Centromyrmex feae

Bolton, Barry & Fisher, Brian L., 2008, 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, pp. 1-37 : 14-15

Centromyrmex feae group

Eight Afrotropical species and the extralimital species C. feae , from the Oriental and Malesian regions, form a group of closely related species, the feae group, named for its first-described member. Workers and queens with characters of the genus, as listed above, and also with the following characters diagnostic of the group, of which apomorphies are in italics.

Worker and queen (gyne)

Mandible elongate-triangular and strongly downcurved (MI 52–84 in workers). Mandible pointed at apex but the point continues the line of the long axis of the mandible; there is no differentiated inflected apical tooth.

Mid-points of frontal lobes in workers separated medially by a narrowly triangular strip of cuticle, the mid-points of the lobes conspicuously not touching.

Frontal groove on mid-dorsum of head is broad and extends far posterior of the terminus of the frontal lobes.

Pronotum marginate anterodorsally; pronotal dorsum forms a plateau behind the anterior margination.

Mesosoma in profile with anterior portion of propodeum sloping down from the mesonotum so that the posterior half of the propodeal dorsum is on a much lower level than the mesonotal dorsum (worker only).

Metanotal groove absent (worker only).

Metasternal process absent. A thickly rounded oblique tumulus of cuticle arises on each side of the fully exposed metasternal pit; the tumuli diverge posteriorly and terminate at the metacoxae.

Propodeum unarmed, in dorsal view bilaterally compressed so that the dorsum is narrow.

Propodeal lobes extremely reduced to vestigial.

Orifice of propodeal spiracle subcircular to elliptical, abutting the bulla of the low metapleural gland.

Petiole with at least a short anterior peduncle.

Subpetiolar process small, in profile a short, slender spine or a small, acutely triangular tooth.

Procoxa hypertrophied, very swollen and much larger than the mesocoxa and metacoxa; in profile procoxa >> mesocoxa> metacoxa.

Protibia swollen and disproportionately large.

Protarsal segments 2–4 very strongly expanded laterally, deeply V-shaped, the apices of the V terminating in a very coarse spiniform seta on each side.

Mesotibia with spurs absent.

Metatibia with a single, large pectinate spur.

Metabasitarsus very short, at most only about half the length of the metatibia.

Prora represented by a pair of weakly divergent ridges on anterior face of first gastral sternite, one on each side below the helcium; space between the ridges shallowly concave (extremely reduced in raptor ).

Scapes and all dorsal surfaces of head and body with standing setae present except for sloping portion of propodeum, where they are completely absent, and posterior propodeal dorsum, where they are absent or represented by one to a few very short standing setae. Pubescence generally sparse to absent.

Queen only. Transverse suture present on the mesopleuron that divides the sclerite into anepisternum and katepisternum (absent in workers). Mesosoma with full complement of flight sclerites. Hind wing with jugal lobe present.

Comments

In most worker specimens the mesonotum appears to have a short elevated face immediately behind the promesonotal suture, and the top of this elevated face is usually equipped with a transverse margination. However, in isolated specimens within series the elevated face is absent. It is suspected that when the pronotum is fully flexed upward, the posterior margin of the pronotum slides up the short elevated anterior section of the mesonotum until the dorsal surfaces of the two sclerites are on the same level.

The habitus of feae group workers is distinctive, the most striking feature being the strange morphology of the legs. The forelegs appear fossorial and the middle and hind legs squat and spiny. All six are short, strong, and powered by the enormously developed coxae, especially the hypertrophied procoxae. Add to this the eyeless head with elongate-triangular, downcurved mandibles, extremely flattened scapes, anteriorly marginate and plateau-like pronotum, strongly sloping anterior portion of propodeum in profile and bilaterally compressed anterior propodeal dorsum, and the result is an appearance that is unlikely to be confused with any other ponerine ant in the region.