Dorylus (Anomma) nigricans Illiger

Type location Sierra Leone (Illiger, 1802: 188, male) from a single male specimen. Bolton (1995: 179), had Mayr (1896: 225) as giving a worker description. Mayr, however, did not provide a description, simply reporting a collection from "Kamerun", although he made a number of comparisions to the workers of "nigricans" in a description of the new species D. emeryi..

Illiger's (1802) description is at .

Raignier & van Boven (1955) cite Illiger's description as - "Schwärzliche Aemsenwespe [blackish wasp], nigricans, brunneo-holo-sericeus, abdominis petiolo acetabuliformi. Lange : Einen Zoll [ca TL 25 mm] bis einen Zoll und drei Linien [TL 28.4 mm]". The specimen was a little bigger than the already known species Dorylus (Dorylus) helvolus and without hairs; the wings of nigricans were smoky black with black veins.

Forel (1909b: 11) in his notes on emeryi noted nigricans MALE - HW 5.0, HL 6.0, gaster 5.6 mm.

Emery's (1895j: 710) illustrated the male genitalia at . Earlier in the same work (Emery, 1895j: 701) listed "1. Subg. Anomma SHUCK. - Typus: d. nigricans Illig. (burmeisteri SHUCK.). He reiterated this apparent synonymization in his key to separate workers (p 706).

Emery (1910b), in Wytsman's "Genera Insectorum", Subfamily Dorylinae, gave illustrations of what he labelled as the male, queen and major worker of D. nigricans, however, Emery gave no indication of his source of the information or justification for regarding the queen and worker as nigricans. I reproduce the illustration right.

Wheeler (1922) lists many findings from all over sub-Saharan Africa and into Sudan and Ethiopia but these have to be regarded as only recording members of the loose "nigricans".

When Raignier & van Boven (1955) wrote, and still to this day, it seems the association of workers, let alone queens, with this species had not been demonstrated beyond reasonable doubt. Raignier & van Boven described how their finding of the three life stages in the nest of Dorylus (Anomma) wilverthi was the first and only example of all three life stages in one nest for any Anomma species. They quote how the association between the male of nigricans and the workers of rubellus (as rubella, later adjudged by Emery, 1892d: 554, to be a sub-species of burmeisteri) was "demonstrated" by Savage (1849: 196) who found a dozen wingless males in a column of the workers; but go on to relate how they found wingless Anomma males in worker columns of other species and even found a Typhlopone male in a column of wilverthi workers. Arnold (1952) and Van Boven (1972) also drew attention to the attempt by Forel (1912j) to cast light on the situation.

Santschi (1937b: 95), recording nigricans males from Cameroun, noted the specimens were much more obscure than burmeisteri, the wings were clearer and the nerves were blackish.

Santschi (1930a: 55) described what he regarded as the soldier & worker of "nigricans" from Mali (Bamakou, by Andrieu); this is at . As with other authors, he did not see either a queen or male and noted only small differences from burmeisteri soldiers and workers. He pointed out that nigricans s.s. was known only from the male.

The photomontage of a specimen from Ivory Coast is collated from http://www.antweb.org/description.do?rank=species&name=nigricans&genus=dorylus&project= where a set of images of a male is accompanied by two sets of worker specimens, a major and a media 1 (below).
The identification by Caspar Schöning as D. nigricans appears to be a good match to Santschi's description but I presume that, as Santschi noted, this is as a "most likely candidate" from comparison with other specimens, e.g. of Dorylus burmeisteri and Dorylus arcens. I note, however, that the male shown on Antweb was collected at the same location, Tai National Park, but at light and not from a nest.

Media 1