: 222). Occurs both in open country (meadows, pastures, fields, even dry sandy slopes, etc.) and forest habitats. No habitat data are available for the Chinese specimen studied.

Recognition and comments. Ocypus fuscatus may be confused, within the mainland China fauna, only with O. nigroaeneus , but the two species may be easily distinguished in both sexes by the sculpture of the area behind the anterior angles of the pronotum, and by the shapes of the aedoeagi (see Figs. 45 , 52 ). The in habitus similar species O. inexspectatus differs easily by the entirely punctate and pubescent abdominal tergite 2, in addition to the differently shaped aedoeagus ( Fig. 24 ).

Figures

FIGURES 43 – 49. Details of Ocypus fuscatus. 43 — tergite 10 of male genital segment; 44 — sternite 9 of male genital segment; 45 — aedoeagus, ventral view; 46 — aedoeagus, lateral view; 47 — underside of paramere (1.4 mm); 48 — apical portion of underside of paramere; 49 — tergite 10 of female genital segment (1.15).

FIGURES 62 – 67. Abdominal tergite 2 of O. aenescens (62), O. graeseri (63), O. nigroaeneus (64). Apical portion of fifth visible abdominal tergite of O. aenescens (65), O. graeseri (66), O. nigroaeneus (67).

FIGURES 50 – 56. Details of Ocypus nigroaeneus. 50 — tergite 10 of male genital segment (1.25 mm, left side shows proper shape, right side slightly damaged and unnaturally explanate); 51 — sternite 9 of male genital segment (1.6 mm); 52 — aedoeagus, ventral view (1.8 mm); 53 — aedoeagus, lateral view (1.9 mm); 54 — underside of paramere (1.4 mm); 55 — apical portion of underside of paramere; 56 — tergite 10 of female genital segment (1.45 mm).

FIGURES 22 – 28. Details of Ocypus inexspectatus. 22 — sternite 9 of male genital segment (1.3 mm); 23 — tergite 10 of male genital segment (1.3 mm); 24 — aedoeagus, ventral view (2.0 mm); 25 — aedoeagus, lateral view (1.05 mm); 26 — underside of paramere (1.3 mm); 27 — apical portion of underside of paramere; 28 — tergite 10 of female genital segment (1.5 mm).