Cerapachys occipitalis (Bernard)

Type locality Guinea (Phyracaces occipitalis, Bernard, 1952: 216, illustrated, worker); holotype worker only from log mould, Mt. Nimba, Station B6.14, Camp IV, 1000 m, forest, by Lamotte - resurrected here from synonymy with foreli (by Brown, 1975: 22; and in Bolton, 1995) - see below
Worker only described .

TL 3.9 mm; colour black, shiny, appendages red-brown; head shiny anteriorly but posterior third with 20 strong longitudinal rugae, not reaching as far forward as the eyes. Dorsum of whole thorax and declivity of propodeum with 16 similar rugae. On the petiole these rugae intercross, giving the appearance of elongated dimples. The gastral segments have serrated rows of large round puncturations. Also, fine yellow hairs are less dense than most other species, giving a relatively shining appearance. Head rounded less angular than most other African relatives. Lower border of cheeks limited by an entrenched carina for the whole length, as in foreli (after Bernard, 1952).

Bernard remarked on the poor original description of foreli  by Santschi (1914d, type location Ghana), and noted that he had not found the foreli holotype in Santschi's collection although it might be in the Silvestri collection. Nevertheless, apparently basing his comparison on "foreli" specimens from Ivory Coast, he felt clear differences could be used to separate the two forms, viz - foreli had an entirely smooth head, with more marked posterior angles; the eyes were bigger, taking up one-third of the head length (here eyes about one-quarter); declivity of propodeum concave (here flat); petiole much less strongly sculpted; base of gastral tergites with transverse striae (here without). Certainly, comparison with the Phyracaces langi cotype image from the MCZ and an Antweb worker from Gabon, justifies Bernard's decision to define a new species (I suspect that Brown, 1975: 56, as with others of his revisions, paid insufficient attention to Bernard's descriptions). Brown (1975) wrote of it as "very crudely described and figured by Bernard".

The MCZ (H O Lang) specimen of Phyracaces langi and an Antweb worker from Gabon are some 20% larger than the occipitalis I have seen but have proportionally smaller eyes.

Bernard's (1952) description is at

Nigeria specimens (as Phyracaces langi, Taylor, 1976: 35). WORKER. TL 3.73 mm, HL 0.78, HW 0.68, SL 0.39, PW 0.50
Colour black, shiny. Extremities red-brown, orange tarsi. Abundant coarse hairs all over. Smooth areas on front of head, scattered small foveolae on remainder. Antenna 12-segmented with apical three segments forming a club. Sculpturation of longitudinal striations on alitrunk, less marked on lateral surfaces. Dorsum of petiole and first gastral tergite with large foveolae, remainder of gaster with small foveolae. Node of petiole distinctly marginate laterally, armed posterodorsally with a pair of large teeth.
I collected it from leaf litter, at the Cocoa Research Institute of Nigeria, Idi Ayunre, Block E5/1; and on a cocoa pod growing at ground level. Nest in soil and dead wood on the ground.

Now (August 2013) I find this matches exactly the Liberia and Ivory Coast workers shown below.

So, either one should accept Brown's comments on variability within the species "Cerapachys foreli" or one should separate the Congo Basin forms as being Cerapachys langi Wheeler (1922: 54)  and the West African form as Cerapachys foreli. More needs to be done.

The photomontage of the type worker is collated from http://www.antweb.org/specimen.do?name=casent0915487

Oxford University Museum specimens

Cerapachys occipitalis B Taylor det.

Liberia E Poirier Yekepa PF 12

29.iii.2013 Nimba County 07°33’38" N 08°32’33" E

Pitfall trap Degraded secondary forest 518 m asl

1

The photomontage is of a worker from Liberia, Yekepa; collector E Poirier (Yekepa PF 12).

The photomontage of a worker from Ivory Coast, originally denoted as Phyracaces santschii by W L Brown matches exactly the Liberia worker above, with the smaller size and same eye proportions.  The montage is collated from http://www.antweb.org/specimen.do?name=casent0173075