Bolbochromus (Metabolbochromus) niger Pouillaude, 1914

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 : 515-516

Bolbochromus (Metabolbochromus) niger Pouillaude, 1914

( Figs. 15–16 , 40)

Identification. Entirely black (-brown), without yellow markings (outside Java and Bali replaced by its patterned, much more variable relative B. catenatus , diagnosed above). Apicomedian tubercle of clypeus and postfrontal tubercle both very distinct. Median sulcus of pronotum distinct, adjacent surface slightly depressed in front.

Clypeogenal angles without tubercle (and in this distinct from B. sulcicollis , which occasionally has a uniform black dorsum). Lateral declivity of pronotum with abundant punctation. Elytral interstriae strongly convex. Usually more robust than B. catenatus , and apparently not sympatric. Body length of B. niger usually 10–13 mm (the male from Bali, here pictured, is remarkably large).

Comment. Considering the variation in B. catenatus , this taxon might perhaps be considered one of its subspecies, but since the overall taxonomy of B. catenatus is unclear, no action is taken.

Distribution. Indonesia: Java, Bali.

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.