Bolbaoeer tenuelimbatus, (Quedenfeldt)

Gussmann, S. M. V. & Scholtz, C. H., 2001, Systematic revision of the Afrotropical genus BolbaOEer Vulcano, Martinez and Pereira (Coleoptera: Scarabaeoidea: Bolboceratidae: Bolboceratinae), with descriptions of eight new species, Journal of Natural History 35 (7), pp. 1013-1084 : 1043-1045

BolbaOEer tenuelimbatus (Quedenfeldt)

(®gures 2e, 3g ±i, 9a±f, 11)

Bolboceras tenuelimbatus Quedenfeldt, 1884: 294 (Descr. female); Kolbe, 1889: 124 (Descr. male); Boucomont, 1902: 6; 1912: 14; Paulian, 1941: 21 ( Bolboceras tenuelimbatum ); Ferreira, 1965: 1227 ( Bolboceras tenuelimbatum, Cat. ); Petrovitz, 1969: 319 ( Bolboceras tenuelimbatum, Redescr. male).

BolbaOEer tenuelimbatum (Quedenfeldt) : Nikolajev, 1982: 39, ®gure 9; Krikken, 1984: 39.

Description male

Body length 18.2±23.1 mm (33 specimens). Colour light brown to dark brown, head and pronotum often slightly darker. Outer margin of mandible strongly sinuate. Clypeus with feebly to strongly developed, bituberculate transverse posterior carina; tubercles in line with antennal insertions; length of posterior carina variable, from much shorter than anterior carina to almost as long as anterior carina; posterior carina sometimes reduced to two small swellings. Frons feebly depressed posterior to posterior clypeal carina. Antennal club with glabrous area of basal segment about one-third to less than one-half of exposed surface. Pronotum with anterior margin medially produced into arcuate horn of variable length with distinctly bifurcate apex (®gure 3g, h); on either side of midline with elongate, non-carinate swelling parallel to posterior margin in major males; swellings obsolete in minor males; no horns / tubercles present along posterior margin; disc with ®ne well-spaced punctures, these punctures increasingly replaced by large, often conūent punctures postero-laterally. Scutellum with surface moderately punctate. Elytron with strial punctures separated by four to ®ve puncture diameters; intervals with approximately four to ®ve punctures between two striae. Protibia six-, rarely ®ve- or seven-dentate. Protibial spur slightly longer than ®fth tarsomere, acuminate. Metatrochanter of unmodi®ed shape; entire surface with moderately long and fairly dense setation except for asetose apex. Metafemur in ventral view in posterior third with line of densely spaced moderately long and long setae; with fairly dense, long setation in anterior third and in apical area; with fairly dense, moderately long setation in basal area and along posterior margin; remaining areas with some isolated setae. Metatibia in lateral view with subapical carina bilobed, sometimes trilobed; with unmodi®ed spurs. Underside with sternites 4 and 5 unmodi®ed; posterior margin of sternite 6 broadly and roundedly emarginate (®gure 9b); apex of pygidium feebly bisinuate (®gure 9a). Genitalia with aedeagus as in ®gure 9c±e; genital capsule apically with moderately long setation.

Description female

Body length 19.9±24.0 mm (23 specimens). Colour as in male. Outer margin of mandible with sinuate curvature slightly less pronounced than in male (®gure 2e). Frons (®gure 2e) with strongly raised bituberculate, transverse carina between eyecanthi; carina straight and as long as anterior clypeal carina. Antennal club as in male. Pronotum with anterior margin in frontal view medially very feebly raised and very feebly bisinuate, in dorsal view arcuate (®gure 2e); transverse carina medially and laterally obsolete, dividing the swelling at median portion of disc into two strongly protruding tuberculate swellings (®gure 3i); swellings with ®ne, well-spaced punctures, towards anterior margin interspersed with some large punctures; with large, mostly conūent punctures lateral and posterior to swellings. Scutellum and elytron as in male. Protibia and protibial spur as in male. Metatrochanter of unmodi- ®ed shape; surface in basal third and along posterior margin with moderately long and fairly dense setation, remaining surface with a few scattered setae or asetose. Metafemur in ventral view in posterior third with line of densely spaced moderately long and long setae; with sparser, moderately long setation in anterior third and apical area, in basal area and along posterior margin; remaining areas asetose. Metatibia as in male. Underside with sternites unmodi®ed; apex of pygidium broadly bisinuate (®gure 9f).

Distribution (®gure 11). The species is found in Congo, Gabon, the southern parts of the D.R.C. and the northern half of Angola.

Type material examined. HOLOTYPE m:`Quango Strom, Major v. Mechow’ /`m’ /`Ex Musaeo Quedenfeldt’ /` tenuelimbatus Quf *’ [possibly handwritten by Quedenfeldt] /`Type’ [printed on red label] /`Museum Paris ex Coll. R.Oberthur’ [printed on blue label] ( MNHN).

Additional material examined (56 specimens). Angola: 1,`[SaÄo] Salvador [Angola, M’ banza Congo, 06.18S 14.16E], Kongo, R.BuÈttner’ [printed on green label] /`64155’ /` Bolboceras tenuelimbatus Quedf. ’ [handwritten by Kolbe] /` tenuelimbatum Qued. Kolbe *’ [handwritten by unknown curator on blue label] /`Type’ [printed on red label] /`Zool. Mus. Berlin’ (ZMHB); 2 ll, Kongo, Salvador, R. BuÈttner (ZMHB); 1, Province Moxico, env. Luso [11.47S 19.52E], R.P.P. Dias (MNHN); 1, Benguela [12.35S 13.35E] (MNHN). Congo: 1, 2mm, DieÃleà [DzieÂle stream, taken at 01.41S 14.45E], 1886, de Brazza (MNHN); 1, Congo francËais, Leug [y]o [not traced], 28 May 1897, Hermans (ISNB); 1m, Congo, 1893, Thollon (MNHN). D.R.C.: 2 ll[1 diss.], 2mm, Kwango [Prov., taken at 12.00S 18.15E], 1923, R.P. Biebuyck (ISNB); 3 ll[diss.], Katanga, Kinda [09.18S 25.04E], 1926, F.G. Overlaet (ISNB); 1 l[diss.], 1m, same data (TMSA); 1 l[diss.], 1m, Kasai, Lusambo [04.58S 23.27E], J. Gillet (ISNB); 1, 1m, Kasai, Galli-Koko [Galikoko, 04.58S 21.15E], R. Charlier (MRAC); 1m, LeÂopoldville [Kinshasa, 04.18S 15.18E], 1942, R. Fiasse (MRAC); 1, LeÂopoldville, March± April 1912, Dr Christy (MRAC); 1m, LeÂopoldville, November 1913, Dr A. Dubois (MRAC); 2 ll, 1m, Moyen Kwilu, Leverville [04.50S 18.44E], P. Vanderijst (MRAC); 1, Kabambare [04.40S 27.41E], 1933, Admiral Lynes (MRAC); 1m, Katanga, (Bas) Penge [05.31S 24.34], January 1926, Ch. Seydel (MRAC); 1 l[diss.], Kwango, Djuma [04.14S 18.21E], April / May 1953, R.P.LeÂta (MRAC); 1 l[diss.], Kwango, Terr. Feshi [06.08S 18.12E], April 1959, Leleup (MRAC); 1 l[diss.], Bas Congo, Kisantu [two localities close to each other, taken at 05.07S 15.05E], 29± 30 November 1952, P. Basilewsky (MRAC); 1 l[diss.], 1m, Mayidi [05.11S 15.09E], 1942, ReÂv. P. Van Eyen (MRAC); 1m, Katanga, Luashi [10.56S 23.37E], March 1936, Freyne (MRAC); 1 l[diss.], Lualaba, Kamina [08.46S 25.00E], 9 February 1955, M. Ledieu (MRAC); 1m, Bena Leka [Bena-Leka, 05.08S 22.10E], April 1956, N. Martens (MRAC); 1, Bandundu [03.19S 17.22E], Tumikia [not traced], September 1988, J. Hubin (EBCI); 1m, Kwango, Kiniati-Yasa [too vague, Kiniati 05.19S 12.58E, Yasa 04.37S 17.59E], December 1951 / January 1952, R.P. Ruelle (MRAC); 1m, Kasai, Thisika [not traced], 2 November 1921, Dr H. Schouteden (MRAC); 1, Kasai, Sankuru [Riv., too vague], January 1928, Don de Mme Trolli (MRAC); 1, Mukishi [several localities by that name] (K.186-B.C.K.), February 1928, A. Bequest (MRAC); 1, [illegible], 26 December 1911, D. Roshain (MRAC); 1, 1m, Beni Bendi [not traced], Sankuru, January 1895, L. Cloetens (ISNB); 1, Congo, Kasai (GCCI); 1m, Kassai, 1887 ±88, Cap. Thys (ISNB); 1, Congo belge, J. Gillet (ISNB); 1, 45 km da Kintele [too vague], October 1986, Devatour (EBCI). Gabon: 1, Afrique Occid. [Gabon], Ogowe [Ogooue stream, taken at 00.49S 09.00E], 1890, L. Gazengel (MNHN); 1, 1m, Gabon, J. Carradot (ISNB). Untraced: 1, Assam, Cadar (ZMHB).

Comments. Bolboceras tenuelimbatum was described by Quedenfeldt (1884) from a single female specimen. A few years later, Kolbe (1889) discovered the matching opposite sex in a series consisting of two females and one major male that were all collected together. He consequently described the male and a type label has been attached to the specimen. The latter has, however, no type standing and is therefore listed here, with its label data cited verbatim, under`Additional material examined’.

The most striking features of male B. tenuelimbatus are the lack of any tubercles / horns along the posterior pronotal margin and the presence of an apically bifurcate, arcuate horn, medially produced from the anterior margin. The strongly sinuate outer margin of the mandible is an additional character state that distinguishes male but also female B. tenuelimbatus from congeneric species. Modi®cations on abdominal sternites and pygidium are minor in males and females but are species speci®c. Female B. tenuelimbatus are furthermore recognized by their pronotal armature: they possess a pair of distinctly protruding tuberculate swellings at the median portion of the disc, while females of other species possess a continuous transverse, medially constricted, carinate swelling.