| The Ants of Africa SUBFAMILY MYRMICINAE - Genus Cardiocondyla |
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| Contents - Myrmicinae - MYRMICINAE Introduction |
In Tribe FORMICOXENINI.
Diagnostic Features - Eyes well developed and sited forward of the front of the midlength of the head. Antennae 12-segmented, with a three-segmented club, and the scapes short, failing to reach the posterior margin of the head. The lateral portions of the clypeus project forwards over the basal margins of the mandibles. Sculpture usually of fine dense puncturation on the head and alitrunk, but none on the gaster. Sparse pubescence but erect setae only on the anterior clypeal margin. Alitrunk with the promesonotal suture absent and the metanotal groove impressed. Propodeum with a pair of teeth or spines. Petiole with a long peduncle in front; in dorsal view the post-petiole is very broad. Middle and hind tibiae without spurs.
Emery's (1869b) genus description is at
.
Arnold (1916) gave a genus description, this is at
.
Revised by Bolton (1982). All small to minute ants which nest in soil,
usually at the bases of trees, or in compressed leaf litter. Belshaw &
Bolton (1994) noted that three species are known from Ghana. The full text
of Bolton's revision can be seen at -
Bolton,
B. 1982. Afrotropical species of the myrmicine ant genera Cardiocondyla,
Leptothorax, Melissotarsus, Messor and Cataulacus
(Formicidae). Bull.
Brit. Mus. (Nat. Hist.) Entomol. 45: 307-370.
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Rigato (2002) described three new species from sub-Saharan Africa. Two, longinoda and luciae were from Tanzania and one, yorubae, came from Nigeria. The latter however, seems to differ little from emery. Moreover, it exactly matches the specimen I drew from Nigeria and collected at some time by Barry Bolton. Rigato, who was supplied with the specimens he described by Bolton, makes no mention of sighting either emery from any other source. I, therefore, tentatively regard yorubae as a junior synonym of emeryi.
In contrast to Rigato, Seifert (2003) made an extremely detailed and sophisticated study of primarily Holarctic Cardiocondyla. Although published later, this study surely, at least, overlaps that by Rigato. Seifert included all but two of the species in Bolton (1982) and transferred globinodis and badonei from wroughtoni to venustula. The latter thus was added to the list from sub-Saharan Africa, as is C. mauritanica (a Zimbabwe record)
Key to species known from Africa (derived from Bolton, 1982, and revised to incorporate Rigato, 2002):
| ¤ | Queen only known; dark brown to blackish brown | Nigeria - zoserka |
| 1 | Alitrunk
dorsum without metanotal groove or impression; propodeum unarmed; TL 2.7
mm; yellow with silvery pubescence |
Angola - monardi |
| -- | Alitrunk
dorsum with distinct metanotal groove; propodeum sharply angulate or
bispinose |
2 |
| 2 | In
full face view scapes distinctly exceeding occipital margin; TL 2.5 mm;
bright ferruginous |
Sudan - as a junior synonym of fajumensis - nilotica |
| -- | Scapes not exceeding occipital margin | 3 |
| 3 | Dorsal surfaces of head and alitrunk smooth and glossy, unsculptured except for minute puncturation on head; TL 1.8 mm; uniform glossy blackish brown | Ghana - sekhemka |
| -- | Dorsal surfaces of head, alitrunk or both finely and densely sculptured | 4 |
| 4 | Dorsum of gaster distinctly finely shagreened, not smoother than head or alitrunk | 5 |
| -- | Dorsum of gaster not shagreened, smoother than head or alitrunk | 6 |
| 5 | Petiole
with elongate node, 1.5 X longer than wide, with a low profile; TL 2.1
mm; scape relatively long SI 97-100; testaceous yellow |
Tanzania - longinoda |
| -- | Petiole
with shorter node, less than 1.5 X longer than wide, with a domed
profile; TL 2.1 mm; scape relatively long SI 90; reddish brown, gaster
duller, antennal club darker |
Tanzania - luciae |
| 6 | Propodeum
in absolute profile bluntly angulate to bidenticulate, never with a pair
of strong teeth or spines which are longer than their basal width in
profile; scapes relatively long; TL 2.0-2.6 mm; medium brown to
blackish-brown |
Pan-African - shuckardi |
| -- | Propodeum in profile strongly bidentate to bispinose; scapes relatively short | 7 |
| 7 | In
profile alitrunk with propodeal dorsum approximately flat behind the
propodeal groove, more or less level with the promesonotal dorsum, and
not sloping gradually down to the spines; TL 1.9 mm; alitrunk
medium-brown, appendages lighter, head dorsally and gaster
blackish-brown to black |
Cameroun - weserka |
| -- | Alitrunk dorsum convex behind metanotal groove, then sloping down to spines | 8 |
| 8 | In
profile alitrunk with sharp drop into metanotal groove; TL 1.6-1.9 mm;
head, alitrunk and appendages yellow to yellowish brown but gaster
variable from same colour to much darker |
Pantropical tramp - wroughtonii |
| In profile alitrunk with even curve into metanotal groove | 9 | |
| 9 | Pronotal
corners bluntly but conspicuously angular in dorsal view; propodeal
spines relatively long and slender; TL 1.80-1.81 mm; light brownish
yellow; sides of first gastral tergite a rich darker brown |
West Africa - neferka |
| -- | Pronotal
corners rounded in dorsal view, propodeal spines relatively short and
stout; TL 1.8 mm; colour orange with gaster and antennal club brown |
Pantropical tramp - emeryi (yorubae) |
|
Key following Seifert (2003)
CL - HL on median line; CS = median of CW+CL; FRS = distance of frontal carinae immediately caudal of the posterior intersection points betwwen the frontal cariane and the dorsal lamellae of the torus; PPH = maximum postpetiole height; mesosoma used rather than alitrunk. The scale on his illustrations of the main worker is 213 µm. I find that for a field worker or, indeed, anyone without very high quality equipment, his key as it stands is not easy too use. |
||
| 1 | Postpetiole
with prominent anteroventral corners; seen from a frontal angle the
anterior margin is concave |
2 |
| -- | Postpetiole
without prominent anteroventral corners |
5 |
| 2 | Head short CL/HW < 1.19 | 3 |
| -- | Head longer, frons narrower | 4 |
| 3 | First
and following gaster tergites not equally dark [In profile alitrunk with
sharp drop into metanotal groove; TL 1.6-1.9 mm; head, alitrunk and
appendages yellow to yellowish brown but gaster variable from same
colour to much darker] |
cosmopolitan tramp; Tanzania & Somalia - wroughtonii |
| -- | First
and following gaster tergites equally dark |
cosmopolitan tramp but the single Kenya record (worker, Kaijado, x.1999) may be an error - obscurior |
| 4 | Alitrunk
(mesosoma) profile relatively flat, metanotal groove shallow, pronotum
with more rounded shoulders [In profile alitrunk with propodeal dorsum
approximately flat behind the propodeal groove, more or less level with
the promesonotal dorsum, and not sloping gradually down to the spines;
TL 1.9 mm; alitrunk medium-brown, appendages lighter, head dorsally and
gaster blackish-brown to black] |
Cameroun - weserka |
| -- | Alitrunk
(mesosoma) and propodeum profile slightly convex, metanotal groove
distinct, pronotum with well-developed shoulders, each with a rounded
angle of 120° [Pronotal corners bluntly but conspicuously angular
in dorsal view; propodeal spines relatively long and slender; TL
1.80-1.81 mm; light brownish yellow; sides of first gastral tergite a
rich darker brown] |
West Africa - neferka |
| 5 | FRS/PPH
< 0.722; small CS 386-457 µm; head elongated CL/CW 1.19-1.27;
postpetiole as high as petiole with conspicuous ventral bulge; propodeal
spines moderately long |
widespread tramp - emeryi |
| . | dark
form apparently common in Congo Basin |
emeryi |
| -- | FRS/PPH > 0.722 | 6 |
| 6 | Propodeal spines in lateral view with blunt angles of 95-120°; sides of postpetiole in dorsal view always rounded convex; promesonotal and anterior propodeal profiles forming shallowly convex curvatures to give a wide metanotal depression | shuckardi-group - 7 |
| -- | Propodeal
spines in lateral view with smaller angles of 60-95°; sides of
postpetiole in dorsal view more angular; promesonotal and anterior
propodeal profiles not forming shallowly convex curvatures, so metanotal
depression weak or absent |
Zimbabwe (once; gyne only, vii.1995) - nuda-group - mauritanica |
| 7 | Scape
relatively short SL/CS 0.79-0.84; postpetiole wider; metanotal
depression shallower; unicolorous medium to dark brown |
southern East Africa - shuckardi |
| -- | Scape longer SL/CS 0.81-0.87; postpetiole narrower; metanotal depression deeper | 8 |
| 8 | Eye
larger; all over dark brown, smaller CS 467-572 µm |
south-eastern Africa - venustula |
| -- | Eye
smaller; head and alitrunk variably yellowish, gaster dark to
blackish-brown, larger CS 556-633 µm |
Sudan (as nilotica) - fajumensis |
| MYRMICINAE Introduction | © 2007 - Brian Taylor CBiol
FIBiol FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K. |
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