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
Meridiobolbus
Krikken
(®gures 9a±e, 15a±f, 16a±i, 18a, b, 19, 20, 24e)
Meridiobolbus
Krikken, 1984: 38
.
Type
species:
Bolboceras hebes
PeÂringuey, 1908
, by original designation.
Description
Body length
.
9.5±17.7 mm
.
Colour
. Light to dark brown.
Head
.
Dorsal surface
asetose.
Outer margin of mandible
rounded and often anteriorly more strongly curved inward.
Labrum
declivous anteriad and posteriad from feebly developed, slightly arcuate, to obsolete transverse carina; anterior margin distinctly sinuate.
Clypeus
with feebly to strongly elevated transverse anterior carina; with well-de®ned, short diagonal, posteriorly steeply inclined carina, the latter connecting the antero-latera l marginal angle and the respective endpoint of the transverse anterior carina (e.g. ®gure 15c); 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 15c).
Frons
with strongly elevated bituberculate or trituberculate transverse carina positioned between eye-canthi or slightly posteriad to eye-canthus; antero-lateral angle of eye-canthus distinctly raised.
Antennal club
ovoid, slightly shorter than diameter of eye; glabrous area of basal segment more or less half of exposed surface.
FIG. 15.
Meridiobolbus faustus
: head dorsal view, male or female (a); scutellum and strial punctures (b).
M. quinquedens
: head dorsal view, male or female (c); scutellum and strial punctures (d).
M. natalensis
: head male holotype, dorsal view (e); scutellum and strial punctures (f).
FIG. 16.
Meridiobolbus faustus
: aedeagus, ventral (a), dorsal (b), lateral view (c);
M. quinquedens
: aedeagus, ventral (d), dorsal (e), lateral view (f);
M. natalensis
: aedeagus, ventral (g), dorsal (h), lateral view (I).
Pronotum
. With four protuberances, variably positioned (see species descriptions); with large and ®ne punctation; lateral margin entire.
Scutellum
. Deltoid; basal width about 1.25±1.44Ölength; lateral margin medially abruptly curved (e.g. ®gure 15b); variably punctate (see species descriptions).
Elytron
. Anterior margin not upturned; striae moderately to strongly impressed, their punctures small and separated by two to four puncture diameters; intervals ¯at, with single or 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. 17.
Meridiobolbus quinquedens
: major male (a), minor male or female (b).
Prosternum behind procoxae
(®gure 9b, c). As in
Namibiobolbus
, i.e. with protruding median, longitudinal carina near base, sometimes with additional small tubercle at apex.
Metasternum
(®gure 9a). As in
Namibiobolbus
, i.e. 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- or rarely six-dentate.
Protibial spur
acuminate; elongate, longer than ®fth tarsomere.
Protarsus
with ®rst tarsomere shorter than ®fth tarsomere, about equally long as tarsomere 2, 3 or 4.
Metafemur
with punctation and setation of ventral side as in ®gure 9d or 24e.
Metatibia
in lateral view variable regarding shape and armature (see species descriptions).
Metatarsus
lacking subapical setae on tarsomeres 2±4.
FIG. 18.
Meridiobolbus faustus
: male or female (a).
M. natalensis
: male holotype (b).
Underside
. With moderately dense and long setation.
Male genitalia
. Compact aedeagal
type
with lobelike projections on parameres.
Distribution
(®gures 19, 20). Eastern
Namibia
,
Botswana
, northern and central parts of
South Africa
, and
Zimbabwe
.
Comments
. Of the six southern African genera,
Meridiobolbus
is the least well de®ned. It is closest to
Namibiobolbus
with which it shares a number of characters. The lack of strong sexual dimorphism, the pronotum of males with four versus three protrusions and the aedeagal
type
are, however, considered su cient to maintain
Meridiobolbus
as a separate genus.