Oxyopomyrmex

Oxyopomyrmex is a small genus of myrmicine ants found in arid grasslands of the Mediterranean region. It is most species-rich in northwest Africa.

Identification
Salata and Borowiec (2015) - This genus is easily distinguished from other Mediterranean genera by having (1) characteristic large eyes, pointed anteroventrally, with anterior margin close to the mandibular insertions and (2) 11-segmented antennae. Goniomma, which is very similar in appearance, differs from Oxyopomyrmex by having 12-segmented antennae and a geographic distribution limited to the western part of the Mediterranean region. However, a high level of similarity in morphology and biology of both genera, supported by results of the molecular phylogeny in Ward et al. (2015), may question the validity of the separation of Goniomma from Oxyopomyrmex. Determination of the relationship between these genera requires further study.

Distribution
Salata and Borowiec (2015) - Previous literature had suggested that most Oxyopomyrmex species occur in the western part of the Mediterranean area sensu lato (including the Canary Islands and the adjacent areas of the Middle East). This revision has shown that they are evenly spread in the whole Mediterranean basin with six species in both the western and eastern parts of the region. Three species have a wide range: Oxyopomyrmex nitidior (North Africa), Oxyopomyrmex krueperi (north-eastern part of the Mediterranean Basin and the Near East) and Oxyopomyrmex saulcyi (north-western part of the North Africa, Iberian Peninsula, France and Sicily). Other species of this genus have either very limited ranges or they are island endemics. We identify two centers of diversity for the genus: one in the northwestern part of North Africa and the other one in the eastern part of the Mediterranean Basin.

Species richness
Species richness by country based on regional taxon lists (countries with darker colours are more species-rich). View Data



Biology
Salata and Borowiec (2015) - The biology of Oxyopomyrmex species is poorly known and usually limited to short notes in the descriptions of species, checklists and catalogues. Members of this genus prefer open, grassy, arid environments with sparse vegetation (Forel 1904, Santschi 1910) and most species are cryptic, nocturnal seed harvesters (Espadaler 1981, Hansen 2002, Reyes 1986, Wheeler 1907). Nests are located in soil (usually sand or clay), sometimes under stones. In most species the nest entrance is surrounded by a small crater composed of herb scraps (Bernard 1967, Déyle 1971, Forel 1904, Menozzi 1936).

Nomenclature

 *  OXYOPOMYRMEX [Myrmicinae: Pheidolini]
 * Oxyopomyrmex André, 1881b: 72. Type-species: Oxyopomyrmex oculatus, by monotypy.

Salata and Borowiec (2015) :

Oxyopomyrmex is a small genus of ants with a center of diversity in northwest Africa. The genus was described by André (1881) as monotypic for Oxyopomyrmex oculatus André, 1881, from Israel, and now contains 15 species-group taxa. It occurs mostly in the Mediterranean Basin with a few records from the Near East and one from Macaronesia (Ghahari et al. 2011, Borowiec 2014).

Worker
Worker small to medium sized, monomorphic. Head elongate to quadrate, longer than wide (except for O. magnus, Oxyopomyrmex emeryi, Oxyopomyrmex nitidior). Frontal carinae short, never exceeding 1/3 length of the eye. Mandible striate, with 7-8 teeth, sometimes apical tooth massive and long. Antennae 11 segmented; antennal club 3-jointed. Compound eyes large, elongate, narrowing downward, reaching anteroventral margin of head. Gena with either striae and rugae sparser than on frons or smooth, without sculpture, often shinier. Entire head bearingsetae, posterior margin with sparse to dense erect setae directed forward, lateral surfaces of the head with a few appressed to dense semierect setae always directed toward anterior margin, frontal area with sparse to dense, appressed to erect setae, placed transversely and directed to the center of the head, ventral surface of the head with a long psammophore appressed to erect long setae. Promesonotum projecting slightly higher than propodeum, flat or sometimes convex in profile. Pronotum and mesonotum always sculptured, sometimes with smooth surfaces at the center of the mesonotum. Propodeal spines always with wide base, usually triangular rising obliquely upwards. Abdomen shiny with long semierect to erect setae (except for O. negevensis).

Queen
Diagnosis. Head quadrate to rectangular, longer than wide (except for Oxyopomyrmex magnus). Frontal carinae short, never exceeding 1/3 length of the eye. Mandible striate, with 7–8 teeth, the apical tooth massive and long. Antennae 11 segmented; antennal club 3-jointed. Compound eyes large, elongate, narrowing downward, reaching anteroventral margin of head. Gena with either striae and rugae sparser than on frons or smooth, without sculpture, often shinier. Entire head bearing setae, posterior margin with sparse to dense erect setae directed forward, lateral surfaces of the head with sparse to dense semierect setae always directed toward anterior margin, frontal area with sparse to dense, appressed to erect setae, placed transversely and directed to the center of the head, ventral surface of the head with a prominent psammophore and appressed to erect long setae. Promesonotum projecting dorsally above propodeum, flat or slightly convex in profile. Scutum and scutellum always sculptured, sometimes smooth at center. Propodeal spines always with wide base, usually triangular, rising obliquely upwards. Abdomen shiny with long semierect to erect setae.

Male
Diagnosis Head oval, longer than wide. Frontal carinae short, curved outward to merge with the rugae surrounding antennal sockets. Mandible striate, with 4-5 teeth, the apical tooth massive and long. Antennae 12 segmented. Compound eyes large, oval. Gena with either striae and rugae sparser than on frons or smooth, without sculpture, often shinier. Entire head bearing setae, posterior margin with sparse to dense erect setae directed forward, lateral surfaces of the head with a few appressed to dense, semierect setae directed toward anterior margin, frontal area with sparse to dense, appressed to erect setae, placed transversely and directed to the center of the head. Ventral surface of the head with a long psammophore and appressed to erect long setae. Promesonotum projecting dorsally above propodeum, flat or slightly convex in profile. Scutum and scutellum always sculptured with three smooth longitudinal stripes at the scutum. Central stripe always shorter. Propodeal spines with wide base, short or absent. Abdomen shiny with long semierect to erect setae. No significant differences in genitalia shape and structure were observed.