Trichomyrmex chobauti

Bolton (1987) noted the strongly truncated clypeus of this species may be related in some way to its strictly granivorous diet, as may the strong psammophore of very long ammochaete hairs which arises on the flat ventral surface of the head. Collingwood and Agosti (1996) reported this species is comparatively uncommon.

Identification
Sharaf et al. (2016) - Trichomyrmex chobauti is closest to Trichomyrmex almosayari and Trichomyrmex lameerei. All three species share the abundant long ammochaete J-shaped hairs that form a distinct psammophore on the underside of the head. Trichomyrmex chobauti can be readily separated from T. almosayari by the bicoloured body, the oval eyes, and the straight or feebly concave posterior margin of the head. From T. lameerei it can be distinguished by the smaller size, the longer antennal scapes that reach the posterior margin of the head, and the unsculptured posterior half of the head.

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

Nomenclature

 * . Holcomyrmex chobauti Emery, 1896j: 418, fig. (w.) ALGERIA.
 * Type-material: 2 syntype workers.
 * Type-locality: Algeria: Biskra, iv.1895 (Chobaut).
 * Type-depository: MSNG.
 * Délye, 1961: 69 (q.m.).
 * Combination in Monomorium: Emery, 1908h: 672;
 * combination in M. (Equestrimessor): Santschi, 1919d: 92;
 * combination in M. (Xeromyrmex): Emery, 1922e: 176;
 * combination in Trichomyrmex: Ward, et al. 2015: 76.
 * Status as species: Forel, 1902a: 150; Emery, 1908h: 672; Emery, 1922e: 176; Menozzi, 1929e: 127; Délye, 1961: 69; Ettershank, 1966: 88; Bolton, 1987: 297; Bolton, 1995b: 260; Collingwood & Agosti, 1996: 344; Cagniant, 2006a: 196; Collingwood, et al. 2011: 433; Borowiec, L. 2014: 117 (see note in bibliography); Sharaf, Salman, et al. 2016a: 14 (redescription).
 * Senior synonym of faf: Emery, 1922e: 176; Délye, 1961: 69; Bolton, 1995b: 260 Sharaf, Salman, et al. 2016a: 14.
 * Distribution: Algeria, Libya, Morocco, Saudi Arabia, Tunisia, United Arab Emirates.
 * Current subspecies: nominal plus ajjer.
 * faf. Holcomyrmex faf Forel, 1902a: 151 (q.m.) ALGERIA.
 * Type-material: 1 syntype queen, 1 syntype male (in copula).
 * Type-locality: Algeria: “probably at Biskra”, iii.-iv.1888 (F.-A. Forel).
 * Type-depository: MHNG.
 * Combination in Monomorium: Emery, 1908h: 673.
 * Status as species: Emery, 1908h: 673.
 * Junior synonym of chobauti: Emery, 1922e: 176; Délye, 1961: 69; Bolton, 1995b: 261 Sharaf, Salman, et al. 2016a: 12.

Worker
Sharaf et al. (2016) - TL 3.27; HL 0.88; HW 0.88; SL 0.72; EL 0.16; ML 1.22; PW 0.45; PTL 0.28; PTW 0.30; PPL 0.25; CI 100; El 18; SI 82.

Head. As long as broad, with feebly concave posterior margin and weakly convex sides; anterior clypeal margin distinctly concave; eyes of moderate size (EL 0.18 × HW) with 11 ommatidia in longest row; scapes when laid back from their insertions reach posterior margin of head.

Mesosoma. Promesonotum convex in profile, running back to straight mesonotum; metanotal groove impressed; propodeal dorsum nearly twice as long as declivity in profile; propodeal spiracle circular, situated above midline of propodeum in profile.

Petiole. Petiolar node rounded in profile.

Postpetiole. Node low and broad in profile.

Pilosity. Underside of head with long ammochaete J-shaped hairs forming a distinct psammophore; cephalic dorsum with sparse suberect hairs directed inward to midline of head; antennae with dense appressed pubescence; anterior clypeal margin with abundant long curved hairs; pilosity on mesosoma restricted to two or three pairs of hairs on pronotum and promesonotum; sparse decumbent pubescence on mesonotal and propodeal dorsum; petiole and postpetiole bare; gastral tergites with sparse appressed pubescence, few longer pairs of hairs present at gastral apex.

Sculpture. Clypeus, mandibles, and cephalic surface between frontal carinae and in front of eyes longitudinally rugulose; promesonotum and mesonotum faintly longitudinally rugulose; propodeum and sides of mesonotum, petiole and postpetiole densely punctulate-reticulate, gaster smooth and shining.

Colour. Head, mesosoma, petiole and postpetiole reddish brown, gaster dark brown.

Type Material
Sharaf et al. (2016) - Algeria: Palearctic. Syntype worker (CASENT0904606) [examined].

References based on Global Ant Biodiversity Informatics

 * Barech G., M. Khaldi, X. Espadaler, and H. Cagniant. 2017. The genus Monomorium Mayr, 1855 (Hymenoptera, Formicidae) in the Maghreb (North Africa): Identification key, redescription of Monomorium major Bernard, 1953 and new records from Algeria. Boletin de la Sociedad Entomológica Aragonesa 61: 151-157.
 * Borowiec L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
 * Cagniant, H. "Liste actualisee des fourmis du Maroc (Hymenoptera: Formicidae)." Myrmecologische Nachrichten 8 (2006): 193-200.
 * 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
 * Délye G. 1964. Sur le peuplement myrmécologique de quelques ergs du Sahara nord-occidental. Travaux de l'Institut de Recherches Sahariennes 23: 165-170.
 * Délye, G., and J. C. Bonaric. "Les fourmis arenicoles du sud marocain (Hym. formicidae)." Bulletin de la Société Entomologique de France 3 (1973): 107-110.
 * Délye, G. "Répartition des fourmis dans les grands massifs de dunes du Sahara nord-occidental (Hym.)." Bulletin de la Société Entomologique de France 74 (1970): 224-227.
 * Emery, C. "Beiträge zur Monographie der Formiciden des paläarktischen Faunengebietes. (Hym.) Teil V. Monomorium." Deutsche Entomologische Zeitschrift 1908 (1908): 663-686.
 * Emery, C. "Description d'une fourmi nouvelle d'Algérie (Hymén.)." Bulletin de la Société Entomologique de France 1896 (1897): 418-419.
 * Ettershank G. 1966. A generic revision of the world Myrmicinae related to Solenopsis and Pheidologeton (Hymenoptera: Formicidae). Aust. J. Zool. 14: 73-171.
 * Forel, A. "Les fourmis du Sahara algérien récoltées par M. le Professeur A. Lameere et le Dr. A. Diehl." Annales de la Société Entomologique de Belgique 46 (1902): 147-158.
 * Sharaf M. R., S. Salman, H. M. Al Dhafer, S. A. Akbar, M. S. Abdel-Dayem, A. S. Aldawood. 2016. Taxonomy and distribution of the genus Trichomyrmex Mayr, 1865 (Hymenoptera: Formicidae) in the Arabian Peninsula, with the description of two new species. European Journal of Taxonomy 246: 1–36