Messor creticus

An Alpine species recorded only form areas located above 1000 m. Nesting in soil, most often in humid, open areas, e.g., pastures or fields. Workers most active at nightfall, collecting seeds from ground or herbs. Colonies monogynous.

Identification
Messor creticus is most similar to Messor caducus and is easily distinguished from most of Mediterranean Messor in having mostly smooth and shiny head surface, more than 10 thick, erect setae on promesonotal dorsum, sparse and short erect setae on the first gastral tergite and presence of additional reticulation between striae covering surface of mesosoma. From M. caducus, it differs in lack of distinct psammophores. M. creticus has ventral head surface covered with long, thin setae that are only slightly curved on their upper part and do not form a shape characteristic for psammophores.

Distribution
Endemic to Crete.

Distribution based on Regional Taxon Lists
Palaearctic Region: Greece.

Nomenclature

 * . Messor creticus Salata & Borowiec, 2019a: 58, figs. 9-12 (s.w.) GREECE (Crete I.).
 * Type-material: holotype worker, 22 paratype workers, 1 paratype queen.
 * Type-locality: holotype Greece: W Crete I., 1034, Omalos Plateau, 35°20’N, 23°53’E, 3.v.2011, LBC-GR00505 (L. Borowiec); paratypes with same data.
 * Type-depositories: DBET (holotype); DBET, NHMC (paratypes).
 * Distribution: Greece (Crete)

Type Material

 * Holotype (w.): Collection L. Borowiec | Formicidae | LBC-GR00505 || GREECE W Crete, 1034 | Omalos Plateau | 35°20′N/23°53′E | 3 V 2011. L. Borowiec
 * Paratypes (22w., 1g.): the same locality as holotype (Natural History Museum of Crete, Heraklion, Greece).

Taxonomic Notes
This species was misidentified as Messor caducus by Borowiec and Salata, 2012: 512.

Worker
Salata and Borowiec (2019) - (n = 15): HL: 1.975 ± 0.2 (1.658– 2.289); HW: 2.092 ± 0.22 (1.789–2.461); SL: 1.487 ± 0.1 (1.316–1.632); EL: 0.383 ± 0.03 (0.342–0.447); EW: 0.272 ± 0.03 (0.237–0.316); ML: 2.364 ± 0.2 (2.039–2.774); PSL: 0.349 ± 0.04 (0.289–0.421); SDL: 0.345 ± 0.04 (0.276– 0.408); PL: 0.695 ± 0.07 (0.605–0.829); PPL: 0.434 ± 0.04 (0.368–0.487); PH: 0.506 ± 0.05 (0.434–0.579); PPH: 0.547 ± 0.06 (0.461–0.645); PNW: 1.253 ± 0.1 (1.026–1.447); PW: 0.424 ± 0.06 (0.342–0.566); PPW: 0.551 ± 0.09 (0.421–0.75); HI: 104.1 ± 5.5 (100.3–109.1); SI1: 75.7 ± 4.5 (62.1–82.4); SI2: 73.4 ± 3.7 (68.5–79.4); MI: 71.2 ± 2.9 (63.6–74.2); EI1: 71.2 ± 3.5 (65.5–76.9); EI2: 13.9 ± 0.7 (13.1–15.3); PI: 137.5 ± 4.2 (130.0–143.2); PPI: 79.7 ± 4.0 (73.6–85.7).

Color. Head and gaster black, sometimes malar area and mandibles brick–reddish. Mesosoma brick–reddish with darker coloration on sutures or in the same coloration as gaster. Petiole and postpetiole black, sometimes peduncle brick–reddish. Antennae dark brown, with brick–reddish scape apex. Legs in the same coloration as mesosoma or black. Head. Square, nearly as long as wide, lateral surfaces below and above eyes gently convex, posterior edges convex, occipital margin of head concave. Anterior margin of the clypeus slightly convex and dentate on its central part. Eyes moderate, oval, 1.4 times as long as wide. Antennal scape short, in lateral view curved, 0.8 times as long as length of the head, in apex gradually widened, its base with distinct, triangular tooth, funiculus long. Surface of scape with very sparse punctation, shiny, covered with thin, moderate dense, decumbent to erect setae. Mandibles rounded with thick sparse, longitudinal striae, shiny. Clypeus shiny with thick, longitudinal striae, area between striae shiny. Frontal carinae short, not extending beyond frontal lobes. Antennal fossa shallow, with sparse, thin, and weak roundly curved striae, area between striae with sparse and fine microreticulation, shiny. Frontal lobes narrow, smooth with slight, dense longitudinal striation. Whole head shiny with very sparse and fine microreticulation, only single, thin, longitudinal wrinkles appear on the anterior part of frons center and malar area. The whole head surface covered with short, adpressed to suberect, and thick setae; frons and vertex with a few additional erect, thick setae; ventral surface of head with dense layer of thin, erect, slightly curved setae. Mesosoma. Short, 1.9 times as long as wide; metanotal groove deep. Pronotum convex on sides. In lateral view promesonotum arched in profile, propodeum positioned lower than promesonotum, its dorsum flat and leaning towards its declivity, propodeum with very low lobe-like projections or unarmed, its ventral surface slightly concave. Whole mesosoma shiny, with dense striation, transverse on sides and irregular to transverse on dorsum. Area between striae with irregular rugosity. Mesosoma dorsum with at least 10 thick, long, and straight setae. Petiole. In lateral view, with moderate peduncle, node high, with anterior face concave, posterior face straight and dorsum steep arched. Peduncle and petiolar node shiny, with dense reticulation, dorsum with sparser reticulation. Dorsal surface bearing sparse, ling, thick, erect setae. Postpetiole. In lateral view, regularly convex, apical half with convex sides, on the whole surface shiny, with dense reticulation, dorsum with reticulation reduced. Dorsal surface bearing sparse, long, erect setae. Gaster. Shiny, with sparse microreticulation, bearing more than 10 erect, thin, pale setae.

References based on Global Ant Biodiversity Informatics

 * Agosti, D. and C.A. Collingwood. 1987. A provisional list of the Balkan ants (Hym. Formicidae) and a key to the worker caste. I. Synonymic list. Mitteilungen der Schweizerischen Entomologischen Gesellschaft, 60: 51-62
 * 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.
 * 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
 * Salata S., and L. Borowiec. 2019. Preliminary contributions toward a revision of Greek Messor Forel, 1890 (Hymenoptera: Formicidae). Turkish Journal of Zoology 43: 52-67.