Monomorium macrops

Nothing is known about the biology of .

Identification
Bolton (1987) - A member of the M. setuliferum species group. Arnold originally described this form as a subspecies of Monomorium mediocre, but in fact macrops is a very distinctive species, not closely related to mediocre which has smaller eyes (0.21-0.24 x HW) situated at the midlength of the sides, lacks standing hairs on the head, alitrunk and first gastral tergite (except for the apical transverse row), and retains cephalic sculpture. In fact macrops, known only from the South African type-series, is something of an enigma.

As the setuliferum-group is presently defined macrops should be included, but it has a number of features which strongly indicate that it has acquired these characters independently of any other member of the group. For instance, the sculpture and pilosity of macrops appear to represent a reduction of that seen in the mediocre-complex and elsewhere in the salomonis-group. The head remains relatively long and narrow (CI 78-80), approached only by Monomorium alamarum (CI 79-83) and outside the combined range shown by the remaining species of the group (CI 83-92). The eyes of macrops, though large and shifted forward, are not as oblique as in most species, and the petiole has a relatively large anteroventral process. In summary the origins of macrops remain shrouded in mystery. Though indubitably it is derived from somewhere in the salomonis-group, it must have arisen from a part of the group different from any other species placed in the setuliferum-group as it is presently constructed.

Distribution based on Regional Taxon Lists
Afrotropical Region: South Africa.

Nomenclature

 *  macrops. Monomorium mediocre subsp. macrops Arnold, 1944: 11, fig. 17 (w.) SOUTH AFRICA. Raised to species: Bolton, 1987: 369.

Worker
Bolton (1987) - TL 2.0-2.1, HL 0.54-0.56, HW 0.42-0.45, CI 78-80, SL 0.38, SI 84-90, PW 0.27-0.28, AL 0.54 (3 measured).

Eyes relatively large, maximum diameter 0.31-0.33 x HW, with 8-9 ommatidia in the longest row. Outline shape of body as Fig. 59; the metanotal groove weakly impressed and the petiole with a fairly large and conspicuous anteroventral process. Standing pilosity present on head and body but sparse. On the cephalic dorsum three pairs of hairs are present which straddle the midline behind the level of the frontal lobes. The first pair is situated at about the level of the mid length of the eye, the second behind the level of the eye, and the third at the occipital margin. On the occipital margin is another pair of hairs, situated close to the corners. Pronotum with a pair of standing hairs at the humeri, mesonotum with or without a short pair anteriorly, propodeum hairless. Petiole with one pair and postpetiole with two pairs of backward directed hairs. First gastral tergite with several pairs of hairs on the basal half, the apical half apparently hairless except for the marginal transverse row. Dorsum of head unsculptured except for hair-pits and faint superficial reticular patterning at the occipital border and immediately behind the frontal lobes. Promesonotum weakly reticulate dorsally, the propodeum weakly reticulate-punctulate. First gastral tergite smooth, with vestigial superficial reticular patterning basally. Colour light to medium brown, the gaster slightly darker than the head and alitrunk.

Type Material
Bolton (1987) - Syntype workers, South Africa: Cape Prov., Victoria West (R. Smithers) [examined].

References based on Global Ant Biodiversity Informatics

 * Arnold G. 1944. New species of African Hymenoptera. No. 5. Occasional Papers of the National Museum of Southern Rhodesia. 2: 1-38.
 * Botes, A., M.A. McGeoch, H.G. Robertson, A. van Niekerk, H.P. Davids and S.L. Chown. 2006. Ants, altitude and change in the northern Cape Floristic Region. Journal of Biogeography 33:71-90
 * Ettershank G. 1966. A generic revision of the world Myrmicinae related to Solenopsis and Pheidologeton (Hymenoptera: Formicidae). Aust. J. Zool. 14: 73-171.