Namibiobolbus heracles (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 : 1078-1080

Namibiobolbus heracles (Krikken)

(®gures 9a±d, 10g ±l, 12c, d, 14)

Bolboceroides heracles Krikken, 1977b: 339 , ®gures 1±6, 17±18.

Namibiobolbu s heracles (Krikken) : Krikken 1984: 37.

Description

Body length. 15.6±20.8 mm.

Colour. Dark brown.

Head. Labrum sloping downward from transverse carina in anterior third to quarter and posterior two-thirds to three-quarters; anterior margin very feebly sinuate (®gure 10g, i). Clypeus (®gures 10g, i, 12c, d) with steep, almost vertical incline from apex to well-developed and often strongly raised anterior transverse carina; anterior carina straight in frontal view, feebly curved in dorsal view; with short diagonal carina as in generic description; with well-developed lateral carina extended in a slightly arcuate line from endpoint of anterior carina to lateral margin above antennal insertion, at an angle continuing from there in a slightly arcuate but less raised line, not reaching posterior end of frons. Frons with strongly elevated median, feebly bi- (males, ®gures 10g, 12d) or feebly tri-tuberculate (females, ®gures 10i, 12c) transverse carina; carina between tubercles only very feebly depressed; surface from all sides gradually rising towards median carina; in females median carina as long as anterior clypeal carina and length of median carina occupying about half of total distance between lateral carinae (®gure 10i). Antennal club with glabrous area of basal segment two-thirds of exposed surface.

Pronotum. Males: with three large conical horns, one postero-medial and two antero-lateral, all three equidistant; major males with two large, deep, ovoid concavities between antero-lateral horns, and one smaller, deep, ovoid concavity each lateral to postero-medial horn (®gure 12d); minor males with the respective large and adjacent smaller concavity merging to one shallow concavity; 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 tubercle (horn) with very feebly indented midline but not reaching posterior pronotal margin. Females (®gure 12c): medially with transverse, slightly sinuate carina or swelling; from carina rather steeply declivous to anterior pronotal margin; antero-laterally 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, sometimes interspersed with large punctures of variable density; 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 1.3Ölength (®gure 10h); with minute and ®ne punctures, sometimes interspersed with large punctures of variable density near base.

Elytron. Striae moderately impressed, their punctures small and separated by two and a half to three and a half puncture diameters (®gure 10h); intervals with double punctation (approximately four ®ne and 13 minute punctures between two striae); elytral margin at apex distinctly subsinuate; pygidial apex in males bifurcate, with a circular incision.

Legs. Protibia ®ve-dentate.

Male genitalia. Aedeagus as in ®gure 10j±l.

Distribution (®gure 14). The species is only known from four localities in Namibia and one locality in Botswana.

Type material examined. HOLOTYPE, l`Farm Roidina [21.10S 16.04E], Omaruru distr. , SW Africa’ [hand-written]/`Holotype’ [printed on red label]/`Bolboceroide s heracles sp.n. ’ [handwriting Krikken]/`J. Krikken ms 19 76 [printed and hand-written] Holotype’ ( MNHN) ; PARATYPE, l`D.S.W. Afrika, Outjo [20.07S 16.09E], Westphal S.G.’ [hand-written on blue label]/` Paratype ’ [printed on label]/`Bolboceroide s heracles sp.n. ’ [handwriting Krikken]/`J.Krikke n ms 19 76 [printed and hand-written] Para type [hand-written and printed]’ ( ZMHB) .

Additional material examined (nine specimens). Botswana: 1m, Lake Ngami [ca 20.27S 22.51E], Collection E.Candeze ( ISNB) . Namibia: 1m, D.S.W. Afrika, Exc. Trotha S. ( ZMHB) ; 2 ll, 3mm, Mariental Distr., Hardapdam [24.31S 17.54E], 10± 14.iv.1972, Strydom & Jones ( TMSA) ; 1m, Hardap Dam, 24 17 Db, Marienthal , 19.iii.1979, V.B.Whitehead ( SAMC) ; 1m, Kamanjab [19.38S 14.51E], iii.1995, C. R. Owen ( COCS) .

Comments. The small number of specimens collected in comparison with Namibiobolbu s iphicles seems to indicate that Namibiobolbu s heracles is not a common species and possibly less widespread. The extent of variation in pronotal armature in males is presumably similar to Namibiobolbus iphicles but minor males with extremely reduced pronotal ornamentation have yet to be collected. The character states used in the key distinguish readily between the two species.