Technomyrmex vexatus

Technomyrmex vexatus, is only known from Ceuta, Tangier and Gibraltar. In Gibraltar it is only found in the Gibraltar Botanic Gardens or surrounding areas where a large number of exotic plants are present. Tinaut’s (1989) survey in the vicinity of Gibraltar and other expeditions in the Spanish shore of the Strait have never found it there (Guillem & Bensusan, 2008). T. vexatus has a similar distribution pattern as Stigmatomma emeryi and Anochetus ghilianii, occurring on both sides of the Strait of Gibraltar and having a very restricted range on at least one side of the strait. A genetic study (Jowers et al. 2015) suggested the distribution of A. ghilianii is not explained by this species having been present prior to the closing of a land connection between these two areas, i.e., > 5 MYA. It was more likely moved across the strait by humans. They speculated the distribution of Technomyrmex vexatus has a similar explanation.

Identification
Bolton (2007) - A member of the Technomyrmex gibbosus group. The closest known relative of vexatus is the east Palaearctic Technomyrmex gibbosus, which it clearly resembles. However, in gibbosus the eyes are larger and located distinctly farther forward on the head capsule (gibbosus OI 27 - 29, EPI 50 - 58) and the posterior cephalic margin is indented medially.

Distribution
Sharaf et al. (2018): Technomyrmex vexatus was originally described from Morocco. This species seems to exist as a series of isolated populations in rather restricted and specialized habitats throughout North Africa and eastward into the Arabian Peninsula, and perhaps Iran (B. Bolton, pers. comm.). Two species of the T. gibbosus-group are known from the Arabian Peninsula, the above record of T. vexatus from Yemen and T. montaseri from Oman. Technomyrmex vexatus was recorded for the first time from Palearctic (Gibraltar) by Guillem and Bensusan (2008).

Distribution based on Regional Taxon Lists
Palaearctic Region: Gibraltar, Morocco.

Biology
Bolton (2007) - Described from males. Dr. Xavier Espadaler (UABC) collected a Technomyrmex colony in Morocco in 1986 and reared it In his laboratory. In 1988 this colony produced males which have proved identical to the syntypes.

The closest relative of this species, the eastern Palaearctic Technomyrmex gibbosus, is separated from vexatus by an enormous distance. It is interesting to speculate if they shared an immediate common ancestor, or if they are the remnants of a fairly distinctive species group that once extended across the width of the southern Palaearctic, or if each has acquired the shared characters by convergence from unrelated ancestors.

Nomenclature

 *  vexatus. Tapinoma vexatum Santschi, 1919i: 220 (footnote) (m.) MOROCCO. Bolton, 2007a: 40 (w.). Combination in T. (Tapinoptera): Santschi, 1925g: 348; in Technomyrmex: Cagniant & Espadaler, 1993: 92.

Worker
Bolton (2007) - TL 3.1 - 3.4, HL 0.72 - 0.78, HW 0.68 - 0.76, SL 0.64 - 0.70, PW 0.44 - 0.48, WL 0.90 - 0.96 (10 measured). Indices: CI 94 - 99, SI 90 - 94, OI 22 - 25, EPI 68 - 76, DTI 118 - 130.

Dorsum of head behind clypeus entirely lacks setae. Anterior clypeal margin with an insignificant median indentation to almost transverse. In full-face view the posterior margin of the head very shallowly impressed and the sides shallowly convex. Eyes of moderate size, close to midlength and their outer margins just fail to break the outline of the sides. Sculpture of head very weak and superficial, an effaced microreticulation. Dorsum of mesosoma and propodeal declivity entirely lack setae. With mesosoma in profile the mesonotal dorsal outline consists of an anterior section that is short and flat to feebly convex; posterior to this the surface curves broadly and evenly into a longer, more steeply sloped posterior section that descends to the narrow metanotal groove. Propodeum in profile with a short convex dorsal surface that rounds evenly into the declivitv. the two surfaces not separated by an angle. Sculpture reduced and superficial on dorsal mesosoma and first gastral tergite; pubescence on the latter very short and sparse, not masking the surface of the sclerite. Gastral tergites 1 - 3 without setae; gastral tergite 4 with 2 - 3 pairs/resent. Scapes and tibiae without setae. Colour a uniform medium brown; the hea sometimes, and the gaster usually, very slightly darker than the mesosoma. Legs also brown, the middle and hind tarsi slightly lighter than the femora and tibiae.

Type Material
Syntype males, Morocco: Tanger, 1897 (Vaucher) [examined].