The Ants of Africa

	The Ants of Africa SUBFAMILY MYRMICINAE - Genus Cataulacus
Contents - Myrmicinae - MYRMICINAE Introduction

Genus Cataulacus F. Smith (1853: 225)

In Tribe CATAULACINI.

Diagnostic Features - Head, alitrunk and gaster considerably dorsoventrally compressed and overall appearance of being armoured, and the first gastral tergite forming the whole of the gaster in dorsal view. The full adult colour is mostly uniform black or black-brown, with the antennae, tibiae and tarsi lighter, yellow or yellow-brown. Eyes usually well developed and set behind the mid-length of the head. Antennae 11-segmented with a 3-segmented club. Antennal scrobes below the eyes. Sides of head between the eye and occipital corner often have numerous laterally projecting denticles and the occipital corner usually has a tooth. The dorsum of alitrunk with sutures no more than weakly impressed or absent. The sides of the pronotum are usually marginate with a number of small teeth or an angular projection. Propodeum usually bispinose or bidentate.

Smith's (1853) genus description is at . Arnold (1917: 386) gave notes on the genus description; this is at . Arnold (1920a: 403) gave a key to South African species, this is at .

Extensively revised by Bolton (1974a), with some later additions (Snelling, 1979a; Bolton, 1982). The second review by Bolton (1982) had a fresh key, due to the recognition of species collected since 1973, a review of some of his previous synonymization, and the description of six new species. Unfortunately Bolton did not provide full descriptions of the revived species - jeanneli and lujae which were revived from synonymy with brevisetosus; and traegaordhi revived from synonymy with pygmaeus. Bolton's revised species description (1974a) is at ; with his further note (1982) at .

In Bolton's first paper, there were Nigerian records for only six species, one of which, Cataulacus huberi André, was not represented in the CRIN collection. The 1982 revision removed Cataulacus difficilis from the Nigerian list. I collected all but huberi (known from Ile-Ife in Nigeria) and found a further five species - two of which were known from countries both east and west of Nigeria, one was known from the neighbouring Republic of Benin (formerly Dahomey) and two turned out to be new species. From the information given by Bolton, four other species were likely to be present in Nigeria as they are known from countries both to the east and west. Curiously, although the Bernard (1952) treatise on Mt. Nimba, Guinea, is among Bolton's (1974a) references, he (Bolton) appears not to have included any of the Bernard records, which include pullus from Nigeria. Similarly, Bolton (1980) does not have Guinea under the listed occurrences of either pygmaeus or traegaordhi and so the quite numerous findings of "traegaordhi" from Mt. Nimba cannot be clearly identified or separated (see my species notes).

All known members of the genus are arboreal, living and nesting on trees; most are characterised by heavy body armour, presumably for defence and enabling them to co-exist with other aggressive species of ant. Some are known to be involved in the phenomenon of myrmecophily, where the host plants provide cavities for the nests to inhabit.

Most species of the genus have a relatively large range of sizes of what are otherwise monomorphic workers. The size ranges given below are taken from Bolton (1974a, 1982) but the specimens drawn all came within the appropriate size range. In the key, as in Bolton's later review (1982) the term appressed is used rather than adpressed (e.g. adpressus, used by Bolton, 1974a).

Species-groups according to Bolton (1982) -
huberi-group - egenus, huberi, inermis, kohli, lobatus, oberthueri, porcatus, pullus, regularis, tardus, theobromiclus and wasmanni;
tenuis-group - adpressus, boltoni, brevisetosus, centrurus, difficilis, elongatus, impressus, jeanneli, kenyensis, lujae, moloch, pilosus, satrap, striativentris, tenuis, vorticus and weissi;
intrudens-group - bequaerti, ebrardi, fricatidorsus, intrudens, mckeyi, micans, mocquerysi, pygmaeus, traegaordhi, voeltzkowi and wissmanni;
guineensis-group - erinaceus, greggi and guineensis.
1982 new spp not grouped - cestus, jacksoni and taylori.

Key to workers of African species (derived from Bolton, 1982):

1	Propodeum completely unarmed; propodeal dorsum transversely rugose; TL 6.1 mm	.
.		Zaïre - inermis
--	Propodeum armed, usually with a pair of distinct spines, if these reduced to teeth then propodeal dorsum not tranversely rugose	2
2	Dorsal alitrunk without standing hairs of any description or at most only 1-2 very short hairs. Generally hairs absent from alitrunk	3
--	Dorsal alitrunk with numerous standing and usually conspicuous hairs	10
3	Dorsal alitrunk strongly sulcate throughout. Appressed hairs on dorsal alitrunk; TL 3.5 mm	.
.		Ghana - adpressus
--	Dorsal alitrunk reticulate-punctate to reticulate, usually with fine rugulae but never sulcate; adpressed hairs absent from dorsal alitrunk	4
4	Petiole dorsally strongly transversely rugose or sulcate everywhere	5
--	Petiole dorsally variously otherwise sculptured	7
5	First gastral sternite laterobasally without a longitudinal margination or carina which parallels the laterobasal margination of the first tergite; femora of hindlegs antero-posteriorly compressed; TL 5.1-7.1 mm	.
.		West Africa, Congo Basin & Uganda - kohli
--	First gastral sternite laterobasally with a longitudinal margination or carina which parallels the laterobasal margination of the first tergite; hind femora not flattened	6
6	Sides of head behind eyes irregular, denticulate, crenulate or otherwise jagged; relatively broad head widening behind the eyes; laterally projecting hairs on side of head behind eyes long and conspicuous; TL 5.5-7.8 mm	,
..		West Africa, Congo Basin & Tanzania - huberi
--	Sides of head behind the eyes regular and smooth; relatively narrow-headed, without notable widening; laterally projecting hairs minute or absent; TL 4.2-6.1 mm	.
.		West Africa, Congo Basin & Kenya/Uganda - egenus
	Petiole dorsally not strongly transversely rugose or sulcate	.
7	Petiole and postpetiole in dorsal view very strongly longitudinally sulcate. Postpetiole dorsally divided into two projecting lobes by a deep median longitudinal cleft; TL 6.1 mm	.
.		West Africa & Congo Basin - lobatus
--	Petiole and postpetiole not strongly longitudinally sulcate, postpetiole not divided	8
8	Lateral pronotal margination with 2 teeth. Dorsal and lateral surfaces of petiole and postpetiole with numerous tubercles and small angular prominences; TL 5.3-7.0 mm	.
.		West Africa & Congo Basin, also Kenya - pullus
--	Lateral pronotal margination with 0-1 teeth. Dorsal surfaces of petiole and postpetiole without tubercles or small angula prominences	9
9	In full-face view head with lateral margins behind the eyes with a row of short projecting hairs; lateral anterior margin of pronotum with a single tooth; TL 6.5 mm	Zaïre - theobromicola
--	No hairs on margins behind the eyes; TL 5.4-6.8 mm	.
.		West Africa & Congo Basin - tardus
	Dorsal alitrunk with numerous standing and usually conspicuous hairs	--
10	Petiole and postpetiole strongly transverse, flattened dorsoventrally and without nodes; both very broadly and thickly V-shaped in dorsal view. Propodeum with no more than small teeth or tubercles; TL 4.0-5.5 mm	.
.		West Africa & Congo Basin - mocquerysi
--	Petiole and postpetiole otherwise; well developed propodeal spines	11
11	Hairs on clypeus and usually also on rest of head dorsum bizarre, strongly clavate or stalked-suborbicular; in most the apex of each hair is very strongly swollen, while the stem is narrow	12
--	Hairs on clypeus and head dorsum simple, usually stout cylindrical and blunt	20
12	In dorsal view, pronotal margin without an unbroken series of denticles	13
--	In dorsal view, pronotal margin with a laterally projecting and unbroken series of denticles	15
13	First gastral tergite regularly longitudinally sulcate throughout; TL 3.5 mm	Cameroun - jacksoni
--	First gastral tergite reticulate-punctate or with no more than fine rugulae	14
14	Propodeal dorsum longitudinally rugulose; TL 3.4-3.5 mm	.
..		West Africa & Congo Basin - vorticus
--	Propodeal dorsum transversely rugose; TL 2.74-3.08 mm	.
.		Nigeria - boltoni
	In dorsal view, pronotal margin with a laterally projecting and unbroken series of denticles	.
15	Bizarre hairs on dorsum of head behind the clypeus with a very short basal stem, appearing stud-like, the swollen apices set very close to the cephalic surface; HW < 0.80	16
--	Bizarre hairs on dorsum of head behind the clypeus with an elongate basal stem, never short and stud-like, the swollen apices raised well clear of the cephalic surface	17
16	HW 0.80 plus; TL 2.5 mm; in full face view eyes with inner margin weakly incurved	.
.		Pan-African ? - jeanneli.
--	HW < 0.80; TL 2.7-4.0 mm	.
.		southern Africa - brevisetosus
17	Dorsal alitrunk with weak rugulose sculpture and a blanketing dense reticulate-punctate ground-sculpture, which is very conspicuous between the rugulae, the surface matt and dull	18
--	Dorsal alitrunk with strong dense rugose sculpture, little or no sculpture between rugae, surface glossy	19
18	Denticles on lateral pronotal margins minute and inconspicuous in dorsal view; dorsum of head with short stud-like erect hairs; TL 3.4-3.5 mm	Cameroun - satrap
--	Denticles large and conspicuous, at least as large as the tooth at the pronotal corner; TL 3.0-3.2 mm	West Africa & Congo Basin, also Zimbabwe - lujae
19	Smaller species, HW 0.80 or less; body hairs relatively short; basal quarter of first gastral tergite without strong rugulae; either punctate or with feeble rugulae due to alignment of punctures; propodeal spines in profile evenly but feebly curved; TL 2.8-3.2 mm	.
.		Ghana & Nigeria - moloch
--	Larger species, HW > 0.90; body hairs relatively long; basal quarter of first gastral tergite with strong longitudinal rugulae, independent of underlying puncturation; propodeal spines in profile with basal third elevated and apical two-thirds recurved; TL 3.9 mm	.
.		Cameroun - centrurus
	Hairs on clypeus and head dorsum simple, usually stout cylindrical and blunt	--
20	Body covered with abundant, dense, very long, narrow and fine erect hairs	21
--	Erect hairs relatively sparse, short, broad and blunt, usually straight, giving ant a bristly appearance	22
21	Propodeal dorsum longitudinally rugose; dorsum of petiole with arcuate rugae; HL > 0.90, HW > 0.85; TL 3.7-4.4 mm	Western Coast - Angola north to Ghana - elongatus
--	Propodeal dorsum transversely rugulose, HL < 0.90, HW < 0.85; TL 3.1 mm	Zaïre - pilosus
22	Head relatively broad or very broad, eyes small, CI > 112, OI < 30; in dorsal view postero-lateral portion of pronotal margin produced into a large spine or triangular prominence; propodeal spines long and strong not dorsoventrally flattened	23
--	Head relatively narrow and eyes larger, CI 110 or less, OI > 32; no large spine on pronotal margin; propodeal spines usually dorsolaterally flattened	24
23	Sculpture of dorsal alitrunk a very distinct rugoreticulum with strongly reticulate-punctate interspaces; lateral margins of mesonotum usually with one or more denticles; TL 8.1-9.5 mm	.
.		West Africa & Congo Basin - erinaceus
--	Sculpture of dorsal alitrunk variable but essentially longitudinal; lateral margins of mesonotum usually without denticles; TL 4.5-8.6 mm	.
..		West Africa & Congo Basin (also ? South Africa) - guineensis
	Head relatively narrow and eyes larger, CI 110 or less, OI > 32; no large spine on pronotal margin; propodeal spines usually dorsolaterally flattened	--
24	At least posterior quarter of first gastral tergite coarsely sculptured	25
--	Posterior quarter of first gastral tergite with no more than fine sculpturation	27
25	Smaller species, HW < 0.90 but with relatively large eyes; TL 3.6-3.7 mm	Zaïre & Kenya - striativentris
--	Larger species, HW > 0.90 but with relatively smaller eyes	26
26	Dorsum of head with few and inconspicuous short stubbly hairs; TL 4.3-5.1 mm	.
.		eastern & southern Africa - intrudens (part, intrudens group)
--	Dorsum of head with numerous long stout hairs	26A
26A	With eyes relatively small, OI 41-45, head near square CI 98-104 but quite strongly convex behind the eyes; gaster dorsum with longitudinal rugae usually broken centrally; subpetiolar process small	.
..		eastern & southern Africa - wissmannii
--	With relatively large eyes OI = 47, head elongated CI 90; gaster dorsum very strongly linearly rugose, postpetiole with quite prominent ventral process	.
.		eastern & southern Africa - linearis
	Posterior quarter of first gastral tergite with no more than fine sculpturation	.
27	Occiput with a deeply incised transverse groove but no occipital crest; TL 3.7 mm	Uganda - impressus
--	Occiput without a deeply incised transverse groove	28
28	Subpetiolar process complex, antero-ventrally with a prominent broadly rounded angle and posteroventrally with an extended heel or spur, surface between these usually concave; postpetiole with a strongly developed long digitiform ventral process	29
--	Either the subpetiolar complex simple, a rectangular or subrectangular lobe unlike above, or with a feebly prominent acute angle or small tooth posteroventrally, if the latter the postpetiole with a short blunt or short tooth-like ventral process	35
29	Eyes relatively small, OI < 50	30
--	Smaller species; eyes relatively large, OI 50 or more	32
30	Propodeal spines long, 0.40 mm or longer in profile, distinctly longer than petiole, also strongly raised and divergent; TL 4.6-5.2 mm	.
.		West Africa & Congo Basin - greggi
--	Propodeal spines short, < 0.25 mm in profile, distinctly shorter than petiole	31
31	Dorsum of head with very dense cover of stout hairs, these mostly cylindrical; TL 4.0 mm	Zaïre - cestus
--	Dorsum of head with sparse cover of stout hairs, these conspicuously spatulate; TL 3.6 mm	.
..		Kenya - kenyensis
	Smaller species; eyes relatively large, OI 50 or more	.
32	Most or all of stout hairs on clypeus and dorsum of head increasing markedly in thickness from base to apex, often apex 2-3 times broader than base; TL 3.7-4.4 mm	.
.		West Africa & Congo Basin - pygmaeus
--	Most or all of stout hairs cylindrical or nearly so, not increasing from base to apex	33
33	Mesonotal and propodeal dorsa with very fine superficial low irregular, weak and wandering rugulae, feeble or faded out in places but never evenly spaced nor regularly longitudinal; spaces between fine rugulae densely and strongly reticulate-punctate; TL 3.3-3.6 mm	West Africa & Congo Basin - weissi
--	Mesonotal and propodeal dorsa with conspicuous strong, broad longitudinal rugae; spaces between rugae weakly sculptured or unsculptured, surface shining	34
34	Entire body exceptionally highly polished and very shiny; longitudinal rugae on posterior half of mesonotum and propodeum very broad, subsulcate and parallel, no junctions on propodeum; TL 3.2-3.5 mm	.
.		Nigeria & Cameroun - taylori
--	Dully shining and not obviously highly polished; longitudinal rugae tending to diverge and converge along their lengths or to be weakly wavy; with links on the propodeum; TL 3.3-4.5 mm	Benin - difficilis
	Either the subpetiolar complex simple, a rectangular or subrectangular lobe unlike above, or with a feebly prominent acute angle or small tooth posteroventrally, if the latter the postpetiole with a short blunt or short tooth-like ventral process	--
35	Dorsum of head with very short erect hairs; also usually with a sharp transition from the face to the occiput	36
--	Dorsum of head with conspicuous and quite dense hairs; smooth transition from face to occiput	37
36	Mesokatepisternum tooth long and acute, usually clearly visible in dorsal view; TL 3.3-3.7 mm	South Africa - micans
--	Mesokatepisternum tooth small and short, usually no more than a tubercle and not visible in dorsal view; TL 4.3-5.1 mm	.
..		eastern & southern Africa - intrudens (part, rugosus group)
	Dorsum of head with conspicuous and quite dense hairs; smooth transition from face to occiput	.
37	Larger species, HW > 1.10, PW > 0.90; dorsal surfaces finely but very strongly and closely reticulate-punctate; TL 4.5-5.1 mm	Zaïre - bequaerti
--	Smaller species, HW < 1.10, PW < 0.90	38
38	Lateral pronotum with irregular tuberculiform projections; TL 3.5-3.8 mm	South Africa - fricatidorsus
--	Lateral pronotum with series of denticles	39
39	Dorsal surfaces of mesonotum and propodeum extremely finely and very densely but more or less evenly longitudinally rugulose, rugulae so close together that spaces between have only 1-2 rows of punctures; TL 3.6-4.0 mm (note specimen shown smaller than type)	Cameroun - mckeyi
--	Dorsal surfaces of mesonotum and propodeum coarsely rugose, rugae predominantly longitudinal but with some strong cross-meshes, breaks or irregularities; rugae widely spaced; TL 3.7-4.4 mm	.
..		Pan-African forests - traegaordhi
..	Cataulacus species M This was collected by Room (1971) from one of his canopy samples at cocoa farms in Ghana, but seems to have escaped the attention of Bolton (1974a), so I cannot allocate a definite name.	..