Bolboceratex Krikken

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 : 1098-1100

Bolboceratex Krikken

(®gures 24a±e, 25a±h, 26a±h, 27a±d, 28a±l, 29a±j, 30a±d, 31a±c, 32a, b, 33a, b, 34, 35) Bolboceratex Krikken, 1984: 33 .

Type species: Bolboceras posticatum Boheman, 1860 , by original designation.

Bolbodius Krikken, 1984: 35 . Syn. nov.

Description

Body length. 9.2±20.1 mm.

Colour. Variable, see species descriptions.

Head. Dorsal surface asetose, but labrum sometimes with scattered setae. Outer margin of mandible variable. Labrum variable, sloping more or less strongly downward anteriad and posteriad from transverse, often non-carinate, elevated area, or virtually ¯at; anterior margin variable, straight to sinuate. Clypeus variable but mostly with feebly developed transverse, anterior carina; at posterior end either with one large, median tubercle, or bituberculate transverse carina, or two distinctly separated tubercles, or without ornamentation; antero-lateral angle of genae slightly to strongly raised. Frons without ornamentation, or with bituberculate or trituberculate transverse carina. Antennal club ovoid, slightly shorter than diameter of eye; glabrous area of basal segment half to two-thirds of exposed surface.

Pronotum. Variable (see species descriptions) but usually with carinate or tuberculate protuberance s and antero-median concavity/declivity; lateral margin entire or feebly crenulate.

Scutellum. Deltoid, lateral margin evenly curved (e.g. ®gure 26h).

Elytron. Anterior margin not upturned; striae moderately impressed and separated by two to four puncture diameters; intervals ¯at with variable punctation (see species descriptions); sutural stria terminating at scutellum in an arcuate line, second stria almost reaching elytral base.

Prosternum behind procoxae (®gure 24b). With median longitudinal carina.

Metasternum (®gures 24a, d). Disc more or less ¯at, process with feebly elevated, broadly and roundedly swollen lateral margin; longitudinal, median suture reaching (®gure 24a) or not reaching anterior declivity (®gure 24d); with steep, almost vertical decline from meso-metasternal suture to level of mesosternum.

Legs. Protibia of normal shape, non-dilated, ®ve- to seven-dentate. Protibial spur acuminate; elongate, longer than ®fth tarsomere. Protarsus with ®rst tarsomere shorter than ®fth tarsomere, about equally long as tarsomere 2, 3 or 4. Metafemur with punctation and setation in ventral view as in ®gure 24e. Metatibia in lateral view variable regarding shape and armature (see species descriptions). Metatarsus with setation on tarsomeres 2±4 variable, see species descriptions.

Underside. With moderately dense and long setation.

Male genitalia. Distinct aedeagal type with strongly sclerotized and apically modi®ed parameres.

Distribution. Throughout southern Africa.

Comments. Bolboceratex , with eight species is the largest of the southern African genera. The monotypic genus Bolbodius , also erected by Krikken (1984), is here synonymized with Bolboceratex . The most striking character shared by all eight species is the very distinct aedeagal type: the parameres are strongly sclerotized, usually elongate and laterally diverging, and apically modi®ed with small toothlike extensions. The internal sac has a pair of strongly sclerotized projections, interspeci®cally variable in shape and length. Usually only part of the projections is visible (arrows ®gure 28d) because the internal sac is normally retracted and hidden inside the tegmen. Apart from the unique aedeagal type, the species share the same shape of the scutellum, the prosternum behind the procoxae, the metasternum and the setation on the distal side of the metafemur.