Trichomyrmex emeryi

Identification
Bolton (1987):

Worker. TL 2.5-3.4, HL 0.68-0.88, HW 0.62-0.80, CI 89-95, SL 0.52-0.67, SI 78-86, PW 0.36-0.50, AL 0.70-1.00 (20 measured). Mandibles conspicuously longitudinally rugulose to striate-rugulose, the basal tooth reduced to a minute denticle. Eyes relatively small, the maximum diameter 0.16-0.20 x HW and with 6-7 ommatidia in the longest row. Occipital margin in full-face view shallowly concave and somewhat indented medially. Head relatively broad and scapes short (CI and SI above). Promesonotum evenly domed-convex in profile, the metanotal groove shallowly impressed and the propodeal dorsum flat to very feebly convex. Propodeal dorsum on a much lower level than that of promesonotum. Petiole peduncle with an anteroventral low rim or flange. Usually this process runs back approximately to the level of the petiolar spiracle but may be reduced in some workers.

Head without elongate standing hairs dorsally behind the level of the frontal lobes, but quite densely clothed with long decumbent to appressed pubescence which is directed towards the dorsal midline. Similar long pubescence present on all surfaces of dorsal alitrunk but also with much longer conspicuous standing hairs present both on promesonotum and propodeum. Long back-curved hairs numerous on petiole, postpetiole and first gastral tergite and sternite; all these segments also with elongate but relatively sparse pubescence which is decumbent to appressed.

Entire dorsum of head densely longitudinally costulate to rugulose, the sculpture usually quite regular and always with fairly conspicuous punctures visible between the longitudinal components. On sides of head the sculpture tends to fade out or become much less dense below and behind the eyes. Dorsal alitrunk reticulate-punctate, this sculpture overlaid by fine rugular or costulate sculpture which may vary in density and direction on the promesonotum even in members of a single nest-series, but is always transverse on the propodeal dorsum. Sides of alitrunk with rugular or costulate sciilpture usually also present on the pronotum, metapleuron and propodeum. Punctate component sometimes reduced on sides of pronotum so that only faint longitudinal rugulae remain. Rugulae sometimes absent from metapleuron and propodeal sides, leaving the area reticulate-punctate. Petiole and postpetiole generally smooth dorsally but with lateral sculptural vestiges remaining. First gastral tergite unsculptured except for hair-pits. Colour light to dark brown, usually uniform.

This distinctive heavily sculptured species shows very little size variation in any given series and the marked allometric variation characteristic of oscaris does not occur. The form and density of the sculpture immediately isolates emeryi from all other members of the destructor-group.

Distribution based on Regional Taxon Lists
Afrotropical Region: Botswana, Malawi, Mozambique, Zimbabwe.

Nomenclature

 *  emeryi. Monomorium emeryi Mayr, 1895: 132 (w.) MOZAMBIQUE. Combination in Trichomyrmex: Ward et al., 2014: 16. Arnold, 1916: 213 (q.m.). Current subspecies: nominal plus laevior. See also: Bolton, 1987: 325.