Tetramorium navum

Specimens have been found in rainforest and dry evergreen forest.

Identification
Bolton (1977) - Among the species of the ornatum-group in which the propodeal spines are downcurved, navum is distinguished by having strongly developed frontal carinae and sparse but strong carinate sculpture on the head. In other species showing very strong longitudinal cephalic sculpture the components are much more densely packed, with 10 or more between the frontal carinae at the level of the eyes, or the spaces between the longitudinal components are packed with coarse reticulate-punctate ground sculpture.

Distribution based on Regional Taxon Lists
Indo-Australian Region: New Guinea.

Nomenclature

 *  navum. Tetramorium navum Bolton, 1977: 106, fig. 27 (w.) NEW GUINEA.

Worker
Holotype. TL 3.3, HL 0.78, HW 0.74, CI 95, SL 0.58, SI 78, PW 0.52, AL 0.92.

Mandibles striate. Anterior clypeal margin extremely feebly concave (straight to feebly convex in paratype series). Frontal carinae long and strong, extending back almost to the occipital corners. Maximum diameter of eye c. 0.16. Occipital margin of head broadly and shallowly concave in full-face view, sides of head behind eyes feebly convex. Propodeal spines stout, long and acute, somewhat elevated but slightly downcurved along their length. Metapleural lobes elongate-triangular and acute. Petiole node in profile with a downcurved anterior peduncle. Dorsal surface of petiole node curving evenly into posterior face, the two not separated by an angle. Dorsal length of node in profile about equal to the height of the tergal portion of the node. Postpetiole in profile evenly convex, dome-like. Median portion of clypeus with five longitudinal carinae, the outermost very close to the concave edge of the clypeus just in front of the frontal carinal lobe. (In a few paratypes only the median and outer carinae are strongly developed, the inner pair being feeble.) Dorsum of head sculptured with strong, widely spaced longitudinal carinae, about seven in number between the frontal carinae at the level of the eyes. A few very weak cross-meshes present, much weaker than the carinae, and the ground sculpture between the carinae exceedingly feeble. Dorsal alitrunk with a loose rugoreticulum. Petiole sparsely and weakly rugulose, the dorsal postpetiole and gaster unsculptured but the sides of the postpetiole retaining vestigial sculpture basally. Fine erect or suberect hairs present upon all dorsal surfaces of head and body but hairs on scapes and dorsal (outer) surfaces of hind tibiae very short, decumbent or appressed. Colour very dark brown, the appendages lighter.

Paratypes. TL 3.0-3.5, HL 0.74-0.84, HW 0.70-0.80, CI 92-95, SL 0.56-0.64, SI 76-81, PW 0.48-0.56, AL 0.84-0.98. Maximum diameter of eye 0.15-0.18 (10 measured). As holotype, with the variation noted above and also some paratypes with propodeal spines feebly sinuate (Fig. 27) as the downcurvature tends to flatten out or even be very slightly upcurved towards the apices.

Type Material
Holotype worker, New Guinea: Nadzab, 20-22.v.1955, no. 1101, dry evgr. for. (E. O. Wilson). Paratypes. 2 workers with same data as holotype; 2 workers with same data but no. 1086; 6 workers with same data but no. 1093 (MCZC; ).

References based on Global Ant Biodiversity Informatics

 * Bolton B. 1977. The ant tribe Tetramoriini (Hymenoptera: Formicidae). The genus Tetramorium Mayr in the Oriental and Indo-Australian regions, and in Australia. Bulletin of the British Museum (Natural History). Entomology 36:67-151.
 * Bolton, B. "The ant tribe Tetramoriini (Hymenoptera: Formicinae. The genus Tetramorium Mayr in the Oriental and Indo-Australian regions and in Australia." Bulletin of the British Museum (National History): Entomology series 36, no. 2 (1977): 68-151.
 * Janda M., G. D. Alpert, M. L. Borowiec, E. P. Economo, P. Klimes, E. Sarnat, and S. O. Shattuck. 2011. Cheklist of ants described and recorded from New Guinea and associated islands. Available on http://www.newguineants.org/. Accessed on 24th Feb. 2011.