The Ants of Africa
Genus Dorylus - Subgenus Dorylus
Dorylus (Dorylus) helvolus (Linnaeus)
{Dorylus (Dorylus) helvolus}

Dorylus (Dorylus) helvolus (Linnaeus)

return to key {link to the Hymenoptera Name Server} Type locality South Africa (Vespa helvolus, Linnaeus, 1764: 412, male; illustrated by Coquebert, 1798, Plate XVI); junior synonyms dorylus (Lamarck, 1817: 101, male [unavailable on HNS]) 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 {original description}; Lepeletier de Saint-Fargeau (1835: 213) gave a description, this is at {original description}. Emery's (1895j: 714) gave a full, illustrated description; this is at {original description}; with the illustrations on {original description}. Smith's (1858b) brief description of punctata is at {original description}; Mayr's (1865) illustrated description of the planifrons male is at {original description}; Arnold's (1946) illustrated description of pretoriae is at {original description}.

Wheeler (1922) listed it also from Togo (Bismarckburg, Büttner), Nigeria (Agege by W.A. Lamborn); plus many mostly southern Africa records.


{Dorylus helvolus minor worker}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.


{Dorylus helvolus pretoriae}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.)"


{Dorylus helvolus pretoriae}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.


{Dorylus helvolus pretoriae major}Major


{Dorylus helvolus pretoriae minima}


{Dorykus helvolus male} MALES


{Dorykus helvolus male}

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© 2007, 2008 - Brian Taylor CBiol FIBiol FRES
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