SUBFAMILY MYRMICINAE - Genus Cataulacus
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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
.
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 (used by Bolton, 1974a).centrurus
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 & Uganda - egenus |
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 Kemya - 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 |
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; 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 numerous long stout hairs; TL 3.8-5.2 mm |
. |
| .. |  |
eastern & southern Africa - wissmannii |
| -- |  Dorsum
of head with few and inconspicuous short stubbly hairs; TL 4.3-5.1 mm |
. |
| . |  |
eastern & southern Africa - intrudens (part, intrudens group) |
| . | 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 - 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 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 MThis 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. |
.. |
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MYRMICINAE Introduction | © 2007, 2008 - Brian Taylor CBiol
FIBiol FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K. |
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