Namibiobolbus helgae, 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 : 1080-1081

Namibiobolbus helgae spec. nov.

(®gures 9a±d, 11a±j, 13a, b, 14)

Description

Body length. 13.4±19.7 mm.

Colour. Mid-brown to dark brown.

Head. Labrum (®gure 11a, c) sloping downward from distinct transverse carina in anterior third and posterior two-thirds; anterior margin feebly sinuate. Clypeus (®gures 11a, c, 13a, b) with steep, almost vertical incline from apex to well-developed and strongly raised anterior transverse carina; anterior carina in frontal view slightly sinuate (®gure 11d) or notched in the middle (®gure 11e), moderately arcuate in dorsal view; with well-developed lateral carina extended in a straight line from endpoint of anterior carina to lateral margin above antennal insertion, at an angle continuing from there in a feebly arcuate, feebly developed line, extending not beyond anterior half of frons; with well-de®ned diagonal short carina as in generic description. Frons in males usually without armature, sometimes with small median tubercle (®gures 11a, 13b) or short transverse carina; in females with strongly elevated feebly trituberculate median transverse carina (®gures 11c, 13a); carina between tubercles only very feebly depressed; surface more or less ¯at in males, gradually rising towards median carina from all sides in females; in females median carina distinctly longer than anterior clypeal carina and length of median carina occupying about three-®fths of total distance between lateral carinae (®gure 13a). Antennal club with glabrous area of basal segment slightly more than half of exposed surface.

Pronotum. Males (®gure 13b): with three protuberances, one postero-medial knob with narrow base and broad apex (®gure 11f, g) and two antero-lateral protuberances (®gure 11f, g), ranging from small conical tubercles (minor males) to large conical horns (major males), all three equidistant; in major males with large, deep, ovoid concavity posteriorly to each antero-lateral horn and anteriorly to posteromedian protuberance (®gure 13b); in minor males concavities smaller and more shallow to obsolete; deepest parts of concavities with minute punctation interspersed with some ®ne punctures, on edges with some large punctures, the latter becoming very dense on the protuberances; minute punctation disappearing and replaced by ®ne punctation and increasingly dense and partly conūent, large punctation towards sides of pronotum; posterior to median knob with very feebly indented midline but not reaching posterior pronotal margin. Females (®gure 13a): medially with transverse, strongly developed sinuate carina; carina slightly depressed at midline; steeply declivous from carina to anterior pronotal margin; antero-laterall y with one conical tubercle each; surface between carina and tubercles with minute and ®ne punctation interspersed with scattered large punctures; posterior surface with minute and ®ne punctation, interspersed with large punctures; minute and ®ne punctation replaced gradually by increasingly dense and often conūent large punctation towards median transverse carina and lateral pronotal sides; in posterior half with obsolete or feebly indented midline, neither reaching transverse carina nor posterior pronotal margin; lateral margin entire.

Scutellum. Basal width about 1.23Ölength (®gure 11b); with minute and ®ne punctures.

Elytron. Striae moderately impressed, their punctures small and separated by three to four puncture diameters (®gure 11b); intervals with double punctation (approximately four ®ne and eight minute punctures between two striae); elytral margin at apex feebly subsinuate; pygidial apex in males unmodi®ed, rounded.

Legs. Protibia six-, sometimes ®ve-dentate.

Male genitalia. Aedeagus as in ®gure 11h±j.

Distribution (®gure 14). The species is only known from two localities in the Karoo (Northern Cape Province, South Africa) and two localities in Namibia.

Type material examined. HOLOTYPE: l` South Africa, Northern Cape Province, Brandvlei , 30.27S 20.29E, 12± 14.iv.1997, leg. C.R.Owen’ ( TMSA); 99 PARATYPES: 5 ll, 11mm ( TMSA) , 2 ll, 4mm (UPSA), 2 ll, 4mm (SMWN), 2 ll, 4mm (ZMHB), 2 ll, 4mm (MRAC), 2 ll, 4mm (MNHN), 19 ll, 20mm (COCS), 1, l 2mm (SAMC), 1, l 1m ( TMPT) , same data; 2 ll, 4mm, same data but: leg. A. Joubert ( AJCS) ; 1m, same data as holotype but: 30.iii.1997, leg. C. R. Owen ( COCS) ; 1, l 1m,` South Africa, 6 km NW Fraserberg [31.51S 21.28E], C.P., 25.iii.1974, H. D. Brown ( SANC) .

Additional material examined (two specimens). Namibia: 1m, Asab [25.28S 17.57E], xii.1925, J. S. Brown ( SAMC) ; 1m, Barby Farm [SE 25 16 Dc], 25 mls W. Helmeringhausen, 17± 18.i.1972, Southern African Exp. B.M. 1972-1, at light ( BMNH) .

Etymology. Named after Mrs Helga Owen, spouse of the collector C. R. Owen.

Comments. The aedeagal type, cephalic and pronotal armature, metasternum and other characters clearly place the new species with Namibiobolbus . The posteromedial knob on the pronotum easily distinguishes the males of Namibiobolbus helgae spec. nov. from males of the other two species, although in minor males the knob can be greatly reduced. The females of Namibiobolbus helgae and Namibiobolbus iphicles are very similar and can only be separated by their cephalic armature (see key). Because of the di culties to safely identify the females, we excluded females from above type series that were collected without males.