Bolbochromus (Bolbochromus) sinensis Krikken

Krikken, Jan & Li, Chun-Lin, 2013, Taxonomy of the Oriental genus Bolbochromus: a generic overview and descriptions of four new species (Coleoptera: Geotrupidae: Bolboceratinae), Zootaxa 3731 (4), pp. 495-519 : 514-515

Bolbochromus (Bolbochromus) sinensis Krikken & Li, new species

( Figs. 9–10 , 34–36 , 60–61)

Material examined. Holotype male (CAS), from China, labelled “FUKIEN: S China \ Shaowu: Tachulan\ 1942. V.28 T.Maa”; T.C. Maa collector, L. Gressitt collection, identified by H.F. Howden as Bolbochromus catenatus . Paratype female (CAS), labelled “FUKIEN: S China \ Chungani: Sienfeng\-ling to Sanchi\-ang 3.VI.1942 ”, T.C. Maa collector, L. Gressitt collection.

Identification. Parameres unusual: remarkably strongly sclerotised, long, narrowly elongate (upper side view, Fig. 61), remarkably bent (lateral view, Fig. 60), with narrow median lobe (apically finely aculeate), all in all very different from similarly black with yellow-orange, larger species. Median pronotal sulcus with numerous punctures over midline, anteromedian depression with limited punctation, remainder of pronotum also with limited punctation. Postfrons with distinct, short, conical median tubercle, its crest not bifid; clypeus short, anterior border widely arcuate, without any protrusions. Elytra with 7 striae between suture and humeral umbone. Eye foramina small (in full-face view), due to broad, arcuate eye canthi. Most of clypeus and frons moderately densely, evenly, distinctly punctate. General colour glossy black, at least pronotal sides broadly (orange-)yellow; elytra usually with (orange-)yellow prediscal patch and postdiscal streaks; head black. Anterolateral section of pronotum (full-face view) obtusely angular. Known body length approximately 9.5–10.0 mm.

Description (holotype, male). Body length approximately 10 mm. Colour generally black, with symmetric orange-yellow markings on pronotum and elytra; dorsum glossy, almost glabrous. Pilosity on underside and legs abundant, long, light brown.

Labrum with slightly emarginate anteromedian border, limited by fine ridge, upper surface with rugulate transverse elevation. Clypeal surface bordered by fine, widely, evenly arcuate perimarginal ridge, lacking protrusions. Clypeogenal angle not prominent. Clypeus and frons with dense, evenly scattered, distinct primary punctation, interspersed with few fine secondary punctures. Eye canthus with rugulate-punctate surface, generally broad, anterior edge slightly, finely raised, widely arcuate from clypeogenal angle, tapering to temporal lobe; paraocular ridge (issuing from clypeogenal angle) fine, low, extending to near posterior edge of eye foramen. Clypeofrontal transition superficially impressed between clypeogenal angles; postfrontal cone short, tip blunt, unmodified. Eye foramen relatively small.

Pronotum moderately convex, gradually declivous in front, outline of marginate (raised) anterior border evenly arcuate; pronotal midline with punctate sulcus from near base to apex; anterolateral edge obtusely angular, shortly rounded (full-face view), entire lateral edge widely rounded to base. Pronotal surface with double punctation, primary punctation (size slightly variable) distinct, generally sparse, abundant on lateral declivity (at indistinct lateral fovea), also lining anterior and lateral marginal ridge; secondary punctation very sparse, mostly minute. Pronotal base immarginate on section between elytral stria 7 on either side (outline medially simply rounded). Disc black, with narrow extension (to foveolar area); lateral declivity, to border, largely orange-yellow. Scutellum black, with scattered, very sparse fine punctation and micropunctation.

Elytra with discal striae 1, 3, 4, 6, 7 reaching base between suture and humeral umbone; 2 and 5 anteriorly abbreviated, all distinctly impressed, distinctly punctate; punctures separated by 3–6 puncture diameters, slightly crenulating interstriae. Elytral interstriae (on cross-section) distinctly convex, interstriae 2–3 distally less convex than others; interstrial surface sparsely micropunctate. Punctures in juxtepipleural stria with long seta. Interstriae 2–7 with broad, distinct orange-yellow prediscal patch (slightly behind elytral base); interstria 3–5 with elongate orange-yellow postdiscal streak.

Protibia with 8 external denticles, proximally decreasing in size; apex unmodified, with robust, complanate, relatively short tapering spur. Outer side of mesotibiae and metatibiae with 2+(1) and 3+(1) arcuate anteapical fossorial elevations, respectively, their crest fringed with long, robust, acuminate spines; apical crest transversely subelliptic, with similar spines, slightly shorter; terminal spurs long, tapering, apex blunt.

Aedeagus, Figs. 60–61; large, slender, abruptly bent (in profile), narrow in upper side view; median lobe aculeate, all strongly sclerotised (brown, not transparent).

Measurements of respective parts in mm. Median length of head (full-face, excluding labrum and mandibles) 1.9, width 3.0. Median length of pronotum (dorsal) 3.5, maximum width 6.0. Median length of scutellum 1.9, maximum width 3.0. Sutural length of elytra (dorsal) 3.6, maximum width combined 6.0. Variation and sexual dimorphism. The second specimen available is a female from the same province as the male holotype. Generally similar to holotype male, but protibial spur longer, more slender. Body length approximately 9.5 mm.

Distribution. China: Fujian Province.

Figures

FIGURES 9 – 16. Habitus of male Bolbochromus (oblique and lateral views). 9 – 10, B. sinensis; 11 – 12, B. pumilus; 13 – 14, B. catenatus; 15 – 16, B. niger. Scale lines 1 mm.

FIGURES 31 – 36. Bolbochromus holotypes, body parts, head (full-face), pronotum (dorsal), left elytron (dorsal). 31 – 33, B. mindanaicus; 34 – 36, B. sinensis. Scale lines 1 mm.