Bolbochromus (Metabolbochromus) catenatus (Lansberge, 1886)

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

Bolbochromus (Metabolbochromus) catenatus (Lansberge, 1886)

( Figs. 13–14 , 39)

Identification. Basic colour predominantly black or dark-brown, usually with anterior and posterior yellow-orange marking on bottom of lateral declivity of pronotum (they may be contiguous) and one yellow-orange marking near scutellum on elytral base (at least over interstriae 2–3)—colour pattern, however, very variable, at least in parts of its apparently extensive range (note that B. catenatus is on Java and Bali replaced by the two other species in the subgenus). Apicomedian tubercle of clypeus and postfrontal tubercle usually distinct, but short, clypeogenal tubercle on either side lacking (and in this character distinct from B. sulcicollis ). Median sulcus of pronotum distinct, adjacent surface usually evenly convex. Lateral declivity of pronotum with abundant punctation. The more common general colour pattern (black-brown with well delimited yellow-orange markings on pronotum and elytra) also occurs, with slight variations, in other groups of species (mainly continental and Philippines)—these are here allocated to the subgenus Bolbochromus (different aedeagi, different cephalic protrusions, see two of the new species described above). Body length usually 8–11 mm.

Comment. Reported from Sumatra and Borneo, whence longer, most variable series were seen (many collected in flight interception traps by A.J. Davis, in the Danum area, Sabah). The name B. catenatus may stand for a complex of species and/or subspecies, but an examination of more informative material (at least from the Philippines) is needed to draw conclusions. This species, as here tentatively conceived, is the only Bolbochromus common on Borneo; occurring up to approximately 1500 m on Mt Kinabalu (note doubtful records of B. walshi from North Borneo).

Distribution. Indonesia: Sumatra, Borneo, Philippines.

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.