The Ants of Africa
Genus Tetramorium species-groups - Part 5
Tetramorium Introduction

Species groups
Part 5 - former Tetramorium (Tetramorium)
species with short antennal scapes, larger eyes and nodiform petioles

return to start

12-segmented antennae (Tetramorium)
{12-segmented antenna}
Scape index < 100 (scape shorter than head width; usually does not reach occiput)
TD4 Eyes larger > 0.20 X HW, wider than maximum width of scape
Petiole not squamiform
SUB1 Lamellate appendage of sting spatulate or linear
Otherwise next stage of key next sub-division
grassii-group -
Complex-1 Smooth mandibles; propodeal spines short; petiole node narrowed so no distinct dorsum
63 Propodeal node rounded in profile; pronotal dorsum mostly smooth; TL 3.0 (3.6 mm?); brownish rusty-red, head and gaster darker
{Tetramorium titus}
. .
. {Tetramorium titus} Tetramorium titus South Africa
63 Propodeal node sharp-edged in profile; pronotal dorsum rugulose; TL 3.7-4.3 mm; uniform dark brown
{Tetramorium vexator}
. .
. {Tetramorium vexator} Tetramorium vexator South Africa
Complex-2 Striate mandibles; propodeal spines relatively long; petiole node not narrowed dorsally
128 Erect hairs on dorsum of body plumose; TL 3.6-3.8 mm; uniform brown, appendages lighter
{Tetramorium plumosum}
. .
. {Tetramorium plumosum} Tetramorium plumosum Swaziland
130 Erect hairs on dorsum of body fine and acute apically; TL 3.0-4.1 mm; uniform brown, variable
{Tetramorium grassii}
. .
. {Tetramorium grassii} Tetramorium grassii southern Africa
130 Erect hairs on dorsum of body coarse, stout and blunt; TL 3.0-3.6 mm; uniform yellowish brown
{Tetramorium regulare}
. .
. {Tetramorium regulare} Tetramorium regulare South Africa
return to start of key stage

SUB2 Lamellate appendage of sting dentiform, triangular or pennant-shaped
SUB3 Frontal carinae short, ending ahead of posterior margin of eyes
Otherwise next stage of key sub-section
Propodeum with a pair of small teeth or denticles
Otherwise next stage of key next species group
ungrouped - former Atopula) -
61 Elongated head, with short scapes; propodeum with transverse rugulae; TL 4.4-4.6 mm
{Tetramorium nodiferum}
. .
. Tetramorium nodiferum Tetramorium nodiferum Ghana, Cameroun, Kenya
Anterior clypeal margin with median deep broad indentation or ventral head with ammochaete hairs or both; all but one with ammochaete hairs; all relatively large, TL > 3.7 mm
Otherwise next stage of key next species group
solidum-group -
peringueyi-complex With coat of abundant short erect hairs all over body and legs
94 Without ammochaete hairs; antennal scapes without erect hairs; TL 3.7-3.9 mm; brown but alitrunk more orange
{Tetramorium dichroum}
. .
. Tetramorium dichroum
Tetramorium dichroum South Africa
94 Antennal scapes with erect hairs as on hind tibiae; TL 4.4-5.7 mm; orange-red to deep red
{Tetramorium peringueyi}
. .
. {Tetramorium peringueyi} Tetramorium peringueyi Botswana
setuliferum-complex No erect hairs on dorsal surfaces of body but bizarre appressed pilosity
31 With dense long strap-like silvery hairs, overlapping on vertex and alitrunk; TL 5.1-6.0 mm; uniform red
Tetramorium galoasanum
Tetramorium galoasanum Congo
- Appressed hairs sparse and spaced out, not strap-like or overlapping
32 In profile gaster with anterior lower corner of first gastral tergite developed so as to overhang sternite; TL 4.4-6.0 mm; uniform dull red
{Tetramorium setuliferum}
. .
. {Tetramorium setuliferum} Tetramorium setuliferum East and southern Africa
32 Without lobe on first gastral tergite; silvery hairs quite sparse; TL 3.9-4.6 mm; dull blackish brown to black; appendages reddish-brown
{Tetramorium clunum}
. .
. {Tetramorium clunum} Tetramorium clunum South Africa
solidum-complex No erect hairs on body (a few on the alitrunk in one species), well developed psammophore, finer sculpturation
115 With a few hairs on dorsal alitrunk; TL 4.1-5.1 mm; dark brown or blackish-brown
{Tetramorium solidum}
. .
. {Teramorium solidum} Tetramorium solidum South Africa
- No erect hairs on dorsum of alitrunk, pedicel or gaster
28 Without propodeal spines; TL 5.3-5.8 mm; black or blackish-brown
{Tetramorium jordani}
. .
. Tetramorium jordani
Tetramorium jordani southern Africa
- Propodeum with spines
33 Distinctive distorted pedicel segments; TL 5.0-5.3 mm; deep reddish-brown to blackish-brown
{Tetramorium grandinode}
. .
. {Tetramorium grandinode} Tetramorium grandinode South Africa
- Petiole and postpetiole normal for group
- Colour orange-red to darker red
35 Propodeal spines very short, broad triangles; TL 5.0-5.7 mm
{Tetramorium glabratum}
. .
. {Tetramorium glabratum} Tetramorium glabratum southern Africa
35 Propodeal spines long, much longer than basal width; TL 4.0-5.1 mm
{Tetramorium rufescens}
. .
. {Tetramorium rufescens} Tetramorium rufescens Namibia
- Colour brown or darker
36 Anterior clypeal margin with broad concave median emargination; TL 4.4-5.3 mm
{Tetramorium signatum}
. .
. {Tetramorium signatum} Tetramorium signatum southern Africa
37 Anterior clypeal margin with shallow concave median emargination; head narrowing anteriorly; TL 4.8-5.4 mm; blackish-brown
{Tetramorium barbigerum}
. .
. {Tetramorium barbigerum} Tetramorium barbigerum Namibia
37 Anterior clypeal margin with shallow concave median emargination; head parallel-sided; TL 3.8-4.1 mm
{Tetramorium pogonion}
. .
. {Tetramorium pogonion} Tetramorium pogonion Namibia
Anterior clypeal margin entire and ventral head without ammochaete hairs
Hairs on dorsal alitrunk and/or first gastral tergite short, stout and blunt apically; frontal carinae at most feeble; TL range 2.0-2.8 mm
Otherwise next stage of key next species group
simillimum-group - poweri-complex -
- Wholly without frontal carinae or scrobes
108 Very small eyes; TL 2.2-2.2 mm; uniform yellowish-brown or light brown
Tetramorium pauper
Tetramorium pauper Kenya
181 Eyes with 6-8 ommatidia in longest row; TL 2.6-2.8 mm; uniform dull yellowish-brown, gaster slightly darker (note frontal carinae visible but very faint)
Tetramorium poweri
Tetramorium poweri South Africa
- Frontal carinae visible, basal one-third of first gastral tergite strongly sculptured
180 Side of head with two projecting hairs behind the eye; eye 7 ommatidia long; TL 2.2-2.3 mm; yellowish-brown
{Tetramorium ghindanum}

. {Tetramorium ghindanum} Tetramorium ghindanum Ethiopia
180 Side of head with no projecting hairs behind the eye; eye 9 ommatidia long; TL 2.0-2.1 mm; mid- to dark brown
Tetramorium nefassitense
Tetramorium nefassitense Ethiopia
- Frontal carinae visible, basal one-third of first gastral tergite wholly smooth
- Yellow to yellowish-brown
175 &183 Head with distinct but fine longitudinal rugulae, spaces between smooth; dorsal alitrunk with fine punctulate or or shagreened ground sculpture overlaid by some fine longitudinal rugulae; TL 2.1-2.4 mm; some may be darker to brown
Tetramorium mossanedense
Tetramorium mossamedense southern Africa
183 Head with weak longitudinal rugulae, spaces between finely punctate or granular; TL 2.1-2.4 mm; gaster usually darker
Tetramorium caldarium Sahel savannah origin
tramp species
. {Tetramorium caldarium Congo} Narrow headed Congo Basin & tramp form. Gaster uniformly dark .
. {Tetramorium caldarium} Broad-headed East African & Saudi Arabia form. Gaster with variable lighter areas .
- Rich dark brown to blackish-brown
184 Mandibles smooth & shining; erect hairs short and blunt; petiole and postpetiole almost smooth; TL 2.1-2.3 mm
Tetramorium pusillum
Tetramorium pusillum South Africa
185 Mandibles longitudinally striate; longer scapes (SI 84-91); propodeum with short triangular teeth; TL 2.6-2.7 mm
Tetramorium altivagans
Tetramorium altivagans Kenya & southern Sudan
185 Mandibles delicately striate; shorter scapes (SI 77); propodeum without teeth merely angled; smaller TL 1.9 mm
Tetramorium nigrum
Tetramorium nigrum Tanzania. Kenya & South Sudan
Hairs on dorsal alitrunk and/or first gastral tergite fine and acute apically or absent
caespitum-group Mandibles striate
164 probable exotic, TL 2.6-2.7 mm (illustration is Tetramorium caespitum)
{Tetramorium caespitum}
Tetramorium nautarum Annobon I.
(probable introduction)
convexum-group Mandibles smooth
40 Only minute appressed hairs; TL 2.2-2.3 mm; uniform dull yellow
{Tetramorium wadje}
. .
. {Tetramorium wadje} Tetramorium wadje Ghana & Nigeria
158 With numerous fine hairs and no propodeal armament; TL 1.9-2.0 mm; head dark brown, remainder dull yellow
Tetramorium convexum

Tetramorium convexum Ghana
return to start of key stage
2007, 2008, 2010, 2011, 2013 - Brian Taylor CBiol FSB FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.