The Ants of Africa
Genus Cerapachys


Genus Cerapachys F. Smith (1857a: 74), includes previous Phyracaces

Diagnostic Features - Antennae 11- (former Parasyscia) or 12-segmented, the apical funicular segment greatly swollen, forming a club. Genae longitudinally carinate, eyes present. Petiole a massive node, never marginate laterally. The gastral constriction may be extreme, so that in some species there is a petiole and a post-petiole. Middle and hind tibiae with two spurs, claws simple.

Smith's (1857a) genus definition is at {original description}. Emery (1902c) gave revisionary notes - these are at {original description}.

Described as uncommon by Bolton (1973a), who remarked that all known species raid the nests of other ants for food. They are generally specialist feeders on other species of ants, hence the armoured nature of the body (Hölldobler & Wilson, 1990, page 569). Brown (1975) observed Cerapachys species in Madagascar and India attacking nests of Pheidole species.

Brown (1975) separated the African species into the following groups: the wroughtoni group, from S. Africa, of small species, with 12-segmented antennae, the eyes minute or absent, and promesonotal suture well developed; the cribrinodis group (centurio, cribrinodis, sudanensis and villiersi from West Africa and the Congo Basin); the mayri group (coxalis, foreli, and nkomoensis from West Africa and the Congo Basin); and indeterminate (decorsei and similis).

Arnold (1926) gave a key to South African species, this is at {original description}. Brown's (1975) key is at {original description}.

Brady et al. (2014) provide evidence from DNA studies that within Cerapachys the group with marked lateral margination on the petiole was distinct enough to perhaps warrant elevation to genus status under the name Lioponera (type species longitarsus Mayr 1879: 666, type location India). As yet, however, that seems to remain invalid as a formal published genus. See the subfamily page (link above) for more information. The species keyed from 5 below would be Lioponera, plus the Senegal specimens that may be the previously unreported workers of noctambulus.
Mayr's (1879) description of Lioponera, with longitarsus is at {original description}. See Cerapachys longitarsus.

Key to workers of species known from Africa (after Brown, 1975).

¤ Male only known; darkish red-brown TL 3.0 mm (no images available)
Chad - decorsei
¤ Male only known; black TL 2.8-3 mm - image on species page
Ivory Coast - similis
¤ Male only known; black TL 3.5 mm (no images available) Kenya - niger
1 Antennae with 11 segments 2
-- Antennae with 12 segments 4
2 Eye large 2A
-- Eyes reduced, with less than 15 facets 3
2A {Cerapachys sudanensis}TL 2.8-3.8 mm; sculpturation only of scattered hair pits, reduced to tiny on gaster; petiole with concave anterior face; shiny, colour dark brown .
. {Cerapachys sudanensis} Pan-African - sudanensis
-- Cerapachys noctambulus workerTL ca 4 mm; distinctively bicoloured with dark red-brown posterior to gaster contrasting to rest of body; workers speculatively associate with type male (image on species page).
If so, the former synonymy under longitarsus was wrong.  That has 12-segmented antennae, smaller eyes, shorter erect pilosity and a relatively small near circular postpetiole when seen from above.
Senegal, Tunisia, Egypt & Yemen - noctambulus
3 {Cerapachys piochardi}TL 3.5 mm; smooth and shiny with almost whole of head and alitrunk with large pits from which a yellowish hair arises, finer pits on the posterior four segments of gaster; antennae and legs with very fine decumbent pubescence; ferruginous yellow with apex of gaster browner [nothing given by Brown, 1975] .
. {Cerapachys piochardi} Syria & Lebanon {extra-limital] piochardi
-- {Cerapachys nitidulus}TL 3.3-3.4 mm; shiny, sparsely punctate; piceous, appendages medium brown .
. {Cerapachys nitidulus} West Africa & Congo Basin - nitidulus
Antennae with 12-segments

4 {Cerapachys foreli petiole}Petiole node with sharp dorsolateral angles 5
-- {Cerapachys sudanensis node for key}Petiole node without dorsolateral margins, dorsum smoothly rounding into sides 11
5 Cerapachys braunsiPetiole node from above with 2 broadly rounded nodes, separated by a deep concavity; TL 3.5 mm; piceous South Africa - braunsi
-- Petiole node with angulate or dentate posterolateral angles 6
6 Alitrunk coarsely longitudinally costulate for entire length, colour black 7
-- Alitrunk dorsum smooth or punctate; longitudinal costulae, if any, confined to anterior and posterior extremities 8
7 {Cerapachys foreli}Head smooth; TL 3.5-3.7 mm; dark brown to black .
. {Cerapachys foreli} West Africa & Congo Basin - foreli
-- {Cerapachys occipitalis}Head with longitudinal costulae, at least on occiput .
. {Cerapachys occipitalis} Guinea - occipitalis
8 Petiole node with fine sculpture whereas alitrunk smooth; petiole also with much denser pubescence. Propodeal declivity smooth 9
-- Alitrunk, petiole, postpetiole and gaster shining, with small but very distinct round punctures 10
9 {Cerapachys vespula antenna}Eye small < length of apical segment of funiculus; TL 3.4 mm (Kenya) 4.2-4.5 mm (South Africa); piceous .
{Cerapachys vespula cooperi}cooperi Kenya (montane) & South Africa - vespula
-- {Cerapachys coxalis}Eye larger > length of apical segment of funiculus; TL 2.8 mm (Nigeria slightly larger); black .
. {Cerapachys coxalis} Zimbabwe & Nigeria - coxalis
10 Cerapachys nkomoensis queenTL 4.2-4.6 mm; scape reaches posterior third of head; shiny, black (queen shown)
Congo Basin - nkomoensis
-- {Cerapachys braytoni antenna}TL 2.8 mm; petiole without postero-dorsal teeth; colour ferruginous except lower postpetiole and gaster which are black Kenya - braytoni
return to key Petiole node without dorsolateral margins, dorsum smoothly rounding into sides --
11 Eyes minute or absent 12
-- Eye quite distinct to moderate in size 13
12 Cerapachys wroughtoniTL 2.0-2.3 mm; with distinct promesonotal suture; eyes absent; smooth (other than punctures) and shiny, yellow brown southern Africa - wroughtoni
-- {Cerapachys kenyensis}TL 4.3 mm; promesonotum without any sign of suture; eye very small but distinct; dark ferruginous
. {Cerapachys kenyensis} East Africa - kenyensis
13 {Cerapachys centurio}Petiole node slightly but distinctly longer than broad; TL 5.6-5.7 mm Central Africa - centurio
-- Petiole node broader than long 14
14 Petiole node with distinct median point in posterodorsal margin 15
-- Petiole node with straight or slightly concave posterodorsal margin 16
15 {Cerapachys peringueyi}TL 4.0 mm; petiole with median point in posterior margin, dorsum in profile convex; ventral lobe of petiole with distinctive angles at anterior and posterior; castaneous .
. {Cerapachys peringueyi} South Africa - peringueyi
-- {Cerapachys afer}TL 2.4-3.0 mm; black; petiole with flat dorsum in profile .
.. {Cerapachys afer} East & southern Africa - afer
-- Cerapachys arnoldiTL 3.5 mm; petiole assumed similar; paler and more reddish than peringueyi South Africa - arnoldi
16 {Cerapachys sylvicola}TL 4.3 mm; dorsum of head, alitrunk and pedicel very finely roughened and opaque; first gastral segment with very fine dense puncturation on shiny surface; black .
. {Cerapachys sylvicola} South Africa - sylvicola
-- Dorsum of head mostly smooth or nearly so 17
17 {Cerapachys lamborni}TL 5.0 mm; petiole and postpetiole with coarse, contiguous and confluent punctures; dark reddish-brown east and south central Africa - lamborni
-- Petiole and postpetiole otherwise sculptured 18
18 {Cerapachys validus}TL 4.3 mm; petiole from above near square; black Zimbabwe - validus
-- Petiole from above with posterior wider than anterior 19
19 {Cerapachys faurei} TL 2.7 mm; pale burnt sienna brown .
. {Cerapachys faurei} South Africa & Tanzania - faurei
-- Darker reddish-brown to black 20
20 {Cerapachys villiersi}TL 2.6 mm; head, alitrunk and petiole with large deep puncturations; uniform brown-red, shiny, appendages yellow; .
. {Cerapachys villiersi} Guinea - villiersi
-- Head, alitrunk and petiole with smaller, shallower puncturations 21
21 {Cerapachys cribrinodis lateral head}TL 3.7-4.0 mm; postpetiole with deep ventral process; sculpturation of small hair pits; blackish-brown, apices of body and appendages brownish-red .
. {Cerapachys cribrinodis} West Africa & Congo Basin, east into Kenya - cribrinodis
-- Cerapachys natalensisTL 4.0 mm; pronotum wider; pedicel more weakly sculptured but alitrunk and head more densely punctured; antennae and mandibles entirely reddish South Africa - natalensis

Cerapachys new species.

Found in Ghana, by Belshaw & Bolton (1994b) in leaf litter samples from the semi-deciduous forest zone, with single workers from primary forest at Esukawkaw Forest Reserve, and secondary forest at Atewa Forest reserve and CRIG.

Cerapachys species F (as Phyracaces species F)

From Ghana in a cocoa canopy sample, by Room (1971).

© 2007, 2008, 2009, 2010, 2011, 2013, 2014, 2015 - Brian Taylor CBiol FSB FRES
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