Monomorium ophthalmicum

Known only from the damaged holotype.

Identification
Bolton (1987) - This Ethiopian species appears to belong to the M. subopacum complex in the M. salomonis species group. In the key it runs out close to the southern African species Monomorium kitectum and Monomorium willowmorense but has different critical dimensions, as follows.

willowmorense HW: 0.50-0.60 SI: 88-93 eye: 0.24-0.26 x HW

ophthalmicum HW: 0.49 SI: 92 eye: 0.35 x HW

kitectum HW: 0.43-0.45 SI: 100-102 eye: 0.29-0.31 x HW

Apart from this willowmorense workers have 2-3 pairs of hairs on the first gastral tergite in front of the apical transverse row, whereas kitectum and ophthalmicum have only a single pair; and ophthalmicum shows 10 ommatidia in the longest ocular row, a count only equalled by the largest workers of willowmorense.

Distribution based on Regional Taxon Lists
Afrotropical Region: Ethiopia.

Nomenclature

 *  ophthalmicum. Monomorium ophthalmicum Forel, 1894b: 87 (w.) ETHIOPIA. See also: Bolton, 1987: 353.

Worker
Bolton (1987) - TL 2.3, HL 0.62, HW 0.49, CI 79, SL 0.45, SI 92, PW 0.30, AL 0.68 (measurements of head approximate as holotype worker head is crushed).

Anterior clypeal margin with its prominent median section extremely shallowly concave centrally. Dorsum of head crushed but sides apparently evenly shallowly convex and converging behind the eyes. Eyes large, the maximum diameter 0·35 x HW and with 10 ommatidia in the longest row. Promesonotum in profile shallowly convex, the highest point approximately at the midlength. Extreme posterior portion of mesonotal outline sharply downcurved to the metanotal groove but the latter not impressed. Propodeal dorsum extremely feebly concave, almost flat in outline. In dorsal view the posterior half of the propodeal dorsum very shallowly transversely concave. Petiole node in profile narrowly but bluntly subconical. Dorsum of head with very faint reticular patterning only, which becomes more distinct towards the occipital margin. Pronotal dorsum and sides finely reticulate-shagreenate, the mesonotal dorsum similarly but more strongly sculptured. Propodeal dorsum and sides of alitrunk behind the pronotum densely finely reticulate to reticulate-punctate. First gastral tergite very finely shagreenate at extreme base, this fading out posteriorly to fine superficial reticular patterning. Dorsum of head without standing hairs behind the level of the frontal lobes. Dorsal alitrunk without standing hairs. Petiole and postpetiole each with a single pair of backward directed hairs. First gastral tergite with a single pair of elongate hairs, situated approximately at the midlength. Colour uniform medium brown, the legs and antennae dull yellow.

Type Material
Bolton (1987) - Holotype worker, Ethiopia: 'Siidabessinien' (Ilg) [examined].

References based on Global Ant Biodiversity Informatics

 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004