Tetramorium typhlops

Identification
One of the two minute species (HW < 0.50, SL < 0.35) known in this group, T. typhlops and Tetramorium warreni are isolated from all other species by their very small size, single-faceted eyes, complete lack of frontal carinae and antennal scrobes and vestigial or absent sculpture. These two species are best separated by the condition of the lateral portions of the clypeus which form a raised shield or wall in front of the antennal insertions. In T. warreni this raised wall is strongly developed, distinctly convex above and relatively high. If the head is viewed from behind and slightly above then the clypeal shields can be seen rising in front of the antennal insertions to a height greater than that of the frontal lobes which are immediately dorsal to the insertions. In T. typhlops on the other hand the lateral portions of the clypeus are not nearly so strikingly developed and are not obviously convex above. If the head is viewed from behind and slightly above then the lateral portion of the clypeus slopes away in a more or less straight line towards the side of the head from a point noticeably below the level of the frontal lobes which are immediately dorsal to the antennal insertions. Other characters useful in separating the two species are the presence of a minute median indentation in the clypeal margin of T. warreni, absent in T. typhlops, and the fact that the petiole node in dorsal view is distinctly broader than long in T. warreni, about as broad as long in T. typhlops.

Distribution based on Regional Taxon Lists
Afrotropical Region: Ivory Coast.

Nomenclature

 *  typhlops. Tetramorium typhlops Bolton, 1980: 293, fig. 70 (w.) IVORY COAST.

Worker
Holotype. TL 2.1, HL 0.50, HW 0.42, CI 84, SL 0.30, SI 71, PW 0.30, AL 0.56. Paratypes (2 measured): TL 2.0-2.1, HL 0.48-0.50, HW 0.41-0.42, CI 84-85, SL 0.29-0.30, SI 70-71, PW 0.28-0.30, AL 0.54-0.56.

Mandibles longitudinally striate. Anterior clypeal margin entire, without a median notch or impression. Median carina weakly developed but running the length of the clypeus. Frontal carinae absent, the ends of the weak frontal lobes forming a feeble margin for the posterior portion of the antennal fossa. Antennal scrobes absent, the dorsum of the head rounding into the sides without interruption. Eyes of a single very poorly defined facet, represented only by a discoloured patch on the sides of the head. Diameter of the eye 0.02, about 0.05 x HW. Minute species with HW < 0.45, the antennal scapes both absolutely and relatively short, SL < 0.35, SI < 75. Alitrunk in profile not interrupted at the metanotal groove. Propodeum armed with a pair of short spines which are about as long as the bluntly triangular metapleural lobes. Petiole in profile with a short, thick anterior peduncle and a low node. Anterodorsal angle of petiole a blunt rightangle, the posterodorsal angle not defined, the dorsum rounding into the posterior face. Node of petiole in dorsal view about as long as broad, very slightly broader behind than in front. Dorsum of head with minute and faint irregular longitudinal rugulae and a vestigial ground-sculpture which amounts to no more than a faint roughening of the surface. Dorsal alitrunk unsculptured except for minute punctulae. Petiole, postpetiole and gaster unsculptured. All dorsal surfaces of head and body with short, fine hairs. Dorsal (outer) surfaces of hind tibiae with short pubescence which is mostly subdecumbent. Colour uniform clear pale yellow.

Paratypes: As holotype.

Type Material
Holotype worker, Ivory Coast: Lamto (Toumodi), AA80 nid 10, 9.xii.1963 (J. Lévieux). Paratypes. 1 worker with same data as holotype but lacking date; 1 worker with same data but coded AA8J and lacking date (BMNH; ).

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.
 * Yeo K., T. Delsinne, S. Komate, L. L. Alonso, D. Aidara, and C. Peeters. 2016. Diversity and distribution of ant assemblages above and below ground in a West African forest–savannah mosaic (Lamto, Cote d’Ivoire). Insectes Sociaux DOI 10.1007/s00040-016-0527-6