Monomorium shilohense

Most specimens have been collected in semi-open habitats such as bushveld and acacia woodland.

Identification
Bolton (1987) - A member of the M. boerorum complex in the M. monomorium species group. One of only six species in the region to combine 12-segmented antennae with the characteristic eye form described above. M. shilohense is separated from the other five by its colour, the shape and size of its eyes, and its pilosity. In Monomorium sryetum the dorsal alitrunk has only a single pair of standing hairs, at the pronotal humeri, whilst all the others have more than one pair. Monomorium trake and Monomorium rotundatum have small eyes (0.17-0.19 x HW as opposed to 0.21-0.25 x HW elsewhere) which appear almost circular in profile, being only fractionally longer than high rather than distinctly elongate and narrow as seen in the remaining four species. In Monomorium inquietum and trake the anterior clypeal margin is evenly convex, lacking the differentiated prominent median portion developed by the other four species. In Monomorium floricola and inquietum the head is conspicuously brown in colour, whereas it is yellow in the remaining four species.

Distribution based on Regional Taxon Lists
Afrotropical Region: Zimbabwe.

Nomenclature

 *  shilohense. Monomorium braunsi var. shilohensis Forel, 1913j: 217 (w.) ZIMBABWE. Raised to species: Bolton, 1987: 410.

Worker
Bolton (1987) - TL 1.5-1.6, HL 0.38-0.44, HW 0.30-0.34, CI 77-81, SL 0.24-0.28, SI 80-85, PW 0.19-0.23, AL 0.42-0.46 (5 measured).

Anterior clypeal margin transverse to feebly concave between the apices of the weakly developed clypeal carinae, the latter distinctly divergent anteriorly but not terminating in teeth or projecting angles. Instead the anterior margin and lateral margins of the projecting median section of the clypeus meet in obtuse angles. Maximum diameter of eye 0.23-0.24 x HW. In profile the eye conspicuously longer than high, the ommatidia arranged as an outer ring which encircles a single inner longitudinal row. The encircled row consists usually of 3 ommatidia but rarely 4 may be present. In full-face view the eyes distinctly in front of the midlength of the sides and the scapes, when laid straight back from their insertions, fail to reach the occipital margin. Promesonotum shallowly convex, almost flat posteriorly, sloping to the metanotal groove which is shallow and almost unimpressed. Propodeal dorsum continues the slope of the posterior mesonotum and the propodeal spiracle is minute and pinhole-like. Peduncle of petiole short and subtended by a short but deep and conspicuous process. Petiole node low and broadly subconical, its ventral surface distinctly bulging and convex; the subpetiolar process is confluent with this bulge. Postpetiole low and rounded, smaller than the petiole. All available specimens are abraded but the promesonotum apparently has 3-4 pairs of standing hairs and the propodeum one pair. The head, petiole, postpetiole and gaster also have standing hairs present. Head and body without sculpture except for metanotal cross-ribs and some weak granular sculpture on the mesopleuron. Colour yellow throughout, the apical half of the first gastral tergite without a transverse brown band.

Type Material
Bolton (1987) - Syntype workers, Zimbabwe: Shiloh, 10.v.1913, no. 173 (G. Arnold) [examined].