The Ants of
Africa Genus Camponotus subgenus Myrmotrema |
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Genus Camponotus |
Subgenus definition - Section 11 Myrmotrema Forel (1912i: 91) - simply had - "group foraminosus and relatives; characterised by the foraminous or carious head of both major and minor".
Head as in Orthonotomyrmex, major very broad posteriorly, minor trapezoidal, broadened posteriorly; thorax with or without dorsal notch; in major and queen anterior of head covered with deep round pits; apparently termitophages, 32 species from sub-Saharan Africa.
Primarily based on my translation of the work of Santschi (1915c), the Key surely is out of date, especially for eastern/southern Africa, but it still has obvious relevance. I have used modern nomenclature (as in Bolton, 1995), added the species argus and made comments.
Bernard (1952) gave the definition "Section 11 Myrmotrema Forel - small to medium sized, gaster matt, with or without dense coloured hairs, antenna more or less deformed, apparently termitophages, 32 species from sub-Saharan Africa". Bolton (1995) also has 32 names of species in the subgenus.
Of his Key, Santschi noted - there is insufficient material to establish purely phylogenetic characters so I have used practical features.
Provisionally, he recognized five species within the foraminosus group, with more or less cylindrical tibiae and without a row of "piquants" = spike-like hairs?:
Species post-dating the Santschi key are -
avius
from Zimbabwe & Angola
monardi
from Angola - close to grandidieri
and tilhoi
from Chad - seemingly close to olivieri.
Key to members of the subgenus Myrmotrema
1 | Tibiae cylindrical or not strongly compressed, without a line of spurs; scapes cylindrical or slightly flattened | 2 |
-- | Tibiae prismatic or generally channelled; scapes always flattened; all are black | 42 |
2 | Head and alitrunk always black | 3 |
-- | Head and alitrunk otherwise coloured | 36 |
3 | TL 5-8 mm; gaster segments largely bordered with yellow; long golden pubescence and abundant, slender, very long, yellow silky hairs | Saõ Thomé - aurofasciatus |
-- | Gaster black or brown black or very narrowly bordered with yellow; silky hairs shorter | 4 |
4 | Propodeum with dorsum very compressed so comprising little more than the declivity | 4A |
-- | Propodeum dorsum not compressed | 5 |
4A | Worker only known TL 4.5 mm | Zaïre - argus |
-- | TL 9.6-11.6 mm; pilosity whitish, thick and pointed; distinctive pattern on the gaster | . |
. | Media/minor | South Africa - postoculatus |
5 | Propodeum dorsum rectangular, slightly convex and weakly bordered | 6 |
-- | Propodeum dorsum narrower especially posteriorly | 7 |
- | Propodeum dorsum rectangular, slightly convex and weakly bordered | - |
6 | Stocky,
black, antennae red; propodeum dorsum flat; TL 5.3-6.3 mm; major not
before found is larger; the sharply angled propodeum profile is
distinctive |
|
. | Minor | East Africa - galla |
-- | TL 3.5-6.6 mm; more slender; matt and entirely punctate; tarsi and antennae red, posterior borders of gaster yellow gold | Guinea & Ivory Coast - orthodoxus |
-- | Description inadequate on structure but - erect pilosity long yellowish but scattered, gaster with greyish moderate pubescence; overall black; base of scape, apices of anterior and mid tarsi, spicules and spurs reddish; TL 6.9-9.2 mm | Malawi - lamborni |
- | Propodeum dorsum narrow especially posteriorly | - |
7 | Genae of majors with confluent hair pits, which are larger than spaces between; the arising hairs long and abundant, similar to those on the gaster | 8 - auropubens and ssps |
-- | Genae of majors with shallow hair pits that are smaller than the spaces, and with only very short or no hairs | 12 |
8 | Gaster with a clear median glabrous line | 9 |
-- | Gaster with no more than a very fine glabrous line [the attribution to foraminosus seems dubious]; TL 5.0-8.7 mm | Aldabra I. - foraminosus ssp aldabrensis |
9 | Genae with partially raised pubescence, as long as width of scape extremity | 10 |
-- | Genae pubescence short and decumbent | 11 |
10 | Tibiae blackish brown; propodeal dorsum slightly convex; TL to 9.0 mm | Mozambique- auropubens |
-- | Tibiae rust; propodeal
dorsum flat; mesonotum of female matt; TL 5.5-9.5 mm Queen shown |
South Africa - auropubens ssp absalon |
11 | Major, pilosity golden; tibiae rust | . |
. | Minor | south eastern Africa - auropubens ssp jacob |
-- | Pilosity silver; female with shiny pronotum | Angola - auropubens ssp argentopubens |
11A | Gynandromorph major | south eastern Africa - monardi |
Genae of majors with shallow hair pits that are smaller than the spaces, and with only very short or no hairs | - | |
12 | Gaster with fine, long pubescence, generally cloaking the sculpture; without median glabrous line | 13 |
-- | Pubescence more translucent/sparser | 18 |
13 | Clypeus of major without a carina; erect silky hairs fine generally same colour as pubescence | 14 - foraminosus and ssps |
-- | Clypeus of major with a carina; erect silky hairs slender, abundant clear yellow; TL 6-8.2 mm | . |
. | Minor | north-east Africa west to Chad - rhamses |
14 | Very matt appearance; head and alitrunk glabrous | Ethiopia - foraminosus ssp honorus |
Head and alitrunk quite pubescent | 15 | |
15 | Gaster with greyish yellow pubescence | 16 |
-- | Gaster with yellow or brassy red pubescence | 17 |
16 | Dorsum of gaster with dense pubescence; TL major 7-8 mm | . |
. | West Africa & Congo Basin - foraminosus | |
-- | Pubescence less dense | Nigeria, Calabar - foraminosus ssp deductus |
-- | Congo - foraminosus ssp flavus | |
17 | Gaster with golden yellow pubescence | East Africa - foraminosus ssp chrysogaster |
-- | Gaster with brassy red pubescence [in the accompanying text, Santschi had this as foraminosus var. annobonensis; if he was right it seems more likely it is a foraminosus ssp] | Annobon I. - perrisii ssp insularis |
Pubescence more translucent/sparser | -- | |
18 | Gaster matt, densely puncturate; pubescence generally quite long | 19 |
-- | Gaster shiny, or shiny matt; largely finely reticulate or shagreened; pubescence generally quite short and spaced out | 26 |
19 | Gaster dorsum with a median glabrous line; sometimes less obvious on smaller morphs | 20 |
-- | Gaster dorsum without median glabrous line | 23 |
20 | Major with scapes not surpassing occiput by more than the length of funiculus segment 1. | 21 |
-- | Scapes longer | 22 |
21 | Tibiae and tarsi rust coloured; pubescence distinct on clypeus and genae; TL 5.0-8.2 mm | Madagascar - grandidieri |
-- | Tibiae and tarsi black or black brown; gaster more elongated; glabrous line less obvious | Grand Comoro I. - grandidieri ssp comorensis |
22 | Tibiae and tarsi more or less rust coloured; glabrous line clear | Madagascar; Diego Suarez, Mozambique - grandidieri ssp atrabilis |
-- | Tibiae and tarsi black; head of minors more elongated; glabrous line less obvious | South Africa - grandidieri ssp mendax |
23 | Propodeum dorsum triangular, very narrow posteriorly; antennae and lower legs red | 24 |
-- | Propodeum dorsum insignificantly narrowed posteriorly | 25 |
24 | Propodeum dorsum slightly convex in profile; pubescence slight, as with the erect hairs | Somalia - grandidieri ssp ruspolii |
-- | Propodeum dorsum straight-sided; pilosity and pubescence more abundant | South Africa - grandidieri ssp rollei |
25 | Major TL 7.5 mm; propodeal dorsum as long as declivity; alitrunk less convex; golden pubescence quite abundant; silky hairs slim white and blunt; very matt | . |
. | Minor TL 5.5 mm | Angola - benguelensis |
-- | Major; TL 4.5-7 mm; clypeus
without a carina; tibiae without
setae; propodeum narrow, rectilinear in profile, dorsum slightly
shorter than declivity; erect hairs sparse whitish; pubescence on the
body bright whitish-yellow; overall matt black, mandibles, tibia &
tarsi reddish, femora brown |
. |
. | Minor | Zaire, Katanga - confluens |
-- | Propodeal dorsum shorter than declivity; pubescence white, short and translucent; silky hairs fine and quite short; semi-matt, genae shiny; TL 4.4-7.35 mm | . |
. | Type Major | . |
. | Nigeria - haereticus | |
Gaster shiny, or shiny matt; largely finely reticulate or shagreened; pubescence generally quite short and spaced out | -- | |
26 | Distinct angle at junction of dorsum and declivity of propodeum, sometimes with rounded edge; no glabrous line on gaster | 27 - olivieri and ssps. |
-- | Junction of propodeum dorsum and declivity a rounded curve; gaster with distinct medial glabrous line | 35 |
27 | Scapes entirely black; TL 6.0-8.5 mm | 27A |
-- | Erect hairs white; base of scapes and funiculus segment 1 rust coloured | 28 |
27A | Erect hairs and pubescence golden; TL 6.0-8.5 mm | Angola - olivieri ssp concordia |
27B | Pilosity whitish, fine
and sharp, moderately abundant; worker TL 7.5 -8.0 mm; cf olivieri alitrunk
more robust, mesonotum more raised, propodeal angle more rounded,
propodeal dorsum straight but transversely rounded, declivity concave;
overall black, scape entirely black except condyle, funiculus, condyle,
mandibles anterior of head, posterior tarsi brown; densely matt except
feebly shiny dorsal pronotum Note apparently identical to tilhoi (below) |
Zaïre - atriscapus |
27C | Major: Pilosity whitish, fine and sharp, moderately abundant; worker TL 7.5 -8.0 mm | . |
. | Minor | Chad - tilhoi |
28 | Gaster uniformly shiny | 29 |
-- | Gaster punctate and matt posteriorly, reticulate and quite shiny anteriorly; alitrunk with golden translucent pubescence | Zaïre - olivieri ssp osiris |
28B | Major | . |
. | Minor | southern Africa - avius |
29 |
Alitrunk
covered with dense pubescence, more so than gaster |
30 |
-- | Pubescence no more dense on alitrunk than gaster | 31 |
30 | Gaster and lower legs brown or black brown; major TL 7.5-8.0 mm | Angola & Gabon - olivieri |
-- | Part of alitrunk and base of gaster brown | East Africa - olivieri ssp moshianus |
-- | Gaster black, size larger - Congo | olivieri ssp sorptus |
31 | Erect pilosity on gaster as fine as the pubescence | olivieri ssp tenuipilis |
-- | Erect pilosity on gaster more slender than pubescence | 32 |
32 | Overall shinier, with sparse pilosity, gaster with very sparse pubescence; translucent and short; propodeal angle very marked | Angola & Gabon - olivieri ssp lemma |
-- | Pubescence on gaster denser | 33 |
33 | More robust, scale blunter, lower legs black, pubescence yellowish | Mozambique, Delagoa - olivieri ssp delagoensis |
-- | More narrow, scale sharper; lower legs brown, pubescence white | 34 |
34 | Erect pilosity blunt and slender; TL 4.3-6.0 mm | . |
. | Minor | Mozambique, Delagoa - tauricollis |
-- | Erect pilosity fine and sharp | Cameroun - olivieri ssp pax |
35 | Alitrunk short, vaulted, propodeum rounded; gaster very shiny; pubescence short, translucent, lower legs black | South Africa - olivieri ssp infelix |
-- | Alitrunk elongated, slightly convex; propodeum rounded; gaster shiny; lower leg rust coloured | Aldabra - olivieri ssp freyeri |
Head and alitrunk other than black | -- | |
36 | Promesonotum strongly convex and raised higher than propodeum; latter with a flat dorsum | 37 |
-- | Promesonotum no more than slightly higher than propodeum | 38 |
37 | TL 4.2-4.7 mm; generally brown-red, with darker areas | Ethiopia, Senegal - ilgii |
-- | TL ca 6 mm; ferruginous-yellow, upper head and propodeum brownish | . |
. | Ethiopia & Sudan - diplopunctatus | |
38 | Head as narrow as the alitrunk; notably longer than wide; alitrunk and gaster elongated, yellow; TL 4.5-7.5 mm | Somalia - bottegoi |
-- | Head wider than alitrunk, more robust | 39 - robecchii and ssps. |
39 | Propodeum "tectiforme", slightly lower than pronotum | 40 |
-- | Alitrunk profile feebly convex, no break at metanotal groove | 41 |
40 | Propodeum angular; colour dark brown red; posterior third of gaster and sides of alitrunk blackish; femora and antennae yellow red; TL 4-5.8 mm | . |
. | Somalia & Tanzania - robecchii | |
-- | Propodeum rounded, colour red yellow, gaster black | Zimbabwe - robecchii ssp rhodesiana |
41 | Colour reddish, base of gaster yellow, posterior of gaster black brown; major TL 7-9 mm | East Africa & Indian Ocean Is - troglodytes |
-- | Colour reddish, each gastral segment with brown border [note: this seems to be wrongly given as ssp of foraminosus in Bolton (1995)] | Angola - troglodytes ssp cuitensis |
-- | Gaster entirely yellow red in female | Ethiopia - troglodytes ssp abyssinica |
Tibiae prismatic or generally channelled; scapes always flattened | -- | |
42 | Propodeum without tubercles | 43 |
-- | Propodeum bituberculate; TL 9.0 mm; matt black, extremities reddish | West Africa - bituberculatus |
43 | Scape dilated, but the apex less than four times as wide as the base | 44 |
-- | Scape foliate, apex expanded to four times the basal width; TL 8 mm; colour as bituberculatus but whole of mandibles and base of scape reddish | West Africa - compressiscapus |
44 | Clypeus of major and minors near trapezoidal [NOTE the image in Wheeler (1922) of perrisii jucundus shows the clypeus as trapezoidal - may be the original key has the numbers transposed!] | 44 |
-- | Clypeus of major near rectangular | 46 |
45 | Major
with distinct pits on genae; pubescence sparse but distinctly
yellowish, erect hairs numerous, quite long and yellowish (type minor
shown here) |
East Africa - puberulus |
-- | Major with only indistinct pits on genae; TL 6.0 mm; matt, black, with extremities of tarsi and mandibles reddish | . |
. | Minor | western Africa - bayeri |
46 | Erect hairs translucent brown or blackish | 47 |
-- | Erect hairs clear, white or yellowish | 48 |
47 | Pubescence very sparse, and extremely short; TL 6.3-7.0 mm; black, opaque and densely punctate | eastern Africa - carbo |
-- | Pubescence short but distinct; TL 7.4-10 mm | western Africa - carbo ssp occidentalis |
48 | Major, tibiae only feebly prismatic, with slight channeling; TL 8.0 mm; matt black | . |
. | Minor | Angola, Benguela, Cameroun - crucheti |
-- | Tibiae with distinct channeled and prismatic tibiae; all generally black amd matt; base of scape and apex of mandibles reddish | 49 - perrisii and ssps |
49 | Propodeum with rounded angle | 50 |
-- | Propodeum with well marked but slightly diffuse angle | 51 |
50 | Scape surpassing occipitum by more than its width in major; tibial channeling less pronounced; TL 10-11 mm; with whitish erect hairs | Angola - perrisii |
-- | Scape longer; tibiae strongly channelled; longer, TL 12 mm | western Africa - perrisii ssp. nigeriensis |
51 | Gaster covered with quite dense yellow pubescence; TL 10-11 mm | Congo - perrisii ssp. jucundus |
-- | Gaster with shorter, more spaced out, whitish pubescence; shorter | Congo - perrisii ssp. grandior |
Genus page |
© 2007, 2008, 2009, 2010, 2011, 2013, 2014 - Brian
Taylor
CBiol
FSB FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K. |
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