Key to Afrotropical Tetramorium species groups

This key is based on Bolton 1980 adding the decem group following Hita & Fisher (2014)

0

 * Antennae with 10 segments => decem group (Key to species)


 * Antennae with 11 or 12 segments .....1

1
return to couplet .....0


 * Antennae with 11 segments .....2


 * Antennae with 12 segments .....4

2
return to couplet .....1


 * Petiole squamiform or represented in profile by a high, narrow node ….. weitzeckeri group (Key to species)


 * Petiole strongly nodiform .....3

3
return to couplet .....2


 * Dorsal (outer) surface of hind tibiae only with fine pubescence. Hairs on first gastral tergite directed towards midline, at least in part …. angulinode group
 * Dorsal (outer) surface of hind tibiae only with long projecting hairs. Hairs on first gastral tergite not directed towards midline….. tortuosum group (Key to species)

4
return to couplet .....1


 * SI 100 or more .....5


 * SI < 100 .....9

5
return to couplet .....4


 * Frontal carinae extending back well beyond the level of the posterior margins of the eye .....6
 * Frontal carinae ending at or in front the level of the eyes .....7

6
return to couplet .....5


 * Maximum diameter of eye 0,25 x HW at minimum, usually greater. Longest row of facets with at least 9 ommatidia. Petiole node high and quite narrow in profile …..setigerum group (in part)


 * Maximum diameter of eye 0,24 x HW at maximum, usually smaller. Longest row of facets with 7-8 ommatidia. Petiole node long and low in profile …..flabellum group (in part)

7
return to couplet .....5


 * Petiole node in profile long and low, in dorsal view usually longer than broad.....8
 * Petiole node in profile high and narrow, in dorsal view distinctly broader than long …..aculeatum group

8
return to couplet .....7


 * Lateral portions of clypeus prominent as a tooth or crest on each side in full face view. When viewed from above and behind, the lateral parts of the clypeus rise to a high peak in front of the antennal insertions and then slope steeply down towards the median portion of the clypeus …..sericeiventre group


 * Lateral portions of clypeus not strongly modified as above …..setigerum group (part)

9
return to couplet .....4


 * Eyes very small or minute. Maximum diameter < 0,17xHW, less than maximum width of scape. Commonly only 1-5 facets altogether, but always with 5 or less ommatidia in the longest row …..shilohense group


 * Eyes larger. Maximum diameter >0,20xHW, greater than maximum width of scape, with more than 5 facets in the longest row .....10

10
return to couplet .....9
 * Petiole, and sometimes also postpetiole, squamiform…..squaminode group


 * Petiole not squamiform.....11

11
return to couplet .....10
 * Lamellate appendage of sting spatulate or linear…..grassii group


 * Lamellate appendage of sting dentiform, triangular or pennant shaped .....12

12
return to couplet .....11


 * Frontal carinae short, ending in front of the level of the posterior margins of the eyes .....13
 * Frontal carinae long, reaching back well beyond the level of the posterior margins of the eyes, usually approaching or even reaching the occipital margin .....16

13
return to couplet .....12


 * Either anterior clypeal margin with a broad deep indentation medially or ventral surface of head with ammochetae hairs present or both …..solidum group


 * Anterior clypeal margin entire and ventral surface of head without ammochetae hairs .....14

14
return to couplet .....13
 * Hairs on dorsal alitrunk and/or first gastral tergite short, stout, and blunt apically …..simillimum group (part)


 * Hairs on dorsal alitrunk and/or first gastral tergite fine and acute apically, or hairs absent from both these surfaces .....15

15
return to couplet .....14
 * Mandibles striate …..caespitum group


 * Mandibles smooth …..convexum group

16
return to couplet .....12
 * Anterior clypeal margin with a median notch or impression, even if small .....17
 * Anterior clypeal margin entire, without a trace of median notch or impression .....21

17
return to couplet .....16


 * Occipital region of head with a rugoreticulum …..bicarinatum group


 * Occipital region of head at most with a few anastomoses, without a rugoreticulum .....18

18
return to couplet .....17
 * Propodeum with a pair of small triangular teeth or denticles …..dumezi group (part)


 * Propodeum with a pair of spines .....19

19
return to couplet .....19
 * Dorsal surfaces of petiole and postpetiole unsculptured or at most with only vestigial traces of sculpture …..camerunense group (part)


 * Dorsal surfaces of petiole, postpetiole or both distinctly sculptured .....20

20
return to couplet .....18
 * Node of postpetiole in dorsal view longer than broad…..camerunense group (part)


 * Node of postpetiole in dorsal view broader than long…..capense group

21
return to couplet .....16
 * Propodeum armed with a pair of elongate spines .....22
 * Propodeum at most with a pair of short, triangular teeth; sometimes only with a pair of denticles, most rarely unarmed .....25

22
return to couplet .....21
 * Dorsal (outer) surface of hind tibiae with erect or suberect hairs or pubescence .....23
 * Dorsal (outer) surface of hind tibiae without erect or suberect hairs or pubescence .....24

23
return to couplet .....22
 * Occipital region of head with a rugoreticulum …..quadridentatum group (part)


 * Occipital region of head without a rugoreticulum …..camerunense group (part)

24
return to couplet .....22
 * Either the anterior and dorsal faces of the petiole node in profile meeting in a smooth curve without a developed anterodorsal angle, or the eyes large with maximum diameter >0,30 x HW …..quadridentatum group (part)


 * Anterior and dorsal faces of the petiole node in profile meeting in an angle, a defined anterodorsal angle present. Eyes smaller< 0,26 x HW…..flabellum group (part)

25
return to couplet .....21
 * Mandibles longitudinally striate and the anterior and dorsal faces of the petiole node meeting in a smooth continuous convexity, without an anterodorsal angle …..quadridentatum group (part)


 * Mandibles smooth or striate. If the latter, then a distinct anterodorsal angle developed which separates anterior and dorsal faces of the petiole node .....26

26
return to couplet .....25
 * Mandibles usually sculptured. Hairs on dorsal alitrunk short, stout and blunt when present; if absent, then the eyes large, maximum diameter > 0,29 x HW or more …..simillimum group (part)


 * Mandibles usually smooth. Hairs on dorsal alitrunk fine and acute when present; if present, then eyes with maximum diameter < 0,29 x HW …..dumezi group (part)