Messor regalis

Some aspects of the biology of regalis have been investigated by Levieux & Diomande (1978) and Levieux (1979).

Identification
Easily characterized by its blanketing coarse rugose sculpture. No other species in the region has sculpture approaching that found in regalis. This feature coupled with the dense pilosity and persistent propodeal spines renders the species quickly recognizable. Only Messor cephalotes and regalis have extensive sculpture on the first gastral tergite; characters separating the two are given under cephalotes. (Bolton 1982)

Distribution
West and Central Africa.

Distribution based on Regional Taxon Lists
Afrotropical Region: Benin, Congo, Ivory Coast, Nigeria.

Nomenclature

 *  regalis. Cratomyrmex regalis Emery, 1892d: 572, pl. 15, fig. 16 (q.) NIGERIA. Santschi, 1913c: 307 (w.). Combination in Messor (Cratomyrmex): Santschi, 1920d: 377. Senior synonym of rubea, sculpturatus: Bolton, 1982: 352.
 * rubea. Cratomyrmex regalis var. rubea Santschi, 1913c: 308 (w.) BENIN. [Misspelled as rubra by Emery, 1921f: 43.] Junior synonym of regalis: Bolton, 1982: 352.
 * sculpturatus. Cratomyrmex sculpturatus Stitz, 1916: 377, fig. 2 (w.) CONGO. Subspecies of regalis: Santschi, 1920d: 378 (in text); Wheeler, W.M. 1922a: 802. Junior synonym of regalis: Bolton, 1982: 352.

Worker
Bolton (1982) - Medium to Large, HW 3.00- > 4.50.

Median portion of clypeus with anterior margin shallowly convex to somewhat flattened, Irregular because of strong sculpture but not strongly impressed-concave. In HW range 3.00-4.40 the maximum diameter of the eye is 0.48-0.70, about 0.16-0.17 x HW, and the CI range is 109-115. With the head in full-face view the sides in front of the eyes more or less straight, roughly parallel or slightly convergent anteriorly. Behind the eyes the sides rounding very broadly and evenly into the occipital margin; the latter usually shallowly indented medially. Propodeum armed with a pair of short triangular spines. Dorsum of head densely sculptured everywhere with coarse parallel longitudinal rugulae. On the median strip behind the frontal lobes the rugulae tend to run straight back on the head; on each side of this strip they diverge towards the occipital corners. Pronotal dorsum coarsely sharply and irregularly rugose, frequently reticulate-rugose in places and generally with a strip of strong transverse rugae immediately behind the cervical shield. Remainder of dorsum and also sides of alitrunk strongly and generally sharply rugose everywhere, the sculpture stronger than on the dorsum of the head. Tergal portions of petiole and post petiole very closely and coarsely irregularly rugose, the surfaces with a crumpled and wrinkled appearance. First gastral tergite rugulose to sharply costulate basally, the sculpture extending at least over the basal third of the sclerite and becoming finer posteriorly. All dorsal surfaces of head and body with numerous standing hairs, pilosity also dense on legs. With the head in full-face view projecting hairs are present on the sides behind the eyes, on the broad curve of the occipital corners and on the occipital margin itself. One or two hairs usually also project from the sides in front of the eyes. Psammophore conspicuously developed. Colour dull red to reddish brown, the gaster sometimes with an orange tint.

References based on Global Ant Biodiversity Informatics

 * 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.
 * Emery C. 1892. Voyage de M. Ch. Alluaud dans le territoire d'Assinie (Afrique occidentale) en juillet et août 1886. Formicides. Annales de la Société Entomologique de France 60: 553-574.
 * IZIKO South Africa Museum Collection
 * Medler J. T. 1980: Insects of Nigeria - Check list and bibliography. Mem. Amer. Ent. Inst. 30: i-vii, 1-919.
 * Santschi F. 1913. Glanures de fourmis africaines. Annales de la Société Entomologique de Belgique 57: 302-314.
 * Santschi F. 1914. Formicides de l'Afrique occidentale et australe du voyage de Mr. le Professeur F. Silvestri. Bollettino del Laboratorio di Zoologia Generale e Agraria della Reale Scuola Superiore d'Agricoltura. Portici 8: 309-385.
 * Stitz H. 1916. Formiciden. Ergebnisse der Zweiten Deutschen Zentral-Afrika Expedition 1: 369-405.
 * Tchibozo S., and N. Kaminski. 2006. Note on the social bugs of Benin, West Africa. IUSSI meeting, Washington DC, August 1st 2006.
 * 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