Metalasius myrmidon

Identification
Definition (worker) (Boudinot et al., 2022).
 * 1) With character states of Metalasius.
 * 2) Dorsal mandibular groove absent (see Boudinot et al. (2022), Note 1).
 * 3) Ventromedial base of mandible without trough or impression (see Boudinot et al. (2022), Note 2).
 * 4) Maxillary palps short, exceeding hypostomal margin but not reaching postgenal bridge midlength.
 * 5) Maxillary palpomere 3 longest, 4 shorter but as long as 5 and 6 together (see Boudinot et al. (2022), Note 3).
 * 6) Clypeus, in lateral view, convex and weakly bulging anteriorly (see Boudinot et al. (2022), Note 3).
 * 7) Anterior tentorial pit situated lateral to midlength of the epistomal suture.
 * 8) Lateral hypostomal carina absent (see Boudinot et al. (2022), Note 4).
 * 9) Compound eyes absent, reduced or vestigial, with at most 9 ommatidia (see Boudinot et al. (2022), Note 5).
 * 10) Propodeal spiracle situated distinctly in lower half of propodeum (see Boudinot et al. (2022), Note 6).
 * 11) Legs almost entirely devoid of standing setae (see Boudinot et al. (2022), Note 3).
 * 12) Petiolar node weakly inclined anteriorly, node well-developed, squamiform (see Boudinot et al. (2022), Note 7).

Metalasius myrmidon is uniquely identified among the Lasiini by:
 * absence of the dorsal mandibular groove and lateral hypostomal carina
 * short and broad third antennomere
 * mid-set compound eyes (when present), which are reduced to at most 9 ommatidia
 * near complete absence of standing setae on the head.

Note that high magnification may be required to evaluate the lateral hypostoma.

Distribution based on Regional Taxon Lists
Palaearctic Region: Greece.

Nomenclature

 *  myrmidon. Lasius myrmidon Mei, 1998: 177, figs. 1-11 (w.) GREECE.
 * Combination in Metalasius: Boudinot et al., 2022: 140.

References based on Global Ant Biodiversity Informatics

 * Borowiec L. 2014. Catalogue of ants of Europe, the Mediterranean Basin and adjacent regions (Hymenoptera: Formicidae). Genus (Wroclaw) 25(1-2): 1-340.
 * Borowiec L., and S. Salata. 2012. Ants of Greece - Checklist, comments and new faunistic data (Hymenoptera: Formicidae). Genus 23(4): 461-563.
 * Borowiec L., and S. Salata. 2017. Ants of the Peloponnese, Greece (Hymenoptera: Formicidae). Polish Journal of Entomology 86: 193-236.
 * Czechowski W., A. Radchenko, W. Czechowska and K. Vepsäläinen. 2012. The ants of Poland with reference to the myrmecofauna of Europe. Fauna Poloniae 4. Warsaw: Natura Optima Dux Foundation, 1-496 pp
 * Mei, M.. "Lasius (Cautolasius) myrmidon n. sp.: A new hypogaeic ant from Greece (Hymenoptera, Formicidae)." Bollettino della Societa Entomologica Italiana 130 (1998): 177-182.