The Ants of Africa

	The Ants of Africa SUBFAMILY PONERINAE - Genus Pachycondyla
Contents - Ponerinae - PONERINAE Introduction

Genus Pachycondyla F. Smith (1858b: 105)

In Tribe PONERINI.

F Smith's (1858b) description is - "Head oblong, subquadrate, the anterior margin of the clypeus rounded; mandibles large, stout and produced, their inner margin denticulate; antennae clavate; eyes placed forward on the sides of the head, ovate and of a medium size; the labial palpi 4-jointed, the maxillary palpi 4-jointed. Thorax oblong, and slightly narrowed posteriorly; the calcaria pectinate. Abdomen elongate; the node of the peduncle incrassate, quadrate or subquadrate, elevated to the same level as the first segment, and usually of nearly the same width"

Keys to historic subgenera (now used as species-groups for convenience) and species

Hölldobler & Wilson (1990) listed Pachycondyla as being the senior synonym of Bothroponera, Brachyponera, Megaponera, Mesoponera, Paltothyreus and Trachymesopus (junior synonym of Pseudoponera). Bolton (1994) used the same amalgamation but Belshaw & Bolton (1994b) still have Paltothyreus tarsatus. Brown (1973b) defined Pachycondyla as provisional senior synonym of Bothroponera, Mesoponera (and its junior synonym Xiphopelta), and Pseudoponera (and its junior synonym Trachymesopus). Snelling (1981) had it as provisional senior synonym of Brachyponera. Bolton (1995, 41) reported "Confirmation of these provisional synonyms, and Pachycondyla senior synonym of Euponera, .., Megaponera, .., Paltothyreus: Brown, in preparation". In the species catalogue, Bolton (1995) gave many "new combinations" arising from work in progress by W.L. Brown, and listed other references for modern revisionary studies (Brown, 1976, 1978). Professor Brown died in 1999 and so the revisions remain incomplete.

From Emery (1901a), it seems that quite an argument ensued between himself and, notably Forel, over the separation of Dorylinae and Ponerinae and what constitued the latter. He describes how Fred Smith, who had defined Pachcyondyla (Smith, 1858), had complained (1864) that "some continental authors have sunk" - the genus Pachycondyla which he had qualified as a "well defined genus". Emery went on to describe this was not wholly true, as Mayr and Roger had adopted Pachycondyla but had transformed it to a point which he found unrecognisable. Of the species placed in Pachycondyla by Smith, the later authors had transferred most into the new genera Paltothyreus, Bothroponera and Platythyrea, but the same authors had incorporated into Smith's genus, not only new species but all the large species from the Americas, with carinate genae, that Smith had left in Ponera. Time had marched on, however, and all the large American species, with a slender build and fine sculpture formed Pachycondyla, whereas the large, strongly sculptured species from the old world formed the genus Bothroponera, Mayr had placed some Indian forms in his genus Ectomomyrmex and lastly a large cosmopolitan residue was left in Ponera. Forel, having studied ants from Madagascar, had included in Bothroponera all large or medium sized species with the mesonotum shown by a segment after the "corselet", without a marked suture, and concluded that Bothroponera formed a sub-genus of Ponera. He, Forel, had said nothing about Pachycondyla. This genus, however, could be separated by having the maxillary and labial palps with 4 segments, whereas Ponera had maxillary palps with 1 or 2 segments and the labial palps with 2 segments.

Emery (1901a) however, described how he had found that whereas the palpal segment count was consistent in Pachycondyla, this was not a consistent feature in Ponera and Bothroponera with counts of 3 or 4 sinking the viability of this character. He examined other characters, such as genae with carinae and the placement of the eyes but these were not consistent, with Pachycondyla and Bothroponera sharing the range of characters. His answer was two natural groups -
One with the hind tibiae with a single spine; the median or posterior spine being pectinate and the lateral or anterior spine having been lost. This group had two genera - Ponera Latreille (with only the small species, coarctata, truncata, opaciceps, punctatissima, etc ) [the latter three now being regarded as Hypoponera];
and, Belonopelta Mayr [neotropical]; to this group he also reattached the genus Cryptopone Emery comprising three species.
The second group had hind tibiae with two spines, the posterior habitually long and pectinate, the anterior short and simple. This group had three genera :
Pachycondyla F Smith, on the whole large or medium sized, with the metanotal suture reduced rarely distinct; this genus could be divided into four sub-genera - Pachycondyla s.s. (all American, with the pronotum bordered with a roll, often obtuse but always distinct; Bothroponera Mayr (Old World tropics, pronotum not bordered, head not truncate behind); Ectomomyrmex Mayr (south and southeast Asia, head truncate behind, sternum of medonotum with a distinct plaque clearly limited by deep sutures); Pseudoponera new subgenus (mostly small, generally with 4-segmented palps, clypeus medially raised in several species, metanotal suture distinct, etc.).
The second genus was Euponera Forel, with the mesonotum clearly limited behind by a notch, and usually with a convex dorsum; the eyes are strongly anterior and the genae have no carinae. This genus he divided into three sub-genera - Euponera Forel, with a single large species from Madagascar, with maxillary palps with 2 segments (E. sikorae); Mesoponera new subgenus (medium or not very large, elongated, petiole of diverse shapes, with most former Pachycondyla); a small group he called Brachyponera new subgenus, with a short corselet, mesonotum raised, propodeum straight in front and enlarged behind, with the declivity indented to receive the anterior face of the petiole, which is high, domed transversely, palps with three segments).
The third genus was Neoponera, for North American forms with carinate genae.

Diagnostic Features - The amalgamation of previously separate genera means a rather broader description than before. Medium to large ants. Usually quite coarsely sculptured and dark in colour. Head with large mandibles, usually dentate, with six or seven teeth, but may be more or less, sometimes reduced to four or five. Alitrunk with promesonotal suture present and mobile, metanotal suture sometimes absent. Petiole large, often thick and nodiform. Middle and hind tibiae each with a large pectinate and a small simple spur.

The orignal Genus and subgenus descriptions, as known from Africa, are on the following cards -
Bothroponera by Mayr (1862: 717) - ; key to southern Africa species by Arnold (1915: 55) .
Brachyponera by Emery (1900c: 315; as subgenus of Euponera) - ; translation by Arnold (1915: 72) .
Ectomomyrmex by Mayr (1867a: 83) - (unavailable, pages missing in HNS pdf) .
Euponera by Forel (1891b: 126; as subgenus of Ponera) - ; translation as Genus, with key to subgenera - Mesoponera, Euponera, Brachyponera and Trachymesopus - by Arnold (1915: 63) .
Hagensia by Forel (1901f: 333; as subgenus of Mega(lo)ponera) - ; translation by Arnold (1926: 46) ; with a revisionary study (Arnold, 1951) at .
Megaponera by Mayr (1862: 734) (sometimes mis-spelt as Megaloponera)- ; translation by Arnold (1915: 46) .
Mesoponera by Emery (1900d: 668; as subgenus of Euponera [given solely as name Euponera (Mesoponera) melanaria]; actually defined by Emery (1901a: 43) - ; (junior synonym Xiphopelta Forel, 1913a: 108; synonymy Wheeler, 1922: 775) - translation and key to southern Africa species by Arnold (1915: 64) (the key includes species he later placed in Hagensia).
Ophthalmopone by Forel (1890b: cxi) - ; translation by Arnold (1915: 43) .
Paltothyreus by Mayr (1862: 735) - ; translation by Arnold (1915: 43) .
Pseudoponera by Emery (1900c: 314; as subgenus of Pachycondyla; junior synonym Trachymesopus Emery, 1911d: 84) - ; translation by Arnold of Trachymesopus (1915: 74) .

Note - Euponera Forel. Resembling Bothroponera but smaller and much more finely sculptured.
WORKER monomorphic, with subtriangular mandibles the apical margins of which are dentate. Cheeks not carinate. Frontal carinae closely approximated expanded and lobular in front and concealing the insertions of the antennae. Eye placed near or in front of the anterior third of the head, sometimes vestigial or even absent. Clypeus rounded and obtusely pointed in front, usually carinate. Antenna slender, 12-jointed, the scapes slightly thickened apically but not clavate. Thorax shaped somewhat as in Bothroponera, but with distinct metanotal suture and usually with distinct metanotal constriction. Petiole surmounted by a thick transverse scale. Middle and hind tibiae, with two spurs; claws simple.
FEMALE winged; in some of the subgenera scarcely larger, in one (Brachyponera) considerably larger than the worker; in other respects similar.

Wheeler noted that Emery had divided this genus into four subgenera: Euponera, sensu stricto; Mesoponera; Brachyponera; and Trachymesopus. Euponera, with a single species, is confined to Madagascar; the other subgenera have a wide distribution over the tropical and subtropical portions of both hemispheres. The species live in the ground, either in crater nests or under stones, logs, etc. Euponera (Mesoponera) castanea (Mayr) of New Zealand lives, as a rule, in rotten logs and stumps. The colonies of Brachyponera are rather large and populous, those of the other subgenera much smaller. In the subgenus Trachymesopus there is a tendency to hypogaeic (underground) habits and, therefore, there is a degeneration of the eyes in the workers.

I feel the descriptions by Bernard (1952) of the now synonymised genera may have merit, so:-

Bothroponera - medium sized, only slightly subterraneous, foraging in small groups; emit from the anal glands a sticky substance rather than using the sting; all slender and with little sculpturation.
Brachyponera - evolved Euponera, with exceptional (for Ponerines) obese queens and an often omnivorous habit. Two species were known from Guinea, but were not found on Nimba.
Euponera - a large, pan-global, strongly heterogenous genus but sexual forms insufficiently known, precluding sound revision; African forms totalled 17 species, divided amongst the 5 reconised subgenera; the state of the taxonomic knowledge was is shown by the fact that of 8 species found at Nimba, 6 were undescribed. Often more subterranean than Bothroponera, and with a more primitive structure (longer mandibles, thorax segments well separated one from another). Mandibles commonly with 13 teeth, but may be more.
Trachymesopus - a primarily Malay and Indo-Pacific group, with few African forms. From Nimba, a single form, thought to be new was collected (now junior synonym of brunoi).
Xiphopelta - group defined by Santschi as a subgenus to accommodate former Mesoponera with more slender mandibles, less dilated promesonotum, and especially where the first funicular segment is larger than the others. Prior to Bernard's work, two African forms were known, with senegalensis from West Africa (Senegal and Guinea). Four new forms were found on Mt. Nimba.

Given that Brown seems not to have completed the review mentioned by Bolton (1995), identification remains a problem. Thus, I have decided to also incorporate the separations used by Wheeler (1922) and retained by Bolton (1973a).

Unassignable forms

Pachycondyla species (indet.)

In Ghana, workers were found by Belshaw & Bolton (1994b) in leaf litter samples, 18 workers, and soil, 7 workers, from cocoa at Asiakwa, and primary and secondary forest at Bunso and CRIG.

Pachycondyla new species

In Ghana, a single worker was found by Belshaw & Bolton (1994b) in a leaf litter sample from secondary forest at Bobiri.

Keys to historic subgenera (now used as species-groups for convenience) and species

PONERINAE Introduction

href="pachycondyla.htm"