SUBFAMILY PSEUDOMYRMECINAE - Genus Tetraponera
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The Ants of Africa SUBFAMILY PSEUDOMYRMECINAE - Genus Tetraponera |
| Contents - Pseudomyrmecinae |
Diagnostic Features - Slender elongate ants with relatively short legs. Clypeus sometimes produced into a spine or armed with a row of teeth or with a crenulate anterior margin. Either petiole alone with a ventral process or both segments without ventral processes.
F Smith's (1852) genus definition is at
.
[Smith, F. 1852. Descriptions of some hymenopterous insects captured in
India, with notes on their oeconomy, by Ezra T. Downes, Esq., who
presented them to the Honourable the East India Company. Ann. Mag.
Nat. Hist., (2) 9, 44-50]. Roger's (1863a) definition of Sima
is at 
.
All are arboreal species and very active, with characteristic rapid, jerky movements, and abrupt changes of direction. The previous Pachysima and Viticicola, were characterised because of their habit of living inside plant stems, sometimes as commensals, Pachysima in plants of the genus Barteria and tending large coccids on the plants. Hölldobler & Wilson (1990, page 535) describe the protection provided by Tetraponera (as Viticicola) tessmanni, which live only in stems of the liana, Vitex staudtii Guerkel; and by Tetraponera (as Pachysima) aethiops for Barteria fistulosa in Zaïre; they also list the incidence of Tetraponera ledouxi as a temporary parasite of Tetraponera anthracina (page 438, and Terron, 1969); and how one species, Tetraponera unidens (as nasuta), uniquely has a major caste with unknown functions (Terron (1971).
Earlier, Bernard (1952) remarked how all genus members inhabit hollow stems or dead wood and some support specific plants. From Africa, he reckoned there were some 30 species, with many still to be found.
Ward (1990: 449, 470) covered Tetraponera and confirmed earlier suggestions of the synonymy of Pachysima Emery and Viticicola Wheeler, also the non-African Parasima and Sima. The synonymy within Tetraponera is recognised also by Bolton (1994, 1995) but now Ward & Downie (2005), using DNA analysis appear to find differences that might substantiate the early genera as having merit.
Ward
& Downie (2004) made several analyses of the phylogenetic relations
within the Pseudomyrmecinae, of which Fig. 2 is an example. Morphological
features that they considered useful were (w = worker, q = queen) - the
angulate surface of the mandible above the trulleum (w), reduction in
mandibular teeth (w, q), and the narrow notchlike cleft on the distal
margin of the labrum (w, q). Non-African species listed are rufonigra
(India), pilosa (Borneo), grandidieri (Madagascar), allaborans
(Sri Lanka), morondaviensis (Madagascar), nigra (India)
and punctulata (Australia). The possible separation might be into
Pachysima for the rufonigra group; Tetraponera for
the T. nigra group (represented by the bottom couplet); and, Sima
Roger "for some fraction of the remaining species". I note that
Ward & Downie have separated caffra and natalensis,
whereas Bolton (1995) has caffra as a junior synonym of natalensis.
Ward (2006) continued his publication of studies of the genus mambers. In this latest part, he has established five monophyletic species groups covering all the Afrotropical and Malagasy species. These groups, for which he gave a key (adapted below), are rufonigra-group, ambigua-group, allaborans-group, grandidieri-group (Malagasy only] and natalensis-group. He also offered a revision of the T. ambigua-group. The paper can be seen in full - WARD, P.S. 2006: The ant genus Tetraponera in the Afrotropical region: synopsis of species groups and revision of the T. ambigua-group (Hymenoptera: Formicidae). Myrmecologische Nachrichten, 8, 119-130 http://antbase.org/ants/publications/21121/21121.pdf.
NOTE - I am not convinced that Ward's interpretation of the T. ambigua-group is correct. My species key, below, therefore, does not wholly support his revisions.
Ward designated one new species, Tetraponera parops Ward, from East Africa. He was hesitant to treat it as a new species but I think his designation is correct. However, I have specimens of Tetraponera unidens (Santschi) new status that have the lateral rough patches on the occiput used by Ward as a primary distinguishing character for parops. Ironically, Tetraponera parops actually seems close to the original description of ambigua. The further specimens from Tanzania support the separation of parops, which is distinctly smaller than the related species.
With fresh specimens from Gabon, I regard Tetraponera angolensis (Santschi) as a clearly distinct species.
Under the blanket species Tetraponera ambigua (Emery), Ward states "mesonotum weakly convex and not separated from anterior margin of propodeum by prominently raised metanotal spiracles". He appears unaware that the drawing of occidentalis by Stitz (1917) and the description of angolensis by Santschi (1930b) have these spiracles as prominent.
Tentatively, I have separated occidentalis (ambigua race erythraea var. occidentalis Stitz 1917: 336; Menozzi, 1934: 154, worker) from Algeria to subspecies of Tetraponera erythraea (Emery), as having a wider, oval postpetiole. Moreover, if occidentalis is a genuine subspecies of ambigua, the distribution in North Africa is strange; Menozzi (1934) wrote of the finding in southwest Algeria, plus his record of its collection in Libya (Cirenaica, by Professor L di Caporiacco) as being of the form typical of southern Africa. My co-author on Ants of Egypt, Mostafa Sharaf, collected a specimen that clearly shows the distinctiveness of the North African species.
Ward's drawing of ambigua shows roughened patches on the lateral occipitum and prominent erect hairs on the sides of the head. Santschi's description of angolensis has no roughened patches on the occipitum, no lateral erect hairs on the head, indeed very few erect hairs at all, a more rounded propodeum amd a lower petiole. It is distinctly smaller than the specimen in Ward's illustration, for which he gave no origin, and has the darkened posterior to the gaster mentioned by Santschi, plus the narrow frontal area shown by Santschi. There appear to be five distinct teeth on the mandible as opposed to four for Ward's ambigua (also in Arnold's note on rhodesiana). I feel justified in elevating angolensis to full species status - Tetraponera angolensis (Santschi).
As Ward states he examined syntype workers of angolensis and erythraea (but not occidentalis) I surmise that he followed the style of Bolton, in "lumping" the ancient "varieties, subspecies and stirps", mostly attributable to Forel and Santschi. The converse, however, is that, at least by Bolton, other species have been erected on quite small characteristics. My experience from reading all the source papers and with a wide range of fresh material is that Santschi was remarkably accurate in separating his "stirps" but was influenced by his mentor, Forel, and so was reluctant to designate new species.
I have mentioned Tetraponera unidens above, Ward (1990: 489) gave the "current nominal combination" T. ophthalmica Emery (1912: 98; from Cameroun), Tetraponera ophthalmica tenebrosa Santschi (1928: 61; from Zaïre) and Tetraponera ophthalmica unidens Santschi (1928: 60; from Zaïre); with the annnotation that he had examined specimens. I am confident from the original descriptions, my own drawings of a Nigerian specimen and fresh specimens from Cameroun, that it is correct to separate T. unidens off from Tetraponera ophthalmica (Emery).
Fresh specimens from Tanzania, have revealed Tetraponera bifoveolata (Mayr) to be like unidens in having a major worker. In both species this form has a curiously elongated head.
| 1 |  Large
species, HW > 1.70, distance between frontal carinae [MFC] > 0.35;
head with 3 distinct ocelli; petiole with prominent recurved
antero-ventral tooth aethiops & latifrons |
T. rufonigra-group |
| -- | Smaller, HW < 1.70, MFC < 0.25; head with 0-2 distinct ocelli, or, petiole with small simple antero-ventral tooth, or, both | 2 |
| 2 |  Pronotum
with sharp lateral margination, continuing backwards to propodeum and
petiole; overall appearance matt; mesonotum 2-3 times wider than long
and semicircular in dorsal view; petiole with notched posteroventral
marginandrei, angusta, anthracina, caffra [Ward list; ssp of natalensis], capensis, emacerata, ledouxi, lepida [BT], mocquerysi, monardi, natalensis, poultoni, prelli, schulthessi & triangularis |
[former Sima] T. natalensis-group |
| -- | Pronotum, propodeum and petiole usually with rounded lateral margins; if margin distinct then shiny; mesonotum about as long as wide and ovoid or subrectangular in dorsal view; petiole without a posteroventral notch | 3 |
| 3 | In full face view, large eyes with long axis angled
inwards anteriorly; upper half of mesosternum sparsely pubescent;
workers dimorphic with distinct soldier caste ambigua, bifoveolata [BT], encephala [BT], erythraea [BT], maculifrons [BT], ophthalmica, parops and unidens {BT} |
T. ambigua-group |
| -- |  In
full face view, eyes with long axis vertical; upper half of mesosternum
densely pubescent; workers monomorphicbraunsi, claveaui, clypeata, emeryi, gerdae, liengmei, mayri, penzigi, scotti, tessmanni & zavattarii |
T. allaborans-group |
Provisional key to workers of the Tetraponera
of Africa, derived in part from Arnold (1916: 170), who gave a key
to the then known species (as Sima); this is at
.
| ¤ | Species known only from the queen | Senegal - encephala |
| ¤ |  Species
known only from the queen; the profile, narrow gaster and overall size
suggest this may be the queen of
bifoveolata |
Tanzania - gerdae |
| ¤ | Species known only from the queen | Congo - lemoulti |
| ¤ | Species known only from the queen | Cameroun - mayri |
| 1 |  Thickset
species; frontal carinae set far apart; 3 ocelli; eyes relatively small |
2 |
| -- | Smaller, more slender, most with frontal carinae close together | 4 |
| 2 |  Small
species, TL 3.0-3.5 mm, eyes set forward of midlength of head |
(former subgenus Viticicola) - Congo Basin - tessmanni |
| -- | Large stout species, eye set towards rear of head | (former subgenus Pachysima) - 3 |
| 3 |  TL
9-10 mm, shining jet-black; petiole and postpetiole in dorsal view
ovoid; noticeable ventral processes on both the petiole and postpetiole
but these are simple triangles |
. |
| . | |
Panafrican (in Barteria) - aethiops |
| -- |  TL
7-8.5 mm, generally more slender; clypeus with a conspicuous fringe of
yellow ciliary bristles; petiole and postpetiole in dorsal view more
angular (rather than ovoid); petiole and postpetiole with rearward
hooked processes, quite pronounced on petiole; black and shining |
Cameroun & Congo Basin - latifrons |
| -- | Smaller, more slender, most with frontal carinae close together | -- |
| 4 | Pronotum
with distinct sharply margined anterior angles; 2 or 3 distinct ocelli |
(former subgenus Sima) 5 |
| -- |  Pronotum
with anterior angles rounded (may be laterally margined); ocelli
rudimentary or absent |
(former subgenus Tetraponera s.s.) 15 |
| -- | --Former Sima - usually with alitrunk and sometimes petiole dorsum with distinct lateral margins | -- |
| 5 | General colour black | 6 |
| -- | General colour no darker than brown | 10 |
| -- | Black to blackish species | -- |
| 6 | TL 4.5 mm; smallest of the group; similar to but smaller than mocquerysi with rectangular head longer than wide; colour primarily black but dull | Mozambique - andrei |
| -- | TL > 5 mm | 7 |
| 7 | TL > 5 mm < 7 mm; head with near straight occiput; propodeum decilivity laterally emarginate | 8 |
| -- | TL at least 7 mm; head with rounded occiput, at least the lateral angles; propodeum declivity laterally marginate | 9 |
| 8 |  TL
6.0 mm; head longer, about a quarter longer than wide, parallel sided;
posterior border more strongly impressed (prelli, mocquerysi
and anthracina being enlarged in the posterior one-third and
with convex sides). |
Panafrican - emacerata |
| -- | 
TL 6.0 mm; head rectangular (type apparently straighter sided than biozellata)
HL > HW; anterior margin of clypeus weakly arcuate with only fine
crenellation; body with yellowish pubescence, almost no erect hairs;
head and thorax densely and finely reticulate, semi-matt; entirely black
expect extremities |
. |
| . |  |
Panafrican - mocquerysi |
| -- | Colour darker - reddish-brown or brown | 12 |
| 9 | TL
7.1-7.9 mm; colour black, with extremities brown; cuticle smooth and not
finely puncturate as in anthracina; whitish pubescence on all
the body; on the head and thorax less dense but longer than on anthracina. |
. |
| . |  |
Cameroun & Central African Republic - ledouxi |
| -- |  TL
6.5-7.0 mm (9.3 mm for CRIN form); anterior margin of clypeus near
straight with 3-5 strong crenellations (teeth); abundant erect hairs all
over; colour dark red-brown to black, shiny |
. |
| . |  |
Congo & Nigeria - lepida stat. nov. |
| -- | TL 7.5 mm; black; erect whitish pilosity fine, absent on thorax and base of gaster; subopaque, very finely and densely reticulate, serrated puncturation on head and thorax; head as mocquerysi but eyes larger and with three ocelli; anterior of clypeus short rectangular lobe, margin weakly concave (lobe weakly indented in mocquerysi) | Equatorial Guinea & Nigeria - triangularis |
| -- | TL 7.5 mm; generally as triangularis but anterior margin of clypeus with five small teeth, the median tooth broader and blunt; only two small ocelli; petiole with sharp dorsal borders and ventral processes of a small anterior forward-directed tooth and a larger posterior backward-directed tooth | Uganda - poultoni |
 -- |
Colour no darker than brown | -- |
| 10 | Colour yellow or yellowish brown | 11 |
| -- | Colour darker - reddish-brown or brown | 12 |
| 11 | 
TL 4.8 mm; colour yellow, shiny almost transparent cuticle. Fine, dense
pubescence restricted to gaster. Eye length 0.39 mm (0.45 of HL). No or
only small ocelli. |
. |
| . |  |
Western Africa - Cameroun to Angola - ophthalmica |
| -- |  TL
6-8 mm; colour yellow or brownish yellow |
Tanzania southwards to the Cape of Good Hope - natalensis |
| -- | TL 9.0 mm; more robust than natalensis; head wider; alitrunk dorsum flatter; declivity of propodeum twice as long as dorsum; colour yellow-rust | Mozambique & Zimbabwe - schulthessi |
| -- | Colour darker - reddish-brown or brown | -- |
| 12 | Colour reddish-yellow | 13 |
| -- | 14 | |
| 13 |  TL
7 mm; dark reddish yellow |
South Africa - capensis |
| -- |  TL
ca 7.0 mm; narrow head, narrow petiole in dorsal view; anterior margin
of clypeus dentate; reddish ochreous |
Zimbabwe - angusta |
| 14 |  TL
6.5-7 mm; colour deep red-brown; shiny but with dense pubescence; head
near rectangular, eyes ca 50% of head length, 2 ocelli |
. |
| . |  |
West Africa & Congo Basin - anthracina |
| -- |  TL
5.6; alitrunk dorsum feebly convex without any impression of the
sutures; head and alitrunk densely puncturate and subopaque; brown but
with many areas lighter, notably the yellow-rust dorsum of the first
gaster segment |
Tanzania - prelli |
| -- |
Former subgenus Tetraponera - no more than anterior of pronotum with any lateral margination | - |
| 15 |  Dimorphic,
major TL 4.6-4.9 mm; minor TL 4.1-4.7 mm; head cylindrical, clypeus of
major (and queen) with distinctive elongated median anterior process;
both petiole and to a lesser extent, postpetiole distinctively low and
elongated; generally golden-yellow with at least part of the gaster
darker |
. |
| . |  |
West Africa & Congo Basin - (nasuta new status) unidens |
| -- | Most known only as monomorphic - note 2007 finding of a major for bifoveolata, anterior clypeus without prominent median process, although smaller processes may be present | 16 |
| 16 |  TL
3.6-4.0 mm; anterior margin of clypeus with two pairs of sharp processes
or teeth; black |
South Africa - clypeata |
| -- | Anterior margin with no or less than four teeth | 17 |
| 17 | 
TL 4-4.4 mm; clypeus with three teeth on anterior margin; if yellow head
and thorax shining; black with appendages reddish or lighter |
South Africa - braunsi |
| -- | Anterior clypeal margin with no or less than three teeth | 18 |
| 18 |  Colour
black or brown group - pear-shaped petiole |
19 |
| -- | Colour yellow-brown | 23 |
| -- | Dark brown to black | -- |
| 19 |  TL
11 mm |
Angola - monardi |
| -- | TL < 11 mm | 20 |
| 20 | Head elongated-rectangular | 21 |
| -- | Head elongated ovoid | 22 |
| 21 |  TL
3.4 mm; elongated head but eyes less than one-third of head length;
postpetiole rounded in dorsal view; postpetiole similar to the petiole
but more spherical in profile and dorsal views (latter is oval in penzigi).
Separable from liengmei and penzigi by its elongated
head and the postpetiole shape. |
Senegal & Gambia - claveaui |
| -- | TL 3.1-4.7 mm (continua smaller); clypeus angular in the middle, postpetiole ovoid in dorsal view; black | South and East Africa savannah - penzigi |
| -- |  TL
3.4-3.7 mm; head elongate-rectangular 1.5 X longer than wide; clypeus
with two longitudinal carinae ending in minute teeth; the eyes are
larger eyes than claveaui but still relatively small; very shiny
brown-black |
Mozambique - liengmei |
| 22 | Head oblong-oval HW 0.53 HL 0.69 shining black | Ethiopia - scotti |
| -- | TL
4.0-4.5 mm; petiole distinctly domed; black |
Ethiopia - zavattarii |
| -- |
Yellow or reddish yellow | -- |
| 23 | TL 4.5 mm; pronotum not margined, clypeus with five teeth on the anterior margin, the outer two smallest; eyes near 1/3 of head length; | South Africa - emeryi |
| -- | Pronotum at least laterally margined; yellow or reddish yellow, head and thorax not smooth and shining | 24 |
| 24 | Clypeus emarginate medianly, evenly convex | 25 |
| -- | Clypeus not emarginate medianly; rectangular and/or with a feebly tridentate margin | 26 |
| 25 |  TL
3.8-4.2 mm; with abundant pubescence, especially so on the gaster;
reddish yellow |
East Africa north from Mozambique - bifoveolata |
| . |  |
major of bifoveolata - first record |
| -- |  TL
ca 6 mm; mesonotum with strong sutures all around; mesonotum shallowly
domed; petiole relatively more domed; apparently without significant
pubescence |
Djibouti & Egypt - maculifrons |
| -- |  TL
ca 4 mm; without significant pubescence; posterior of gaster darkened |
Angola & Gabon - angolensis |
| -- | Clypeus not emarginate medianly; rectangular and/or with a feebly tridentate margin | -- |
| 26 |  TL
4.5 mm; anterior margin of clypeus produced medianly into a rectangular
lobe; frontal carinae set quite far apart; relatively abundant erect
pilosity |
. |
| . |  |
Southern & Eastern Africa - ambigua |
| . | Anterior margin of clypeus not lobed, feebly tridentate in the minor and distinctly so in the major | ambigua ssp rhodesiana |
| -- | TL < 4.5 mm; frontal carinae set quite close together; postpetiole ovoid; erect pilosity restricted; | 27 |
| 27 |  TL
4.0 mm; mesonotum with a raised angular profile; eyes closer to
posterior border of head; piligerous punctures on head stronger giving a
coarse uneven appearance; femora with a brownish dorsal edge |
Yemen (Aden) & Algeria - erythraea |
| -- | TL
ca 3 mm; mesonotum with concave profile; occiput with lateral patches of
short bristly pilosity, pronotum with paired erect hairs |
East Africa - parops |
 |
© 2007, 2008 - Brian Taylor CBiol
FIBiol FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K. |
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