Dorylus (Dorylus) helvolus (Linnaeus)
Type locality South Africa (Vespa helvolus,
Linnaeus, 1764: 412, male; illustrated by Coquebert, 1798, Plate
XVI); junior synonyms dorylus (Mutilla dorylus,Lamarck,
1817: 101, male; minimal description, apparently simply reporting
the Linnaeus description but using a different name) from "Africa",
europaea (Typhlopone europaea, Roger, 1859: 248,
illustrated, worker [page unavailable on HNS]) from Italy?),
planifrons (Mayr, 1865: 74, male, illustrated) from South
Africa, and punctata (Typhlopone punctata,
F Smith, 1858b: 112, worker) from South Africa; subspecies
pretoriae (Arnold, 1946: 59, all forms, illustrated) from
South Africa; all forms described (see Bolton, 1995).

Linnaeus's (1764) brief description of the male is at
;
Lepeletier de Saint-Fargeau (1835: 213) gave a description, this
is at .
Emery's (1895j: 714) gave a full, illustrated description; this is
at ;
with the illustrations on
.
Smith's (1858b) brief description of punctata is at
;
Mayr's (1865) illustrated description of the planifrons
male is at
;
Arnold's (1946) illustrated description of pretoriae is at
.
Wheeler (1922) listed it also from Togo (Bismarckburg, Büttner),
Nigeria (Agege by W.A. Lamborn); plus many mostly southern
Africa records. |
Arnold
(1915: 116) had the following description and the image (right,
apparently of a minor worker) -
"Soldier or worker maxima - TL 8 mm; castaneous, mandibles
and anterior portion of head and apical segments of gaster,
darker. Legs very scantily pubescent, funiculus moderately
pubescent, a few long hairs on the petiole and abdominal segments.
Whole body, except the posterior face of the node and the
funiculus, very shining, evenly and distinctly punctured. The
punctures are larger and deeper on the head and thorax, shallower
and smaller on the petiole and gaster. The petiole is
reticulate-punctate on its posterior face, from each puncture
arises a pale microscopic hair.
Head at least one-quarter longer than it is wide, parallel-sided,
slightly narrower behind, posterior angles rounded but very
prominent, owing to the deep and almost angular occipital
emargination. Mandibles scarcely longer than half the width of the
bead, very blunt at the apex, and with a blunt tooth near the
middle of the internal margin. Clypeus almost linear, except in
the middle, where it is slightly and triangularly extended between
the frontal carinae, and produced into a small platform on the
anterior margin. The frontal carinae short and narrow, free and
raised at the sides into a lobe which ends posteriorly in a sharp
spine. Scape of antenna incrassate and flattened towards the apex,
about two-thirds as long as the funiculus; the latter 10-jointed,
all the joints except the last wider than long. The scape and
funiculus together are about three-quarters the length of the
head.
|
Pronotum
rounded in front, narrower behind than in front. Pro-mesonotal
suture well defined; mesonotum and propodeum rather flattened
above, declivity of the propodeum vertical and very short. Node of
petiole quadrate-globose, slightly wider behind than in front, the
ventral lamella produced in a wide angle. First gastral segment
narrow at the base, 2nd and 3rd segments sub-equal, and a little
longer than the 1st, 4th segment a little shorter than the
preceding, 5th segment widely and semicircularly excavated
apically, the dorsal boundary of the excavation forming a sharp
edge, ending on each side inferiorly in a short tooth.
Minor worker - TL 5-6 mm. This differs from the major in the
following characters. The colour is slightly lighter, and the head
is a little narrower behind than in front, and is only arcuately
emarginate behind. The apex of the mandible is not blunt, but ends
in two sharp teeth, the lower tooth being the larger; the tooth on
the inner margin is also acute. The pubescent hairs on the body
are longer.
Minima worker - TL 1.7-2 mm. Colour pale dirty yellow. Funiculus
9-jointed. Pilosity and pubescence stronger than in the minor.
Mandibles without a tooth on the internal margin, and with the
upper apical tooth almost obsolete, making the mandible an
elongate triangle.
This species has been recorded from the larger part of the South
African region. In Zimbabwe it is common, and more frequently met
with than any other species of the genus. (S.A.M., R.M., G.A.
colls.)" |
Polymorphism
The photomontages are of specimens collected at Grootvadersbosch
National Reserve, Western Cape, South Africa; S 33°59'39"
E 20°48'32"; at 350 m; 25-26.i.2004; by Peter Hlavac;
nest under bark. The various morphs are shown in detail on
Dorylus (Anomma)
helvolus morphs page. |
Major
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MALES |
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