Namibiobolbus Krikken, 1984

Gussmann S. M. & Scholtz, C. H., 2000, Systematic revision of endemic southern African genera of Bolboceratinae (Coleoptera: Scarabaeoidea: Bolboceratidae), Journal of Natural History 34, pp. 1045-1123 : 1069-1075

Namibiobolbus Krikken

(®gures 9a±d, 10a±l, 11a±j, 12a±d, 13a, b, 14)

Namibiobolbus Krikken, 1984: 37 .

Type species: Bolboceras iphicles Kolbe, 1907 , by original designation.

Description

Body length. 10.5±20.8 mm.

Colour. Light to dark brown.

Head. Dorsal surface asetose. Outer margin of mandible rounded but anteriorly more strongly curved inward. Labrum declivous anteriad and posteriad from distinctly elevated slightly arcuate, transverse carina; anterior margin feebly sinuate. Clypeus with feebly to strongly elevated transverse anterior carina; with well-de®ned, short diagonal, posteriorly steeply inclined carina, the latter connecting the anterolateral marginal angle and the respective endpoint of the transverse anterior carina (e.g. arrows ®gure 10g); with distinct lateral carina from endpoint of anterior carina extending to above antennal insertion, from there extending posteriorly in a slightly curved line past eye-canthus on frons, sometimes reaching posterior end of frons (e.g. ®gure 10a). Frons males: with one tubercle, or a strongly elevated bituberculate transverse carina positioned between eye-canthi, or without ornamentation; females: with a strongly elevated trituberculate transverse carina in line with postero-lateral angle of eye-canthus (e.g. ®gure 10c); both sexes: antero-lateral angle of eye-canthus not raised or only feebly raised. Antennal club ovoid, slightly shorter than diameter of eye; glabrous area of basal segment half to two-thirds of exposed surface.

Pronotum. Males: with three protuberances (one median, two lateral) and two to four deep concavities; females: with two small antero-lateral protuberances and one antero-medial transverse carina (can be reduced to bituberculate carina or single protuberance); lateral margin entire.

Scutellum. Deltoid; basal width about 1.2±1.4Ölength; lateral margin medially abruptly curved (e.g. arrows ®gure 10b); with ®ne punctures.

Elytron. Anterior margin not upturned; striae lightly to moderately impressed, their punctures small to very small and separated by two to four and a half puncture diameters; intervals ¯at, with double punctation (®ne and minute punctures); sutural stria terminating at scutellum in a straight line, second stria obsolete near scutellum, neither reaching scutellum nor elytral base.

Prosternum behind procoxae (®gure 9b, c). With protruding median, longitudinal carina near base, sometimes with additional small tubercle at apex.

Metasternum (®gure 9a). Disc more or less ¯at, process medially depressed and with upturned, ridged lateral margins; with longitudinal, median suture reaching meso-metasternal suture; meso-metasternal suture present at the top of the steep, sloping anterior declivity.

Legs. Protibia of normal shape, non-dilated, ®ve-dentate (rarely six-dentate). Protibial spur acuminate; elongate, longer than ®fth tarsomere. Protarsus with ®rst tarsomere shorter than ®fth tarsomere, about as long as tarsomere 2, 3 or 4. Metafemur with punctation and setation of ventral side as in ®gure 9d. Metatibia in lateral view elongate, only slightly broadening apically; with subapical carina feebly to strongly bilobed; with toothlike projections arranged in two rows above subapical carina. Metatarsus lacking subapical setae on tarsomeres 2±4.

Underside. With moderately dense and long setation.

Male genitalia. Compact and broad aedeagal type with parameres consisting of feebly sclerotized, folded membranes.

Distribution (®gure 14). Southern MocËambique, Namibia, north-western and north-eastern parts of South Africa, and probably Botswana.

Comments. Krikken (1977b) placed Bolboceras iphicles Kolbe and the new species heracles in the genus Bolboceroides . Later ( Krikken, 1984) he transferred both species into the newly erected genus Namibiobolbus . Thus the type species Bolboceras capense PeÂringuey remained the only species in the genus Bolboceroides . This latest classi®cation by Krikken is accepted here as there are numerous diOEerences between Namibiobolbus and Bolboceroides . The latter is in fact more similar to Bolboceratex (treated below), whereas Namibiobolbus stands closer to Meridiobolbus (treated below).

One new species is added here to the genus Namibiobolbus .

The combination of the character states mentioned in the generic key as well as a distinct aedeagal type identify the genus Namibiobolbus su ciently. Sexual dimorphism is very pronounced in cephalic and pronotal armature but the females of two of the three species are almost indistinguishable.