Monomorium borlei

One of the few known collections of this species was found in a forest litter sample.

Identification
Bolton (1987) - A member of the M. leopoldinum complex in the M. monomorium species group. Related to Monomorium leopoldinum (=Monomorium madecassum) but differentiated by its longer scapes and much sparser pilosity, borlei is known only from the type-series. Originally described as a variety of Monomorium springvalense, borlei is very close indeed to that species but is darker in colour, has a larger propodeal spiracle and 3 pairs of standing hairs on the promesonotum.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola.

Nomenclature

 *  borlei. Monomorium (Monomorium) springvalense var. borlei Santschi, 1937d: 227, figs. 22-24 (w.) ANGOLA. Raised to species: Bolton, 1987: 381.

Worker
Bolton (1987) - TL 1.9-2.0, HL 0.50-0.52, HW 0.40-0.41, CI 79-80, SL 0.36-0.38, SI 90-93, PW 0.25-0.26, AL 0.54-0.56 (2 measured).

Median portion of clypeus sharply prominent anteriorly, the anterior and lateral borders of the prominence separated by obtuse but sharp angles and the anterior margin between the angles shallowly concave. Clypeal carinae moderately sharply defined, widely divergent anteriorly. Maximum diameter of eyes 0.22-0.24 x HW and with 7 ommatidia in the longest row. With the head in full-face view the eyes in front of the midlength of the sides and the antennal scapes, when laid straight back, failing to reach the occipital margin. In full-face view the sides of the head very feebly convex, the occipital margin broad and transverse to extremely shallowly concave. Promesonotum in profile convex anteriorly, the mesonotum posteriorly almost flat and sloping evenly to the narrow but distinctly impressed metanotal groove. Propodeal dorsum behind the metanotal groove following the same slope as the mesonotum; rounding broadly into the declivity. Propodeal spiracle large and dominating the side of the sclerite. Petiole with a low flange-like ventral process, the node bluntly subconical. Node of postpetiole lower than that of petiole, broader and more broadly rounded above. In dorsal view both nodes conspicuously broader than long. Standing hairs sparsely present on all dorsal surfaces of head and body; the promesonotum with 3 pairs, propodeum with 1 pair, petiole and postpetiole each with 1 pair. Almost entirely smooth and unsculptured except for hair-pits; the metanotal groove with short but sharply defined cross-ribs and the mesopleuron with a transverse strip of vestigial sculpture. Colour a uniform glossy dark brown.

Type Material
Bolton (1987) - Syntype workers, Angola: Sangeve, 1932-33, no. 1 10 (A. Monard) [examined].

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.
 * Ettershank G. 1966. A generic revision of the world Myrmicinae related to Solenopsis and Pheidologeton (Hymenoptera: Formicidae). Aust. J. Zool. 14: 73-171.