Bolbaoeer gigas, (Kolbe)

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 : 1065-1069

BolbaOEer gigas (Kolbe)

(®gures 2b, 4g ±j, 19g ±k, 21) Bolboceras gigas Kolbe, 1894: 167 (Descr. female); Boucomont, 1902: 4; 1912: 10; Paulian, 1941: 25; Petrovitz, 1969: 317, ®gure 5 (aedeagus, nec Kolbe).

BolbaOEer gigas (Kolbe) : Nikolajev, 1982: 37, ®gure 8; Krikken, 1984: 39.

Bolboceras maublanc i Paulian, 1941: 22, ®gure 48 (Descr. male); Petrovitz, 1969: 316 (Descr. females), ®gure 4 (aedeagus); Nikolajev, 1982: 37 (syn. of BolbaOEer gigas ).

Description male

Body length 21.5±25.9 mm (22 specimens). Colour light brown to dark brown, head and pronotum sometimes slightly darker. Outer margin of mandible very feebly sinuate (®gure 2b). Clypeus with strongly arcuate, transverse posterior carina; carina medially raised to feebly bifurcate horn; lateral endpoints of carina anteriad to antennal insertions but not reaching lateral clypeal margins; horn medially usually connected to anterior clypeal margin with short carina (®gure 2b). Frons distinctly depressed posterior to posterior clypeal carina. Antennal club with glabrous area of basal segment about one-half of exposed surface. Pronotum with anterior margin in dorsal view medially strongly bisinuate and in lateral view almost horizontally projecting over frons (®gure 2b); with outer pair of long, slightly inward curved horns along posterior margin in major males (®gure 4g), but protrusions more approximated, shorter and eventually reduced to small tubercles in minor males (®gure 4h, i); disc with ®ne, well-spaced punctures, these increasingly replaced by large, often conūent punctures towards sides, along posterior and sometimes along anterior margin of pronotum. Scutellum with surface coarsely punctate. Elytron with strial punctures separated by four to six puncture diameters; intervals with approximately ®ve to six punctures between two striae. Protibia mostly ®ve-, sometimes sixdentate. Protibial spur more or less as long as ®fth tarsomere, acuminate. Metatrochanter of unmodi®ed shape; with moderately long setae on entire surface, very dense in apical area, dense in other areas. Metafemur in ventral view in posterior third with line of densely spaced, long setae; otherwise with dense, long setation over entire surface, very dense in basal area and in basal half along posterior margin. Metatibia in lateral view elongate, only slightly broadening apically; with subapical carina lateral view with subapical carina bilobed or, more often, with only one welldeveloped lobe; with unmodi®ed spurs. Underside with sternite 4 unmodi®ed; posterior margin of sternite 5 medially roundedly emarginate (®gure 19g); posterior margin of sternite 6 medially deeply divided, the two lateral lobes fairly broad (®gure 19g) and apically densely setose; apex of pygidium unmodi®ed (not illustrated). Genitalia with aedeagus as in ®gure 19h±j; genital capsule apically with moderately long setation.

Description female

Body length 23.4±25.7 mm (21 specimens). Colour as in male. Outer margin of mandible rounded. Clypeus unarmed. Frons with distinctly raised bituberculate, transverse carina; carina positioned between eye-canthi; carina straight and distinctly shorter than anterior clypeal carina. Antennal club as in male. Pronotum with anterior margin medially feebly raised, in dorsal view arcuate; with transverse, distinctly carinate and strongly developed swelling at median portion of disc; carina in dorsal view bisinuate, in frontal view more or less straight and laterally arcuate (®gure 4j); swelling with a few ®ne punctures, interspersed with larger punctures of variable size; with large, mostly conūent punctures anterior, lateral and posterior to carinate swelling. Scutellum and elytron as in male. Protibia and protibial spur as in male. Metatrochanter of unmodi®ed shape; with dense, moderately long setae on entire surface. Metafemur in ventral view in posterior third with line of densely spaced, long setae; otherwise with dense, long setation over entire surface. Metatibia as in male. Underside with sternites 4, 5, 6 and pygidium unmodi®ed (®gure 19k).

Distribution (®gure 21). The species occurs in a broad band from the eastern parts in the D.R.C. through Uganda, Sudan, the Central African Republic, Cameroon westwards into Nigeria, Togo and Ivory Coast.

Type material examined. HOLOTYPE m, Bolboceras gigas Kolbe :` Togo, Bismarckbg [Bismarckburg, 08.11N 00.41E], Kling’ /`30.iv.89’ /`66127’ /` Bolboceras gigas n. sp. Kolbe’ [handwritten by Kolbe] /` gigas Kolbe *’ [handwritten by unknown curator] /`Type’ [printed on red label] (ZMHB); HOLOTYPE l[diss.], Bolboceras maublanci Paulian :`[ Central African Republic], Yalinga [06.33N 23.14E] (Oubangui), G. Le Testu’ /` Bolboceras maublanci n.sp. [handwritten by Paulian] det. R. Paulian 1937’ /`Type’ [black print on red label] (MNHN).

Additional material examined (41 specimens). Cameroon: 2 ll, Eseka [EseÂka, 03.39N 10.46E] ( MNHN) ; 1 l(MNHN), 1 l(TMSA), Cameroon; 1m, Tibati [06.28N 12.38E] ( ZMHB) ; 2mm, Galim, preÁs Tsabal-Mbabo [07.06N 12.29E] ( MRAC) . Central African Republic: 1 l[diss.], Tschad [incorrect, Central African Republic], Oubangui-Chari , Bangui [04.23N 18.37E] ( MNHN) ; 2 ll, 1m, Bangui [04.23N 18.37E] ( NHMG) ; 1m, Uamgebiet [Uuham Bende region], Bosum [Bozoum, 06.16N 16.22E] ( ZMHB) ; 1m, Bambari [05.40N 20.37E] ( EBCI) . D.R.C.: Allotype m, Bolboceras maublanci Paulian ,` Allotypus m’ /`Coll. Mus. Congo (Ex. Col. Le Moult)’ /`Congo belge, Katanga’ /` Allotypus’ /` Bolboceras maublanci Paul. m Petrovitz’ ( MRAC) ; 6 paratypes, Bolboceras maublanci Paulian : 1m,`MuseÂe du Congo, Aru [02.53N 30.50E], 18.vii.1931, H.J. Bredo’ ( MRAC) ; 1m,`MuseÂe du Congo, Stanleyville [Kisangani, 00.04N 25.18E] aÁ Kilo [Kilo, 01.49N 30.10E], L.Burgeon’ ( MRAC) ; 1m,`I.R.S. A.C. - Mus. Congo, Katanga: Kundelungu [mountains, NE of Lubumbashi], xii.1949, N. Leleup’ ( MRAC) ; 1m,`Coll. Mus. Congo, Kibali-Ituri: Aru [02.52N 30.51E], 1953, M. Winand’ ( MRAC) ; 1,`Coll. Mus. Congo, Ituri: Arara [not traced]- Aru , vi.1952, M. Winand’ ( NHMG) ; 1m,`MuseÂe du Congo, Haut UeleÂ: Tuku [02.24N 27.54E], iv.1919, P. Van den Plas’ ( NHMG) ; 1m, Congo belge, P.N.G., 16 April 1951, Miss H. de Saeger ( MRAC) ; 1, 1m, same data but: 1 January ± 15 April 1950 ( MRAC) ; 1m, same data but: 1 January ± 6 April 1950 ( MRAC) ; 2mm, same data but: 1 January ± 13 April 1950 ( MRAC) ; 1m, same data ( TMSA) ; 1, same data but: 1 January ± 15 September 1950 ( TMSA) ; 1, same data but: 1 January ± 31 March 1950 ( MRAC) ; 1, Congo belge, P.N.G., Haute Makpe [ Makpwe stream, unprecise] ( MRAC) ; 1 l[diss.], Bambesa [03.28N 25.43E] ( MRAC) ; 1, Haut-Ituri, Faradje [03.44N 29.43E] ( MRAC) ; 1 l[diss.], Uele, Tukpwo [Tukpo, 04.25N 25.52E] ( MRAC) ; 1 l[diss.], Congo belge, [illegible, Knou ] ( MRAC) ; 1 l[diss.], Terr. Libenge, vill. Malenge [06.17S 25.06E] ( MRAC) . Ivory Coast: 1, Foro-Foro [07.59N 05.03W], ( EBCI) ; 1m, Cote d’ Ivoire, Lamto ± Pacobo [not traced] ( MNHN) . Nigeria: 1 l[(diss.], Zaria Prov., Chikun [10.16N 07.06E] ( BMNH) . Sudan: 1, Juba [04.50N 05.03W] ( EBCI) . Uganda: 1 l[diss.], Uganda, N.W. Madi W. Nile, Metu hills [not traced] ( BMNH) . Untraced: 1 l[diss.], ReÂgion de Sassa ( MRAC) .

Comments. Bolboceras gigas was described by Kolbe (1894) from a single female. Paulian (1941) described B. maublanci from a single major male several decades later and did not realize that he was dealing with the matching opposite sex of B. gigas . This is due to a series of misidenti®cations of other BolbaOEer species. For example, Paulian (1941: 25) redescribed the female of B. gigas and for the ®rst time added a description of several that he believed to be previously undescribed matching males. This series of males, according to Paulian (1941: 26), was already identi®ed, with doubt though, as B. gigas by Boucomont. We have found one male specimen in BMNH with a label attached`? gigas Kolbe , det. Boucomont’. This specimen belongs to the later described B. splendidus and agrees with the habitus illustration of `B. gigas ’ in Paulian (1941: ®gure 10). Paulian (1941: ®gure 24) also illustrated the aedeagus of a `B. gigas ’ that corresponds with the aedeagus of a true B. gigas but not with B. splendidus . Furthermore, Paulian (1941: 24) incorrectly synonymized B. bidenticollis with B. princeps and illustrated the habitus of a B. bidenticollis as a B. princeps male ( Paulian, 1941: ®gure 16). The confusion continues with Petrovitz (1969) who described the females of B. maublanci but did not notice that they are identical to the female holotype of B. gigas . The identi®cation key to the males of BolbaOEer species is accompanied by the illustration of a B. bidenticollis aedeagus instead of a B. princeps aedeagus ( Petrovitz, 1969: ®gure 6) and the illustration of a B. princeps aedeagus instead of a B. gigas aedeagus ( Petrovitz, 1969: ®gure 5). Nikolajev discovered these errors and correctly placed B. maublanci in synonymy with B. gigas , B. gigas sensu Paulian nec Kolbe in synonymy with B. splendidus , and B. gigas sensu Petrovitz nec Kolbe in synonymy with B. princeps . Nikolajev was, however, unsure about the taxonomic status of B. bidenticollis , not having seen the type material. Instead he described B. petrovitzi ( Nikolajev 1982: 37)Ðin the present paper clearly con®rmed a synonym of B. bidenticollis Ðand placed B. princeps sensu Paulian nec Kolbe and B. princeps sensu Petrovitz nec Kolbe in synonymy with B. petrovitzi .

Petrovitz (1969) designated an allotype and six paratypes when describing the opposite sex of Bolboceras maublanci Paulian. Similar to the case of B. tenuelimbatus , these specimens have no type standing and are listed under`Additional material examined’. For the allotype all label data are cited verbatim, for the paratypes only locality labels are cited verbatim.

The correct association of the male holotype of B. maublanci and the subsequently described females with the female holotype of B. gigas is veri®ed by two males and one female with identical label data, collected in the Central African Republic, and in addition by three males and six females collected in the D.R.C. by the same collector, on the same day in the case of two specimens, and during the same period of time in the case of the remaining four specimens. Males of B. gigas are very easily identi®ed by their clypeal armature, the median portion of the anterior pronotal margin almost horizontally projecting over the frons in lateral view, the modi®ed shape of sternites 5 and 6, the unmodi®ed shape of the pygidium and the shape of the aedeagus. Females of B. gigas can be separated from females of all the other congeneric species by the lack of any modi®cations on the abdominal sternites and the pygidium (®gure 19k). Females of B. gigas are most similar to females of B. princeps but with some experience it is possible to depict a few subtle diOEerences: the metatrochanter in females of B. gigas is setose over its entire surface while in B. princeps females the metatrochanter is setose only in the basal third and along the posterior margin but asetose on the remaining surface. Similar to that, the metafemur in B. gigas females is in ventral view densely setose over the entire surface while it is partially almost asetose in B. princeps females. Another slight diOEerence can be found in the shape of the pronotal, transverse swelling which in B. gigas females is more pronounced but in frontal view medially constricted and a little depressed. In dorsal view the curvature is distinctly bisinuate because the lateral parts of the swelling are positioned at a slight angle to each other. In females of B. princeps , on the other hand, the swelling is medially less constricted in frontal view, usually not depressed and in dorsal view the lateral parts of the swelling are positioned in an almost straight line. Lastly, a feeble, arcuate emargination at the apex of the pygidium may be present in females of B. princeps (®gure 19f) but no modi®cation is found in females of B. gigas . However, since the pygidium is very often retracted and hidden under the elytra, this character state is usually concealed and its consistency cannot be con®rmed. DiOEerences between B. gigas and B. nikolajevi females are essentially the same as between B. princeps and B. nikolajevi females. In addition to those, there is a distinct diOEerence in size, with the body length of B. nikolajevi females ranging between 19.2 and 20.4 mm but ranging between 23.4 and 25.7 mm in B. gigas females. Furthermore, the same diOEerence between B. gigas and B. princeps in pronotal armature (shape of transverse swelling) is found between B. gigas and B. nikolajevi .

The obvious similarities of B. gigas males with males of B. princeps and B. nikolajevi , in particular with regard to sternal and pygidial modi®cations (compare illustrations), clearly place B. gigas in the B. princeps species-group.