Bolboceratex holmi, Gussmann S. M. & Scholtz, 2000

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 : 1120-1121

Bolboceratex holmi spec. nov.

(®gures 24a±c, e, 27c, d, 29f±j, 33b, 35)

Description

Body length. 16.6±20.1 mm.

Colour. Mid-brown.

Head. Dorsal surface asetose. Outer margin of mandible (®gures 27c, 33b) rounded. Labrum (®gure 27c) asetose; declivous in anterior third and posterior twothirds, transverse carina obsolete; anterior margin distinctly sinuate. Clypeus (®gure 27c) sloping upward to apex of feebly developed to strongly raised transverse anterior carina; lateral carina anteriorly feebly developed but raised and distinct above antennal insertion, continuing from there posteriorly in a straight and then arcuate line to almost posterior end of frons; antero-lateral angle of genae sharply raised; with posterior transverse bituberculate carina, carina U-shaped between tubercles; carina laterally terminating with tubercles, not joining lateral clypeal margin. Frons with most of its surface slightly depressed. Antennal club with glabrous area of basal segment about half of exposed surface.

Pronotum (®gures 29i, j, 33b). With large concavity occupying anterior median two-thirds of pronotum; concavity narrowed to posterior U- or V-shaped end (®gure 33b), sides steepest at posterior end; posteriorly with obsolete midline; each endpoint of the`U’ or`V’ feebly tuberculate; concavity with very ®ne punctures, interspersed with large punctures, the latter becoming increasingly more densely spacedÐbut not deeperÐand often conūent towards sides; concavity at its widest point about as wide as frons between eyes; lateral margin entire.

Scutellum (®gure 27d). Basal width about 1.5Ölength; with very ®ne punctures, interspersed with moderately sized punctures.

Elytron. Striae moderately impressed, their punctures separated by two to three puncture diameters (®gure 27d); intervals with double punctation (with approximately four to ®ve ®ne and 20 minute punctures between two striae).

Metasternum. As in generic description but length of longitudinal suture variable, either reaching meso-metasternal suture (®gure 24a) or not reaching it (®gure 24d).

Legs. Protibia ®ve-dentate. Metatibia in lateral view elongate, only feebly broadening apically; with subapical carina distinctly bilobed; with toothlike projections arranged in two rows above subapical carina. Metatarsus lacking subapical setae on tarsomeres 2±4.

Male genitalia (®gure 29f±h). Aedeagus very large relative to the body size.

Distribution (®gure 35). The species is known only from its type locality.

Type material examined. HOLOTYPE: l` South Africa, Northern Cape Province, Brandvlei , 30.27S 20.29E, 12± 14.iv.1997, leg. C. R. Owen’ ( TMSA); 13 PARATYPES: 1m ( TMSA) , 1, l 1m ( UPSA) , 2 ll, 2mm (COCS), 1, l 1m ( SMWN) , same data as holotype; 2 ll , 1m, same data but: leg. A. Joubert ( AJCS) ; 1, l same data but: 30.iii.1997 ( COCS) .

Etymology. The species is named after emeritus Prof. Erik Holm who did most of the habitus illustrations in this paper.

Comments. In external morphology, Bolboceratex holmi agrees with the general generic characteristics and is thus justi®ably placed in Bolboceratex . Sexual dimorphism is absent and intraspeci®c variability minimal.

The new species can only be confused with the sympatric Bolboceratex jouberti . Reliable external morphological characters to distinguish the two species are the outer margin of the mandible, i.e. rounded in the latter but distinctly sinuate in the former species, the metatibia in lateral view which is elongate and only feebly broadening towards apex in the latter species but distinctly broadening in the former species. The metatibial armature also diOEers between the two species. Figures 29a ±c, 29f±h clearly illustrate the diOEerences of the aedeagi in size and structure. While Bolboceratex jouberti ’s genitalia have the more typical shape for the genus, Bolboceratex holmi has shortened parameres. The aedeagus of Bolboceratex holmi is the most modi®ed within the genus but does share the strongly sclerotized parameres, armed with toothlike projections, with its congeneric species. A pair of strongly sclerotized, elongate projections as part of the internal sac is also present.

Figures

FIG. 29. Bolboceratex jouberti: aedeagus, ventral (a), dorsal (b), lateral view (c); pronotum male, lateral (d) and frontal view (e). B. holmi: aedeagus, ventral (f), dorsal (g), lateral view (h); pronotum male, lateral (i) and frontal view (j).