The Ants of Africa Genus Camponotus subgenus Myrmotrema
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Primarily based on my translation of the work of Santschi (1915c), the Key surely is out of date, especially for eastern/southern Africa, but it still has obvious relevance.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?:

• auropubens Forel - from eastern/southern Africa - with strong puncturation on genae, long pubescence; and elongated alitrunk - key couplet 8.
• foraminosus Forel - widespread across Africa and into Arabia - gaster completely covered in pubescence - key couplet 13
• grandidieri Forel - from eastern/southern Africa with smaller puncturation on genae; very short or no pubescence, matt - key couplet 19.
• olivieri Forel - widespread across sub-Saharan Africa - gaster feebly sculptured, more or less shiny, pubescence generally very short and translucent - key couplet 27.
• robecchii Emery - from eastern/southern Africa - head and alitrunk more or less coloured not black; propodeum "tectiforme"- key couplet 38.

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

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© 2007, 2008, 2009, 2010, 2011, 2013, 2014 - Brian Taylor CBiol FSB FRES 11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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