Monomorium taedium

Collected from grasslands, semi-open habitats, to closed woodland Acacia habitat via hand collecting, pitfall trapping and in leaf-litter sampling.

Identification
Heterick (2006) - A member of the M. exiguum complex in the M. monomorium species group.

Bolton (1987) - Among the Afrotropical species with only 11 antennal segments taedium is isolated by its relatively large eyes, dark colour, size, and lack of an enlarged and characteristically shaped postpetiole such as is seen in Monomorium bequaerti and its allies. Like Monomorium mictilis and Monomorium fastidium, taedium also lacks a pair of standing hairs on the anterior margin of the pronotum between the humeral pair, but taedium is larger than either of these and has many more ommatidia in the eye.

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

Nomenclature

 *  taedium. Monomorium taedium Bolton, 1987: 415 (w.) SOUTH AFRICA.

Worker
Holotype. TL 1.7, HL 0.46, HW 0.38, CI 83, SL 0.31, SI 82, PW 0.25, AL 0.49.

Clypeal carinae conspicuous, close together posteriorly and widely divergent anteriorly. Anterior margin of prominent median portion of clypeus transverse to exceptionally feebly convex, the anterior margin meeting the sides in an obtuse angle but lacking projecting sharp angles or denticles. Maximum diameter of eye 0.21 x HW, with 6 ommatidia in the longest row. With the head in profile the eye almost as high as long and the outer ring of ommatidia enclosing three longitudinal rows, unlike most other members of the shilohense-complex where the outer ring of ommatidia only encloses a single longitudinal row of 2-4 ommatidia. In full-face view the eyes conspicuously in front of the midlength of the sides of the head. Antennae with 11 segments. Antennal scapes, when laid straight back from their insertions, failing to reach the occipital margin Promesonotum in profile feebly convex and forming a long shallow slope back to the broadly impressed metanotal groove ; the latter with conspicuous cross-ribs. Propodeal dorsum highest immediately behind the metanotal groove, sloping downwards posteriorly and rounding broadly and evenly into the declivity. Propodeal spiracle small. Petiole with a short narrow anterior peduncle which has a very small anteroventral process. Ventral outline of petiole markedly concave from process to level of the spiracle, behind which it is markedly convex beneath the node proper. Petiole node in profile bluntly subconical and rounded above, the postpetiole slightly smaller but much more broadly rounded dorsally. All dorsal surfaces of head and body with standing hairs, the promesonotum with 3-4 pairs but the pronotum lacking a pair on the anterior margin between the humeral pair. Sculpture absent except for metanotal cross-ribs and some faint punctulate areas on the mesopleuron. Colour glossy medium brown.

Paratypes. TL 1.6-1.7, HL 0.42-0.47, HW 0.34-0.38, CI 80-83, SL 0.28-0.31, SI 80-83, PW 0.23-0.26, AL 0.44-0.49 (7 measured). As holotype but some lighter brown in colour. Maximum diameter of eye 0.19-0.22 x HW, the outer ring of ommatidia enclosing three longitudinal rows as in the holotype, or enclosing two rows plus one or two other ommatidia; with 5-6 ommatidia in the longest row.

Type Material
Holotype worker, South Africa: Natal, Umlalazi Nat. Res., 25.iii.1979 (D. J. Brothers). Paratypes. 7 workers with same data as holotype (BMNH; ).

References based on Global Ant Biodiversity Informatics

 * Samways M. J., R. Osborn, and F. Carliel. 1997. Effect of a highway on ant (Hymenoptera: Formicidae) species composition and abundance, with a recommendation for roadside verge width. Biodiversity and Conservation 6: 903-913.