Key to Afrotropical Strumigenys (as Pyramica)

This worker key is based on: Bolton, B. 2000. The ant tribe Dacetini. Memoirs of the American Entomological Institute. 65:1-1028.

Bolton noted: The socially parasitic P. inquilina (Strumigenys inquilina), known only from queens found in a nest of P. lujae, (Strumigenys lujae) is omitted from the key; comparative notes on the queens are given under inquilina.

This key is from a revision study that included the now synonymized genus Pyramica. Therefore there are two keys that treat two sets of Strumigenys species, the key found below (the group of species once classified as Pyramica) and a key to Afrotropical Strumigenys.

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1

 * Antenna with 4 segments; the first funicular segment followed directly by the 2-segmented club . . . . . 2


 * Antenna with 6 segments; the first funicular segment separated from the 2-segmented club by two much smaller segments . . . . . 9

2
return to couplet #1
 * Mandibles linear, elongate and narrow, without preapical teeth; MI > 25. At full closure mandibles engage only at their extreme apices and enclose a large open space between the blades; labral lobes visible between mandibles even at full closure. Cephalic dorsum with small orbicular hairs present; CI 1 00 - 107. (Ghana, Cameroun, Uganda) . . . . . Strumigenys minima


 * Mandibles short and triangular, with preapical teeth; MI 6-17. At full closure mandibles engage throughout their visible length, without a space between the blades; labral lobes not visible when mandibles fully closed . Cephalic dorsum without orbicular hairs; CI 51-88 . . . . . 3

3
return to couplet #2
 * Anterior clypeal margin convex in full-face view. Pronotal humerus with a long flagellate or stiffly projecting specialised hair. Hairs on leading edge of scape fine to narrowly spatulate, all curved toward scape apex . Basal lamella of mandible a low lobe and principal dental row with 7 teeth . . . . . 4


 * Anterior clypeal margin concave in full-face view. Pronotal humerus without a specialised projecting hair of any form . Hairs on leading edge of scape broadly spatulate to spoon-shaped, one or more distinctly curved toward the scape base. Basal lamella of mandible a long narrow triangle that may be truncated apically and principal dental row with 5 teeth . . . . . 6

4
return to couplet #3
 * Clypeus broad, its lateral margins approximately parallel. With head in full-face view the outer margins of the fully closed mandibles intersect the anterior clypeal margin mesad of the anterolateral clypeal angles, so that there is a section of the anterior clypeal margin that projects laterally beyond the outline of the mandible. Dorsum of clypeus without hairs. (Ivory Coast, Ghana, Kenya, Tanzania, Zimbabwe, South Africa) . . . . . Strumigenys marginata


 * Clypeus narrow, its lateral margins more or less evenly convergent anteriorly. With the head in full-face view the outer margins of the fully closed mandibles intersect the anterior clypeal margin at the anterolateral clypeal angles, so that there is no section of the anterior clypeal margin that projects laterally beyond the outline of the mandible. Dorsum of clypeus with abundant short curved hairs . . . . . 5

5
return to couplet #4
 * Pronotum sharply marginate dorsolaterally, the dorsum un sculptured. Hairs on clypeal dorsum spatulate. Metanotal groove indistinct to absent. Ventral lobe of postpetiole spongiform . Small species with short scape and broad head, HL 0.42-0.46, SI 61-67, CI 65-70. (Ivory Coast, Ghana, Cameroun , Gabon , Zaire, Uganda) . . . . . Strumigenys tacta


 * Pronotum not marginate dorsolaterally, the dorsum weakly sculptured. Hairs on clypeal dorsum simple. Metanotal groove broad and deeply impressed. Ventral lobe of postpetiole laminate. Larger species with very long scape and narrow head, HL 0.74, SI 116, CI 51. (Cameroun) . . . . . Strumigenys vodensa

6
return to couplet #3 . . . . . Strumigenys tigrilla
 * Entire body coloured with broad alternating yellow and black transverse bands. Basigastral costulae form a continuous row across the tergite, without a central noncostulate area. Ventral spongiform crest of petiolar peduncle absent between insertion and node. (Ivory Coast, Ghana, Cameroun, Gabon)


 * Body uniformly coloured, without alternating yellow and black broad transverse bands. Basigastral costulae radiate from each side of a non-costulate central area. Ventral spongiform crest of petiolar peduncle complete from insertion to apex of segment . . . . . 7

7
return to couplet #6
 * With head in profile the dorsum with a pair of short erect hairs close to the occipital margin. (Kenya, Tanzania, Angola, South Africa, Madagascar) . . . . . Strumigenys mandibularis


 * With head in profile the dorsum without erect hairs . . . . . 8

8
return to couplet #7
 * Anterior half of clypeus with a broad longitudinal impression mid-dorsally which is filled with short scale-like hairs that are directed toward the midline. Subbasal bend of scape extensively developed, its anterior margin strongly angular. Pronotal dorsum with dense fine longitudinal rugulae or costulae. (Ivory Coast, Ghana) . . . . . Strumigenys fulda


 * Anterior half of clypeus without a longitudinal impression mid-dorsally, this area without short scale-like hairs that are directed toward the midline. Subbasal bend of scape weakly developed, its anterior margin evenly rounded and not angled. Pronotal dorsum smooth or at most with faint superficial shagreening on the glossy surface. (Ivory Coast, Ghana, Nigeria, Chad, Cameroun, Gabon , Zaire, Uganda) . . . . . Strumigenys ninda