Messor decipiens

Identification
Very closely related to Messor capensis and Messor piceus, decipiens is separated from the former only on the weak characters (see the worker section under the nomenclature heading below). It is even closer to the latter, being distinguished only by the colour of the hairs (dark pilosity in piceus; pale, white or silverish in decipiens), and the fact that piceus does not have the head distinctly different in colour from the alitrunk in large workers. It seems very probable that more extensive collecting of this complex will reveal that these forms represent but a single species. (Bolton 1982)

Distribution based on Regional Taxon Lists
Afrotropical Region: Botswana, Lesotho, Saudi Arabia, South Africa, Zimbabwe. Palaearctic Region: Iraq.

It is known to occur in South and East Africa, Saudi Arabia and Iraq (Abdul-Rassoul et al. 2013).

Nomenclature

 *  decipiens. Messor capensis st. decipiens Santschi, 1917e: 94 (w.q.) SOUTH AFRICA. [First available use of Stenamma (Messor) barbarum r. capense var. decipiens Forel, 1905b: 177; unavailable name.] Raised to species and senior synonym of arcistriatus, probus: Bolton, 1982: 348.
 * probus. Messor capensis var. probus Wheeler, W.M. 1922a: 805 (w.) SOUTH AFRICA. [First available use of Messor barbarus subsp. capensis var. proba Forel, 1911e: 266; unavailable name.] Junior synonym of decipiens: Bolton, 1982: 348.
 * arcistriatus. Messor arcistriatus Santschi, 1928f: 202 (w.) SOUTH AFRICA. Junior synonym of decipiens: Bolton, 1982: 348.

Worker
Bolton (1982) - Medium to Large, HW 2.64- > 4.20.

Answering to the description of Messor capensis in most particulars. In the HW range quoted above the maximum diameter of the eye is 0.44-0.66, about 0.14-0.18 x HW, and the CI range is 107-121, the largest workers known for decipiens thus being somewhat larger and broader headed than those known for capensis. Propodeum in profile with the dorsum usually meeting the declivity in a right-angle, which may project into a broad but quite short lobe or tooth of variable shape and size; rarely the propodeum merely narrowly rounded. In contrast the propodeum of capensis is generally rounded, only seldom with dentiform prominences. Sculpture of head basically the same as in capensis but here the rugae tending to be more sharply developed and more widely separated, although there is some variation. Spaces between the rugae usually smooth, frequently glossy, much less commonly with traces of punctulate ground-sculpture. Head usually obviously red, contrasting in colour with the alitrunk and gaster which are darker. In smaller workers this distinction in colour is not nearly so obvious and at the lower limit of the size range considered here (and smaller) the ant may be unicoloured.

References based on Global Ant Biodiversity Informatics

 * Abdul-Rassoul M. S., H. B. Ali, and R. SH. Augul. 2013. New Records of Unidentified Ants worker (Hymenoptera: Formicidae: Myrmicinae) stored in Iraqi Natural History Museum with key to Species. Adv. Biores., Vol 4 (2): 27-33.
 * Arnold G. 1920. A monograph of the Formicidae of South Africa. Part IV. Myrmicinae. Annals of the South African Museum. 14: 403-578.
 * Bolton B. 1982. Afrotropical species of the myrmicine ant genera Cardiocondyla, Leptothorax, Melissotarsus, Messor and Cataulacus (Formicidae). Bulletin of the British Museum (Natural History). Entomology 45: 307-370.
 * Borowiec L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
 * Forel A. 1905. Miscellanea myrmécologiques II (1905). Ann. Soc. Entomol. Belg. 49: 155-185.
 * Forel A. 1911. Die Ameisen des K. Zoologischen Museums in München. Sitzungsber. Math.-Phys. Kl. K. Bayer. Akad. Wiss. Münch. 11: 249-303.
 * IZIKO South Africa Museum Collection
 * Santschi F. 1928. Descriptions de nouvelles fourmis éthiopiennes (suite). Revue de Zoologie et de Botanique Africaines. 16: 191-213.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004