Tetramorium pullulum

A common species that prefers moist forest, e.g., moist evergreen forest, wet forest, and rainforest. Based on the many collections from various kinds of wood (rotten log, dead twig above ground, rotten pocket of tree, live stem), T. pullulum is an opportunistic nester. One colony was found in leaf litter. A majority of the many non-nest collections are from leaf litter. Others were found on vegetation and at a bait.

Identification
Bolton (1980) - A member of the T. bicarinatum species complex in the Tetramorium bicarinatum species group. The shape of the petiole node allies T. pullulum most clearly to Tetramorium amentete and Tetramorium peutli which have the segment similarly constructed. However, in T. amentete the petiole and postpetiole are both coarsely sculptured and the first gastral tergite has sharply defined basal costulae. The colour pattern of T. peutli will quickly separate it from T. pullulum as the former is orange or orange-brown with the gaster much darker, whilst the latter is uniform blackish brown or black. Besides this the petiole dorsum in T. peutli is rugulose whereas it is usually unsculptured in T. pullulum.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola, Cameroun, Central African Republic, Democratic Republic of Congo, Kenya, Sudan, Uganda, Zambia.

Nomenclature

 *  pullulum. Tetramorium guineense st. pullulum Santschi, 1924b: 211, fig. 9 (w.) DEMOCRATIC REPUBLIC OF CONGO. Raised to species and senior synonym of fernandensis, uelensis: Bolton, 1980: 273.
 * uelensis. Xiphomyrmex uelensis Santschi, 1935a: 267 (w.) DEMOCRATIC REPUBLIC OF CONGO. [Unresolved junior primary homonym of uelense Santschi, 1923e: 285, above.] Junior synonym of pullulum: Bolton, 1980: 273.
 * fernandensis. Tetramorium fernandensis Menozzi, 1942: 174, fig. 2 EQUATORIAL GUINEA (Bioko I.). [Also given as new in Eidmann, 1944: 454.] Junior synonym of pullulum: Bolton, 1980: 273.

Worker
Bolton (1980) - TL 3.2-4.0, HL 0.76-0.94, HW 0.63-0.80, CI 81-86, SL 0.52-0.64, SI 79-85, PW 0.46-0.60, AL 0.88-1.12 (10 measured).

Mandibles unsculptured, smooth and shining with scattered minute pits. Anterior clypeal margin with a distinct median notch or impression, the portion of the clypeus immediately posterior to the notch gently transversely concave. Median portion of clypeus with three strong longitudinal carinae, the lateral marginations low and sinuate, usually no more strongly developed than the carinae. Frontal carinae long and strongly developed, reaching back almost to the occipital margin where they merge with the rugoreticular sculpture. Eyes of moderate size, maximum diameter 0.16-0.18, about 0.24-07 x HW. Propodeal spines in profile stout, acute apically, rarely more or less straight, more commonly slightly upcurved along their length or with the extreme apices turned upwards. Metapleural lobes elongatetriangular. With the petiole in profile the posterior face longer than the anterior so that the shallowly convex dorsum is higher behind than in front. Anterior face vertical or nearly so, meeting the convex dorsum in a blunted or indistinctly rounded angle. Dorsum meeting posterior face in a narrowly rounded, prominent angle which projects and overhangs the shallowly concave posterior face. In dorsal view the petiole node usually longer than broad, less commonly about as broad as long. Dorsum of head to the level of the eyes with 5 longitudinal rugae, sometimes these continuing without interruption to the level of the posterior margins of the eyes but often with weaker longitudinal rugulae or cross-meshes appearing in this area. Occipitally the head with a weak reticulum or series of anastomoses, but without the strong rugoreticulum predominant in the group. Dorsal alitrunk with a transverse crest at the site of the promesonotal junction. Pronotum usually with a series of weak longitudinal rugulae running from the anterior margin to the crest. These are widely spaced and may be feeble in some specimens. Mesonotum behind the crest with similar sculpture to pronotum or with the sculpture variously reduced until the surface is almost smooth. Propodeal dorsum usually (but not always) retaining traces of fine rugosity. Petiole and postpetiole unsculptured dorsally or the former with faint rugular vestiges. Basigastral costulae as such absent from the first tergite but at least the basal third and sometimes the whole of the sclerite with dense fine punctulation, many of the constituents of which are roughly aligned and reproduce a costulate effect. All dorsal surfaces of head and body with numerous strong hairs. Colour uniform blackish brown or black.

Type Material
Bolton (1980) - Holotype worker, ZAIRE: Haut Uelé, Moto, 1920 (L. Burgeon) [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.
 * Eidmann H. 1944. Die Ameisenfauna von Fernando Poo. 27. Beitrag zu den Ergebnissen der Westafrika-Expedition. Zool. Jahrb. Abt. Syst. Ökol. Geogr. Tiere 76: 413-490.
 * Menozzi C. 1942. Formiche dell'isola Fernando Poo e del territorio del Rio Muni (Guinea Spagnola). 24. Beitrag zu den wissenschaftlichen Ergebnissen der Forschungsreise H. Eidmann nach Spanisch-Guinea 1939 bis 1940. Zoologischer Anzeiger 140: 164-182.
 * Ross S. R. P. J., F. Hita Garcia, G. Fischer, and M. K. Peters. 2018. Selective logging intensity in an East African rain forest predicts reductions in ant diversity. Biotropica 1-11.