Systematic revision of endemic southern African genera of Bolboceratinae (Coleoptera: Scarabaeoidea: Bolboceratidae)
Author
Gussmann S. M.
Author
Scholtz, C. H.
text
Journal of Natural History
2000
2000-12-31
34
1045
1123
journal article
10.1080/00222930050020122
1464-5262
4747979
Namibiobolbus
Krikken
(®gures 9a±d, 10a±l, 11a±j, 12a±d, 13a, b, 14)
Namibiobolbus
Krikken, 1984: 37
.
Type
species:
Bolboceras iphicles
Kolbe, 1907
, by original designation.
Description
Body length
.
10.5±20.8 mm
.
Colour
. Light to dark brown.
FIG. 9.
Namibiobolbus
spp.
and
Meridiobolbus
spp.
: metasternum (a); posterior end of prosternum, frontal (b), lateral view (c).
Namibiobolbus
spp.
and
Meridiobolbus quinquedens
: metafemur, ventral view (d).
Head
.
Dorsal surface
asetose.
Outer margin of mandible
rounded but anteriorly more strongly curved inward.
Labrum
declivous anteriad and posteriad from distinctly elevated slightly arcuate, transverse carina; anterior margin feebly sinuate.
Clypeus
with feebly to strongly elevated transverse anterior carina; with well-de®ned, short diagonal, posteriorly steeply inclined carina, the latter connecting the anterolateral marginal angle and the respective endpoint of the transverse anterior carina (e.g. arrows ®gure
10g
); with distinct lateral carina from endpoint of anterior carina extending to above antennal insertion, from there extending posteriorly in a slightly curved line past eye-canthus on frons, sometimes reaching posterior end of frons (e.g. ®gure 10a).
Frons
males: with one tubercle, or a strongly elevated bituberculate transverse carina positioned between eye-canthi, or without ornamentation; females: with a strongly elevated trituberculate transverse carina in line with postero-lateral angle of eye-canthus (e.g. ®gure 10c); both sexes: antero-lateral angle of eye-canthus not raised or only feebly raised.
Antennal club
ovoid, slightly shorter than diameter of eye; glabrous area of basal segment half to two-thirds of exposed surface.
Pronotum
. Males: with three protuberances (one median, two lateral) and two to four deep concavities; females: with two small antero-lateral protuberances and one antero-medial transverse carina (can be reduced to bituberculate carina or single protuberance); lateral margin entire.
Scutellum
. Deltoid; basal width about 1.2±1.4Ölength; lateral margin medially abruptly curved (e.g. arrows ®gure 10b); with ®ne punctures.
Elytron
. Anterior margin not upturned; striae lightly to moderately impressed, their punctures small to very small and separated by two to four and a half puncture diameters; intervals ¯at, with double punctation (®ne and minute punctures); sutural stria terminating at scutellum in a straight line, second stria obsolete near scutellum, neither reaching scutellum nor elytral base.
FIG. 10.
Namibiobolbu s
iphicles
: head dorsal view, male (a) and female (c); scutellum and strial punctures (b); aedeagus, ventral (d), dorsal (e), lateral view (f).
N. heracles
: head dorsal view, male (g) and female (i); scutellum and strial punctures (h); aedeagus, ventral (j), dorsal (k), lateral view (l).
FIG. 11.
Namibiobolbu s
helgae
: head dorsal view, male (a) and female (c); scutellum and strial punctures (b); variation clypeus male, frontal view (d, e); pronotum major male, lateral (f) and frontal view (g); aedeagus, ventral (h), dorsal (i), lateral view (j).
Prosternum behind procoxae
(®gure 9b, c). With protruding median, longitudinal carina near base, sometimes with additional small tubercle at apex.
FIG. 12.
Namibiobolbu s
iphicles
: female (a), major male (b).
N. heracles
: female (c), major male (d).
Metasternum
(®gure 9a). Disc more or less ¯at, process medially depressed and with upturned, ridged lateral margins; with longitudinal, median suture reaching meso-metasternal suture; meso-metasternal suture present at the top of the steep, sloping anterior declivity.
Legs
.
Protibia
of normal shape, non-dilated, ®ve-dentate (rarely six-dentate).
Protibial spur
acuminate; elongate, longer than ®fth tarsomere.
Protarsus
with ®rst tarsomere shorter than ®fth tarsomere, about as long as tarsomere 2, 3 or 4.
Metafemur
with punctation and setation of ventral side as in ®gure 9d.
Metatibia
in lateral view elongate, only slightly broadening apically; with subapical carina feebly to strongly bilobed; with toothlike projections arranged in two rows above subapical carina.
Metatarsus
lacking subapical setae on tarsomeres 2±4.
FIG. 13.
Namibiobolbu s
helgae
: female (a), major male (b).
FIG. 14. Distributional records:
Namibiobolbu s
iphicles
E
;
N. heracles
_
;
N. helgae
H
. Distributional
overlap:
N. iphicles
and
N. heracles
+
.
Underside
. With moderately dense and long setation.
Male genitalia
. Compact and broad aedeagal
type
with parameres consisting of feebly sclerotized, folded membranes.
Distribution
(®gure 14). Southern MocËambique,
Namibia
, north-western and north-eastern parts of
South Africa
, and probably
Botswana
.
Comments
.
Krikken (1977b)
placed
Bolboceras iphicles
Kolbe
and the new species
heracles
in the genus
Bolboceroides
. Later (
Krikken, 1984
) he transferred both species into the newly erected genus
Namibiobolbus
. Thus the
type
species
Bolboceras capense
PeÂringuey
remained the only species in the genus
Bolboceroides
. This latest classi®cation by Krikken is accepted here as there are numerous diOEerences between
Namibiobolbus
and
Bolboceroides
. The latter is in fact more similar to
Bolboceratex
(treated below), whereas
Namibiobolbus
stands closer to
Meridiobolbus
(treated below).
One new species is added here to the genus
Namibiobolbus
.
The combination of the character states mentioned in the generic key as well as a distinct aedeagal
type
identify the genus
Namibiobolbus
su ciently. Sexual dimorphism is very pronounced in cephalic and pronotal armature but the females of two of the three species are almost indistinguishable.