Monomorium carbo

Only known from a single collection of a few workers.

Identification
Bolton (1987) - A member of the M. australe complex in the M. salomonis species group. This enigmatic Ethiopian species is only known from the type-series of a couple of workers. At first glance it appears to be related to Monomorium minor, a yellow species from Namibia and Angola which itself seems to be intermediate between this complex and the viator-complex, but the wide separation of their habitats and the differences in their scape indices stand against this apparent relationship. Fresh material will have to be obtained before a clear picture of what constitutes S. carbo can be developed.

Distribution based on Regional Taxon Lists
Afrotropical Region: Eritrea, Saudi Arabia, United Arab Emirates. Palaearctic Region: Ethiopia, Oman.

Castes
Queens and males are unknown.

Nomenclature

 * . Monomorium salomonis var. carbo Forel, 1910c: 251 (w.) ERITREA.
 * Type-material: syntype workers (number not stated).
 * Type-locality: Eritrea: Ghinda, 1906 (K. Escherich).
 * Type-depository: MHNG.
 * Combination in M. (Xeromyrmex): Wheeler, W.M. 1922a: 870.
 * Subspecies of salomonis: Forel, 1914d: 246; Wheeler, W.M. 1922a: 870; Emery, 1922e: 178; Finzi, 1939a: 164; Ettershank, 1966: 88.
 * Status as species: Santschi, 1936a: 39; Bolton, 1987: 339 (redescription); Bolton, 1995b: 260; Collingwood & Agosti, 1996: 343; Collingwood, et al. 2011: 433; Borowiec, L. 2014: 117; Madl, 2019: 15.
 * Distribution: Egypt, Eritrea, Oman, Saudi Arabia, United Arab Emirates.

Worker
Bolton (1987) - TL 2.3-2.4, HL 0.60-0.63, HW 0.43-0.45, CI 71-72, SL 0.44-0.48, SI 102-107, PW 0.30-0.31, AL 0.66-0.70 (2 measured).

Anterior margin of median portion of clypeus shallowly concave. With head in full-face view the sides weakly divergent from back to front, the occipital margin shallowly concave. Maximum diameter of eye 0.24-0.26 x HW and with 7 ommatidia in the longest row. The eyes very slightly in front of the midlength of the sides. Metanotal groove scarcely impressed in profile, the propodeal dorsum flattened to weakly depressed medially, without sharp lateral margins. Occipital margin of head with a pair of hairs straddling the midline and another pair closer to the occipital corners. Dorsal alitrunk without hairs. Petiole and postpetiole each with 1-2 pairs of backward directed hairs. First gastral tergite with numerous hairs which are evenly distributed over the surface in front of the apical transverse row. Dorsum of head opaque, shagreenate-punctulate everywhere. Dorsal alitrunk finely reticulate-punctate, the sides similarly sculptured but somewhat effaced on the sides of the pronotum. First gastral tergite shining, with superficial reticular patterning only. Colour uniform dark brown to blackish brown.

Type Material
Monomorium salomonis var. carbo Forel, 1910d: 251. Syntype workers, ETHIOPIA: Ghinda (K. Escherich) [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.
 * Borowiec L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
 * Collingwood C. A., D. Agosti, M. R. Sharaf, A. Van Harten, 2011. Order Hymenoptera, family Formicidae. Arthropod Fauna of the UAE 4: 405-474
 * Collingwood C.A., D.Agosti, M.R. Sharaf, and A. van Harten. 2011. Order Hymenoptera, family Formicidae. Arthropod fauna of the UAE, 4: 405474
 * Emery C. 1915. Formiche raccolte nell'Eritrea dal Prof. F. Silvestri. Bollettino del Laboratorio di Zoologia Generale e Agraria della Reale Scuola Superiore d'Agricoltura. Portici 10: 3-26.
 * Ettershank G. 1966. A generic revision of the world Myrmicinae related to Solenopsis and Pheidologeton (Hymenoptera: Formicidae). Aust. J. Zool. 14: 73-171.
 * Finzi B. 1939. Materiali zoologici dell'Eritrea raccolti da G. Müller durante la spedizione dell'Istituto Sieroterapico Milanese e conservati al Museo di Trieste. Parte III. Hymenoptera: Formicidae. Atti del Museo Civico di Storia Naturale di Trieste 14: 153-168.
 * Forel A. 1910. Ameisen aus der Kolonie Erythräa. Gesammelt von Prof. Dr. K. Escherich (nebst einigen in West-Abessinien von Herrn A. Ilg gesammelten Ameisen). Zoologische Jahrbücher. Abteilung für Systematik, Geographie und Biologie der Tiere 29: 243-274.
 * Madl M. 2019. Notes on the ant fauna of Eritrea (Insecta: Hymenoptera: Formicidae): type specimens deposited in the Natural History Museum Vienna (Austria) and a preliminary checklist. Ann. Naturhist. Mus. Wien, B 121: 9-18.
 * Sharaf M. R., B. L. Fisher, H. M. Al Dhafer, A. Polaszek, and A. S. Aldawood. 2018. Additions to the ant fauna (Hymenoptera: Formicidae) of Oman: an updated list, new records and a description of two new species. Asian Myrmecology 10: e010004
 * 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