Oligomyrmex (Aneleus) politus (Santschi)

Minor - Type location Kenya (Aneleus politus n. sp., Santschi, 1914b: 79, illustrated, minor; Consani, 1951: 170, queen; placed in Oligomyrmex by Ettershank, 1966: 124) Blue Post Hotel, Kikuyu, i.1912 - see below.
subspecies nicotianae (Sporocleptes nicotianae n. sp., Arnold, 1948: 220, illustrated, worker) from Zimbabwe - no images on Antweb (February 2015).
junior synonym villiersi (see below for details) and images.
Minor and queen only described (see Bolton, 1995) .

Almost certainly also the senior synonym of Oligomyrmex punctatus.

Santschi's (1914b) description is at . Consani's (1951) description of the queen is at . Arnold's (1948) description of nicotianae is at .

Bernard's (1952) description, with his genus definition, as Nimbamyrma, is at . From his description it seems very likely this worker is a simple junior synonym of politus - see below.

The photomontage of the type worker is collated from http://www.antweb.org/specimen.do?name=casent0913517

There seems a strong possibility that this could be separable as a distinct monotypic Genus. Both Arnold (1948: 220) and Bernard (1952: 240) suggested that was the case. Curiously despite several collections, from Kenya, Zimbabwe (nicotianae), Guinea (villiersi, Bernard) and Nigeria (below), there has been no definite finding of a major morph. Bernard (1952) also refers to numerous subterranean workers (of Nimbamyrma) having been collected in Angola. Moreover, the size of the reported queen (Consani, 1951) at TL 10 mm is quite remarkable for the genus Oligomyrmex. The queen of paetus (above) is TL 4.5 mm, and of perpusillus arnoldi is TL 3.8 mm. The few descriptions of Oligomyrmex queens all describe the morphology as similar to that of the soldier, particularly that the head is rectangular, somewhat longer than wide. The head of Consani's queen is quite different (see comparative illustration below), being much more like that described for Carebara queens, as much wider posteriorly and at least as wide as long, often wider.

Bolton (1995: 299) refers to Arnold (1952a: 460) as recognising nicotianae as a subspecies of politus. Consani (1951) has a note that Arnold, in a letter, synonymized Sporocleptes under Aneleus. When Arnold (1952a) is examined, however, this synonymy is justified as -

"Mr William J Brown (Harvard University) has drawn my attention to the close similarity between Sporocleptes nicotianae Arn., and Aeneleus politus Sant., .... and has suggested there probably is a synonymy. He also kindly sent me a specimen of Aeneleus politus, collected at Blue Post Hotel, Kenya, and determined by Menozzi".
"A comparison of this specimen with Sporocleptes nicotianae proves that Sporocleptes must be placed in synonymy with Aneleus, and that nicotianae may be regarded as a race of politus, from which it differs as follows. The head is much less convex transversely, the epinotal [propodeal] teeth are longer, the sides of the epinotum are reticulate, the apex of the node of the petiole is wider, and the colour is much paler. Santschi's figure is inaccurate, as the membranous extension ventrad of the epinotal spines has been omitted".

To me, all that shows is that the single specimen designated Aneleus politus by Santschi, the specimens designated S. nicotianae by Arnold and the specimens designated Nimbamyrma villiersi, and so-on, are variants of a single pan-African species. Arnold does not seem to have considered whether or not his recognition of a new genus was correct and that it was Santschi who was in error in placing it in Aneleus.

Bolton (1987) refers to the Pheidologeton group of Myrmicine genera as including Anisopheidole Forel (a monotypic Australian genus), Carebara Westwood, Lophomyrmex Emery (an Oriental, Indo-Australian genus), Oligomyrmex, Paedalgus Forel (queens have TL range 5.4-6.9 mm, HW = HL;with associated workers TL 1.4-1.6, Bolton & Belshaw, 1993) and Pheidologeton. Bolton & Belshaw (1993) considered that the monomorphic Carebara and Paedalgus possibly could be combined in a single genus, comparing them with Oligomyrmex which they declared as having all its known species being dimorphic in the worker. They noted also that Carebara and Paedalgus differ from Oligomyrmex in having queens which are far larger than the minor workers (e.g. Carebara vidua - queen TL 24 mm, minor TL 1.6-2.0 mm).

The wing structure of Consani's queen, however, is typical of a Pheidologeton-group member, having a closed cell where Rs joins R. Until further evidence arises to confirm that the queen described and illustrated by Consani is actually that of politus the Genus question must remain open.

Oligomyrmex (Aneleus) villiersi (Bernard)

Minor -
Nimbamyrma villiersi n. sp.
TL 1.8 mm; colour bright yellow, very shiny, with almost no puncturation or sculpturation other than striated or reticulated areas on the thorax. No pubescence, short hairs on the appendages; raised sensory hairs, no more than 4 per segment on the head, thorax and abdomen. Head gross, very rounded, a little longer than wide. Occiput scalloped, concave and lightly bordered. Clypeus large, triangular, median border rectilinear, armed with two lateral teeth. Mandibles stout, slightly arched, with 4 large teeth and 2-3 denticles; palps very short. Eyes level with the base of the scapes, black, miniscule, with 9-11 discontinuous facets. Antennae slender with the scape not reaching the vertex; funiculus of 10 segments, only 2-6 wider than long. Thorax slender, anterior bordered, striated thereafter; generally smooth; fine reticulation on prosternum; mesosternum and mesopleuron more so; strong longitudinal striae on metanotal groove. Propodeum short with two strong teeth, plus two shorter inferior teeth. Petiole and postpetiole very long and slightly elevated. Gaster small.

Type location Mt. Nimba, Guinea, two minors only, from the north-east forest, leaf litter sifting by Villiers, ix.1946 (Nimbamyrma villiersi, Bernard, 1952: 241, illustrated, minor); minor only described (see Bolton, 1995).

The photomontage of the villiersi type worker is collated from http://www.antweb.org/specimen.do?name=casent0913514

Nigeria specimens (Pheidologeton species in Taylor, 1980a: 41). Only a single morph was present in the CRIN collection, presumed to be a minor. TL 1.87 mm, HL 0.53, HW 0.47, SL 0.39, PW 0.26

Colour golden yellow. Unsculptured except for slight reticulation on the lateral mesonotum. Erect hairs relatively long and sparse. Propodeal spines long, narrow and acute; promesonotal suture absent; petiole and postpetiole with laterally compressed nodes.

Found in leaf litter at the Cocoa Research Institute of Nigeria, Idi Ayunre, by B. Bolton, who determined the generic status (personal communication, 1976).

The illustration of a queen is from Consani (1951).

From the limited information available, this is close to the queen of Oligomyrmex longii Wheeler  [Carebara longii in Fernandez, 2004]  http://www.antweb.org/specimen.do?name=casent0103521
[Erebomyrma longii, Wheeler, 1903a: 140; placed in Oligomyrmex by Ettershank, 1966: 123) type location USA.

Note: A queen is shown at http://www.antweb.org/specimen.do?name=casent0217139 with the species name given as Carebara polita. This bears no resemblance to the Consani illustration. It also poses a question as to size because the scale lines on the three photographs, lateral, dorsal and head, give different sizes for the head width (the only directly comparable parameter).

From his examination of specimens sent to him by B Bolton (location not given but, by deduction, includes some from Bolton's Nigeria finding) and others seen at the MCZC (no location given), Fernández (2010) placed Nimbamyrma villiersi in Carebara but appears to have been unaware of the close similarity with the prior named O. politus.

I have collated the images shown above with those given by Fernández. The montage shown below shows the available images. The photographs match the drawing I made in 1976 and Fernández confirmed that the Bernard drawing exaggerated the metapleural process. Now (February 2015) the availability of type images (above) confirm the negligible differences between politus and villiersi.