Centromyrmex species groups
These species groups were detailed in: Bolton, B. and B. L. Fisher. 2008c. Afrotropical ants of the ponerine genera Centromyrmex Mayr, Promyopias Santschi gen. rev. and Feroponera gen. n., with a revised key to genera of African Ponerinae (Hymenoptera: Formicidae). Zootaxa 1929: 1-37. PDF
Worker and queen (gyne). A small group of two Afrotropical species. Workers are known for both, the queen is known for bequaerti. Workers and queens with characters of the genus, listed above, and also the following characters diagnostic of the group, of which apomorphies are in italics.
Worker caste polymorphic.
Mandibles short, triangular (MI < 40 in workers) and with 4–7 teeth, the apical tooth differentiated and inflected.
Pronotum without margination either anteriorly or laterally.
Mesosoma in profile with dorsum of propodeum continuing the line of the mesonotum, the former not sloping steeply away from the latter.
Mesonotum behind promesonotal suture not elevated, not transversely marginate.
Metasternal process present as a pair of narrow erect spines that are very closely approximated and nearly parallel; the metasternal pit is between the spines posteriorly.
Propodeum in dorsal view broad, not strongly bilaterally compressed.
Propodeal spiracle in worker very high on the side and at about the midlength of the sclerite; orifice of spiracle long, slit-shaped.
Propodeal lobes low and rounded.
Procoxa not hypertrophied, only slightly larger than mesocoxa and metacoxa.
Mesotibia with two spurs: in all worker sizes the anterior spur is small, simple to barbulate. The posterior (main) spur is pectinate in large workers, but the pectination decreases with reduced size until, in the smallest workers, the spur is only barbulate.
Metatibia with two spurs: in all worker sizes the anterior spur is small, simple to barbulate. The posterior (main) spur is always broadly pectinate.
Petiole without an anterior peduncle; in profile the anterior face of the node rises from directly behind the anterolateral cuticular processes that protect the articulation.
Petiole node in profile becomes longer and lower as body size decreases.
Subpetiolar process large, roughly keel-like.
Prora conspicuous in profile as an elevated, roughly vertical ridge; in anterior view prora forms a transverse plate (slightly indented centrally) across the entire anterior face of the first gastral sternite.
Sculpture extremely reduced, the ants very smooth and shiny.
Standing setae present on all dorsal surfaces of head and body in worker, including dorsal surface of scape. Setae also present on ventral head and gastral sternites.
Queen only (bequaerti). Large eyes and conspicuous ocelli present. Mesosoma with full complement of flight sclerites. Transverse suture present on mesopleuron (absent or vestigial in workers except in largest examples of Centromyrmex bequaerti, where it is weakly delineated). Propodeal spiracle slit-shaped and close to metanotal-propodeal suture. Jugal lobe present on hindwing. Petiole node in profile much higher than long.
At first glance the species of the bequaerti group appear quite different from those of the feae group, and when taken in isolation their differences are arguably of genus-rank significance. However, the Malesian species Centromyrmex hamulatus forms an almost perfect morphological intermediate between the two groups. For distribution of shared and independent characters see under hamulatus, below.