Dorylus (Dorylus) brevipennis Emery

Male Type locality Tanzania (Emery, 1895j: 721, illustrated, male; Emery 1901c: 192, worker; Boven, 1975: 193, queen) types collected at Tabora, Orniyaneimbe, by René Oberthür, wrongly noted as "Westafrika"; subspecies marshalli (Emery 1901c: 193, worker & male, illustrated) from Zimbabwe, and zimmermanni (Santschi, 1910g: 738, illustrated, soldier, worker & male, illustrated) from Congo; unavailable name bulawayensis (as var of zimmermanni, Forel, 1914d: 215, worker) from Zimbabwe, coll G Arnold; all forms known (see Bolton, 1995) .

Emery's (1895j) description of the male is at . Emery's (1901c) description of the worker and marshalli is at . Santschi's (1910g) description of zimmermanni is at and . Forel's (1914d) description of bulawayensis is at . J. van Boven (1975: 189) described the queen from Rubona, Rwanda, collected by H. Neel, 19.iv.1973, and gave an illustration (right) of the major; see

Wheeler (1922) listed many findings from eastern Africa (from Sudan south to Zululand) and from Zaïre (Kohl; at Medje, Lang & Chapin).

Bernard (1952) reported it as common at Banco, Ivory Coast, and a probable identification of a single small worker from Guinea, Nion (T44, Lamotte).

Arnold (1915: 122) provided a description of the type, from Emery (1895j, 1901c) -
"Worker - TL 8.5 mm. This worker is deceptively like that of affinis, differing only in its smaller size in the major forms, and in having the petiole shorter and wider behind than in that species."
He noted that it had not been recorded from southern Africa but he gave a description of the variety marshalli, which was originally found at Salisbury, Zimbabwe (from Emery, 1901) -
"Worker maxima - TL 8.5 mm; head, 2.8 mm long X 2.3 mm wide. The colour is a little darker than the type species, and the puncturation of the petiole, which is less shining, is more abundant. Otherwise like the type".
On race zimmermani, Arnold wrote -
Major - TL 8 mm. Colour, puncturation and general characters exceedingly similar to those of helvolus. The sides of the head are, however, slightly sinuate; the teeth of the mandible more acute, and the petiole a very little wider. The ventral lamella of the petiole is produced behind into a short spine, pointing downwards (the lamella is truncate in helvolus majors.
Worker media - TL 6-3.4 mm. These do not present any appreciable differences to distinguish them from helvolus of the same size; the ventral lamella is not spinously produced as in the major. Of the smallest (2 mm) described by Sanstchi, I have seen no examples; they have 8-joined antennae".
He noted there was nothing, other than the ventral lamella of the major petiole that separated them from helvolus. He also cited Santschi's descriptions of males from Madingou, French Congo.

Arnold gave a translation of the male description - "A small species, of a somewhat stumpy build. Particularly noticeable on the head are the small but slightly projecting eyes, which are separated from the base of the mandibles by a distance about equal to the thickness of the scape. The mandibles are plainly smaller than in affinis. The antennae are long, the scape shorter than the first 5 joints of the flagellum, or about as long as one-third of the latter. Thorax stout, petiole as in affinis. There are some erect hairs on the pronotum; on the mesonotum and scutellum only a long, adpressed pubescence, which is hardly glossy and does not conceal the chitin. Colour brownish-yellow, head excepting the mandibles dark brown; on the mesonotum in front the is a short median band of darker colour, and also two lateral bands which do not reach the anterior margin; the femora and petiole brown; the margins of the abdominal segments brownish. Wings noticeably short, glassy and with brown nervures; the transverse nervule joins the middle of the root of the cubital. The genital organs are constructed much as in affinis, but the outer parameres are markedly broad, not excised at all laterally. Length 20-21 mm; head and thorax, 8 mm; width of thorax, 4 mm; anterior wings, 12.5 mm.

Polymorphism

This photomontage of zimmermanni cotypes is collated from The Smithsonian Institute images at http://ripley.si.edu/ent/nmnhtypedb/public/specimeninfopage.cfm?publicconsumption=1&typespecimenID=972.

The various morphs are shown in detail on the Dorylus (Dorylus) brevipennis morphs page. Also shown are males and a major specimen from the Central African Republic.