Technomyrmex senex

This widely distributed species inhabits the leaf litter layer but also ascends low vegetation.

Identification
Bolton (2007) - A member of the Technomyrmex textor group. Its closest relatives are Technomyrmex parviflavus and Technomyrmex sycorax but both these species lack setae on the third gastral tergite and have the head and mesosoma yellow.

Very badly abraded specimens of Technomyrmex moerens that have lost almost all their setae may be confused with senex as the two are similarly coloured and both produce samples with pale coxae. Such abraded samples of moerens can be distinguished because the cephalic sculpture is uniformly fine and not reticulate-punctulate, the dorsal length of the propodeum in profile is distinctly less than the depth of the declivity to the spiracle, the sea pes are shorter (S[ 102 - 119) and the eyes are located more anteriorly on the head (EPI 54 - 65).

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Central African Republic, Democratic Republic of Congo, Gabon, Ghana.

Nomenclature

 *  senex. Technomyrmex senex Bolton, 2007a: 36, fig. 17 (w.) GABON.

Worker
Holotype. TL 2.7, HL 0.61, HW 0.52, SL 0.66, PW 0.38, WL 0.88. Indices: CI 85, SI 127, OI 27, EPI 80, DTI 147.

Dorsum of head behind clypeus entirely lacks setae. Anterior clypeal margin with a shallow median impression that is broader than long; less than semicircular. Posterior margin of head in full-face view weakly indented medially. Eyes of moderate size and located just in front of the midlength; in full-face view the outer margins of the eyes just fail to reach the outline of the sides. Median portion of c1ypeus and entire dorsum of head with fine, very dense reticulate-punctulate sculpture. Dorsal surfaces of mesosoma and declivity of propodeum entirely lack setae. In profile the mesonotal dorsal outline with a horizontally flat, or nearly flat, anterior section and a much shorter, much more steeply sloped declivitous surface posteriorly, the two separated by a distinct angle or step in the outline. Propodeal dorsum more or less flat in profile and meeting the straight declivity in an angle; straight-line length of dorsum slightly greater than depth of declivity to the spiracle. Dorsal surfaces of pronotum, mesonotum and propodeum finely reticulate-punctulate. Gastral tergites 1 - 2 without setae, gastral tergites 3 – 4 each with 2 3 pairs present that are longer than the maximum diameter of the eye. (In the holotype gastral tergite 4 is partially retracted below tergite 3, probably due to the specimen drying from alcohol, so the setae on 4 have been flattened down.) First gastral tergite finely shagreenate, less strongly sculptured than the dorsal mesosoma. Colour dark brown throughout except for the trochanters and the middle and hind coxae, which are yellow (see notes below). Middle and hind tarsi lighter than the tibiae and femora.

Non-paratypic workers. TL 2.5 - 2.8, HL 0.58 - 0.64, HW 0.48 - 0.54, SL 0.60 - 0.66, PW 0.34 - 0.39, WL 0.82 0.90 (15 measured). Indices: CI 82 - 88, SI 122 - 129, OI 26 - 30, EPI 70 - 80, DTI 140 - 158. Head and body colour varies from dark brown to black. The middle and hind coxae are usually the same colour as the mesosoma and femora, but sometimes, as in the holotype, they are yellow. Intermediate shades exist and coxal colour does not seem to be associated with any other character. All variants occur in all known populations and therefore the feature -is not accorded any taxonomic significance at species-rank here. In some specimens the reticulate-punctulate sculpture of the head is weaker and not as sharply developed as in the holotype.

Type Material
Holotype worker, Gabon: Makokou, x.1972 (I. Lieberburg).

References based on Global Ant Biodiversity Informatics

 * Bolton B. 2007. Taxonomy of the dolichoderine ant genus Technomyrmex Mayr (Hymenoptera: Formicidae) based on the worker caste. Contributions of the American Entomological Institute 35(1): 1-150.
 * Bolton, B. "Taxonomy of the dolichoderine ant genus Technomyrmex Mayr (Hymenoptera: Formicidae) based on the worker caste." Contributions of the American Entomological Institute 35, no. 1 (2007): 1-149.
 * Diame L., B. Taylor, R. Blatrix, J. F. Vayssieres, J. Y. Rey, I. Grechi, and K. Diarra. 2017. A preliminary checklist of the ant (Hymenoptera, Formicidae) fauna of Senegal. Journal of Insect Biodiversity 5(15): 1-16.