Tetramorium minusculum

Two recent collections by Gómez and Kouakou were of ground foragers in two disparate habitats, primary forest and a ruderal area.

Identification
A member of the Tetramorium angulinode species group.

Bolton (1980) - When Santschi first described this small species he associated it with T. muralti on the ground that both had very reduced sculpture. However, the nodiform petiole and gastral pilosity indicate that the true affinities of T. minusculum lie with Tetramorium angulinode and its allies. Amongst these species T. minusculum is recognizable by its small size and reduced sculpture.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Ghana, Ivory Coast, Sudan.

Nomenclature

 *  minusculum. Xiphomyrmex minusculus Santschi, 1914d: 369, fig. 32 (w.) CAMEROUN. Combination in Tetramorium: Bolton, 1980: 240. Senior synonym of amen: Bolton, 1980: 240.
 * amen. Xiphomyrmex minusculus subsp. amen Weber, 1943c: 376 (w.) SUDAN. Junior synonym of minusculum: Bolton, 1980: 240.

Worker
Bolton (1980) - TL 2:1-2-3, HL 0:52-0:54, HW 0:48-0:52, CI 92-96, SL 0:34-0:36, SI 68-71, PW 0:36-0:40, AL 0-52-0-60 (5 measured).

Mandibles smooth and shining with scattered minute pits. Anterior clypeal margin with a small median impression. Antennal scrobes strongly developed, broad, bounded above by the frontal carinae, below by a longitudinal ruga running above the eye and divided into upper and lower sections anteriorly by a longitudinal carina which runs back to the level of the posterior margin of the eye. Pronotal corners sharply angular in dorsal view. Propodeal spines short, stout and acute; the metapleural lobes triangular. Petiole nodiform, in profile slightly higher than long, in dorsal view about as long as broad or slightly longer than broad. Postpetiole transverse, distinctly broader than long. Sculpture very reduced, the head with a few feeble longitudinal rugulae on each side of the median carina, these rugulae short or broken and the spaces between them smooth or with only the faintest traces of superficial ground-sculpture. Dorsal alitrunk with only 4-5 widely spaced longitudinal rugulae, the spaces between them shining. Pedicel segments and gaster smooth and shining, unsculptured except for the sides of the petiole where faint traces of sculpture can usually be seen. Fine, simple acute hairs present on all dorsal surfaces of head and body, those on the first tergite directed towards the midline on the apical two-thirds of the sclerite. Colour uniform blackish brown to black.

Type Material
Bolton (1980) - Holotype worker, CAMEROUN: Victoria (F. Silvestri) [examined].

Xiphomyrmex minusculus subsp. amen Weber, 1943: 376. Holotype worker, SUDAN: Imatong Mts, 4.viii.1939, no. 1430 (N. A. Weber) [examined].

References based on Global Ant Biodiversity Informatics

 * Bolton B. 1980. The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Ethiopian zoogeographical region. Bulletin of the British Museum (Natural History). Entomology 40: 193-384.
 * Kouakou L. M. M., K. Yeo, K. Ouattara, W. Dekoninck, T. Delsinne, and S. Konate. 2018. Investigating urban ant community (Hymenoptera: Formicidae) in port cities and in major towns along the border in Côte d’Ivoire: a rapid assessment to detect potential introduced invasive ant species. Journal of Animal and Plant Sciences 36(1): 5793-5811.
 * Kouakou L. M. M., W. Dekoninck, M. Kone, T. Delsinne, K. Yeo, K. Ouattara, and S. Konate. 2018. Diversity and distribution of introduced and potentially invasive ant species from the three main ecoregions of Côte d’Ivoire (West Africa). Belgian Journal of Zoology 148 (1): 83–103.
 * Weber N. A. 1943. The ants of the Imatong Mountains, Anglo-Egyptian Sudan. Bulletin of the Museum of Comparative Zoology 93: 263-389.
 * Yeo K., and A. Hormenyo. 2007. A Rapid Survey of Ants in Ajenjua Bepo and Mamang River Forest Reserves, Eastern Region of Ghana. Pp 27-29. In McCullough, J., P. Hoke, P. Naskrecki, and Y. Osei-Owusu (eds.). 2008. A Rapid Biological Assessment of the Ajenjua Bepo and Mamang River Forest Reserves, Ghana. RAP Bulletin of Biological Assessment 50. Conservation International, Arlington, VA, USA.