Monomorium rastractum

This species is know to inhabit semi-open areas such as Bushveld and scrub habitats.

Identification
Bolton (1987) - A member of the M. leopoldinum complex in the M. monomorium species group. A very distinctive species with relatively large eyes, rastractum combines the clypeal structure of the altinode-complex with the petiole form of the leopoldinum-complex and appears to represent an intermediate between these two informal groups. The outline shape of the alitrunk in rastractum is very similar to that of Monomorium fugelanum, but the petiole is lower, much smaller and more obviously conical. The postpetiole lacks the high vertical anterior face shown by fugelanum and its allies in the altinode-complex. Within the leopoldinum-complex rastractum is closest related to Monomorium borlei and Monomorium springvalense, but the former has a large propodeal spiracle and only 3 pairs of standing hairs on the promesonotum. The latter also has only 3-4 pairs of standing hairs on the promesonotum, and has a broader head and relatively smaller eyes than rastractum, 0.21-0.23 x HW as opposed to 0.27 x HW.

Distribution based on Regional Taxon Lists
Afrotropical Region: Kenya.

Nomenclature

 *  rastractum. Monomorium rastractum Bolton, 1987: 406 (w.) KENYA.

Worker
Holotype. TL 1.9, HL 0.50, HW 0.37, CI 74, SL 0.34, SI 92, PW 0.24, AL 0.50.

Clypeal carinae widely separated; strongly divergent anteriorly, terminating at the anterior margin in a pair of low, relatively broad projecting angles. Prominent median portion of clypeus with its anterior margin extremely feebly concave between the projecting angles, the latter separating its anterior and lateral margins. Eyes relatively large, 0.27 x HW and with 7 ommatidia in the longest row. In full-face view the large eyes conspicuously in front of the midlength of the sides. Antennal scapes, when laid straight back from their insertions, distinctly failing to reach the occipital margin. Sides of head shallowly convex behind the eyes and somewhat convergent posteriorly. Occipital margin shallowly concave medially. Promesonotal dorsum in profile shallowly convex, highest at about the midlength of the pronotum, the posterior half of the pronotum and the entire mesonotum forming a gradual slope to the metanotal groove; the latter only weakly and quite narrowly impressed. Metanotal cross-ribs short but conspicuous. Propodeal spiracle minute and pinhole-like. Propodeal dorsal outline forming a single even long convexity in profile, without obvious division into dorsum and declivity. Petiole node in profile small, low and subconical, with a low lobe-like anteroventral process which tapers out posteriorly. Postpetiole smaller than petiole, slightly more broadly rounded above. All dorsal surfaces of head and body with standing hairs, the promesonotum with 6-7 pairs. Sculpture absent except for scattered minute hair-pits and metanotal cross-ribs. Colour yellow.

Type Material
Holotype worker, Kenya: Tana Riv., Kora, 0-100 m, no. 5, 1983, Acacia-Commiphila scrub (N. M. Collins & M. Ritchie).

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.