Monomorium minor

A specimen from South Africa was collected from a pitfall trap in Acacia mellifera - Rhigozum trichtomum veld.

Identification
Bolton (1987) - A member of the M. australe complex in the M. salomonis species group.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola, Namibia.

Nomenclature

 *  minor. Monomorium salomonis var. minor Stitz, 1923: 156 (w.) NAMIBIA. Raised to species: Bolton, 1987: 350.

Bolton (1987) - As far as can be ascertained no syntypes of this species remain in existence. The original description of minor is short and quite vague, saying merely, '2mm. Smaller than typical form [i.e. salomonis]. Head narrower; antennal scape overreaching occipital margin by its own thickness. Petiole node with peduncle somewhat shorter. Yellow with brownish tint, the gaster in some samples somewhat darkened.'

I have not seen any Namibian specimens matching this description but a series from Porto Alexandre, in south-eastern Angola, fits fairly well and so I have applied the name minor to this series.

Worker
Bolton (1987) - TL 2.6-2.9, HL 0.68-0.70, HW 0.49-0.51, CI 70-74, SL 0.54-0.58, SI 112-116, PW 0.34-0.37, AL 0.78-0.84 (8 measured).

Median portion of clypeus with anterior margin transverse to very shallowly concave, sometimes with a minute notch medially. Maximum diameter of eye 0.28-0.30 x HW, and with 8-9 ommatidia in the longest row. Sides of head weakly convergent behind the eyes and the occipital margin shallowly concave medially in full-face view. Promesonotum shallowly convex in profile, the mesonotum sloping weakly to the very feebly impressed metanotal groove. Propodeal dorsum flattened to weakly impressed, the lateral margins bluntly indicated. Dorsum of head with 2 pairs of standing hairs present behind the level of the frontal lobes; the first pair situated just behind the level of the eyes, the second pair at the occipital margin. Dorsal alitrunk without standing hairs; the petiole with one pair and the postpetiole with two pairs of backward directed hairs. First gastral tergite with hairs evenly distributed over the sclerite in front of the apical transverse row. Cephalic dorsum opaque and with a roughened and silky appearance, the sculpture finely reticulate-shagreenate to punctulate-shagreenate, usually mid-dorsally with superimposed extremely fine scratch-like longitudinal striolae. Dorsal alitrunk finely reticulate-shagreenate on pronotum, grading to feebly punctulate-shagreenate on the propodeum. Colour uniform dull yellow, often with the sides and posterior margin of the first gastral tergite, and the succeeding tergites, slightly darker.

Type Material
Bolton (1987) - Syntype workers, Namibia: Farm Neudamm, 10-15.v.1911 (Michaelsen); Kuibis, 15.vii.1911 (Michaelsen) (not found in, presumed lost).

References based on Global Ant Biodiversity Informatics

 * Bolton B. 1987. A review of the Solenopsis genus-group and revision of Afrotropical Monomorium Mayr (Hymenoptera: Formicidae). Bulletin of the British Museum (Natural History). Entomology 54: 263-452.
 * Stitz H. 1923. Hymenoptera, VII. Formicidae. Beiträge zur Kenntnis der Land- und Süsswasserfauna Deutsch-Südwestafrikas 2: 143-167.