Temnothorax strymonensis

This species occurs in various habitats and can be found at altitudes between 10 and 1550 m a.s.l. Most samples were collected in stream valleys with deciduous or mixed forests, open oak woodlands, and mountain pastures with phrygana and oak shrubs. Three samples were collected in montane conifer forests. Single samples were found in a pine forest, shrubs overgrowing the old monastery, on marble tombs in the old cemetery, and on pastures and limestone rocks in the alpine zone. In all localities, ants were observed or collected on limestone rocks or in oak shrubs. Nests were located mostly in shaded areas under moss or in limestone crevices. (Csosz et al. 2018). In Greece it is associated with open habitats such as rocks and stones overgrown by bushes or limestones on mountain pastures, collected also in deciduous or mixed forests, and occasionally in coniferous forests (Salata & Borowiec, 2019).

Identification
Csosz et al. (2018) - Workers and gynes of Temnothorax strymonensis differ remarkably from those of Temnothorax interruptus and can be easily separated on the basis of a couple of traits (see T. interruptus), but workers look very much like those of Temnothorax morea.

The most reliable features which help distinguish workers of Temnothorax strymonensis and T. morea are the FL / SL ratio (> 0.45 in T. strymonensis and < 0.45 in T. morea) and the shape of the transversal band on the first tergite. In T. strymonensis, the transversal band is the narrowest medially, and it gradually widens laterally. Usually, the apical band is intact, but if a narrow interruption in the central part of the band occurs, its edges are parallel. T. morea has a transverse band with a broad interruption in the central part. Interruption edges are never parallel; they are more or less V-shaped.

Gynes of Temnothorax strymonensis differ from T. morea in the following features: 1) propodeal spines (SPST / CS) are shorter than 0.3 (T. morea > 0.3); 2) the surface of the scutellum is smooth and shiny, sometimes with sparse wrinkles on its sides (T. morea has longitudinal costae, which are sparse and very gentle, covering the whole scutellum; sometimes, costae are absent on side edges); 3) very sparse, transverse, and gentle costulae and microreticulation is present above the propodeal spines (the surface above the propodeal spines lacks transverse costae and is not microreticulated).

Distribution
Csosz et al. (2018) - Temnothorax strymonensis is an East Mediterranean (Vigna Taglianti & al. 1999) species. It most typically occurs in Greece and southern Bulgaria, but it can be found in Croatia along the Adriatic Sea coast as well. This species is known to penetrate deeply into the Anatolian territories of Turkey, where it syntopically co-occurs with T. interruptus in a single locality (Prov. Kayseri, Ziyarettepesi Geçidi, ca. 130 km E. Kayseri). Despite the extensive contact zone found for T. strymonensis and T. morea in southern and western Greece, true syntopic occurrence of these species has not been observed.

Distribution based on Regional Taxon Lists
Palaearctic Region: Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Montenegro, Serbia, Turkey.

Nomenclature

 *  strymonensis. Temnothorax strymonensis Csősz, S., Salata, S. & Borowiec, L. 2018: 112, figs. 6, 9, 12, 15, 20, 21, 26, 27, 30 (w.q.) BULGARIA.

Worker
Head yellow to dark orange with brown posterior part of gena or darker orange to brown posterior part of head. Scapes same colouration as head. Funicles same colouration as scapes or pale brown. Mesosoma, legs, petiole and postpetiole yellow to dark orange. Sometimes femora slightly darker than tibiae. Gaster yellow to dark orange with brown to black, transverse, band in the apical part of the first tergite, usually narrower than ⅓ length of tergite. In most specimens the band is tapering at the middle and gradually extending on sides. Usually apical band with narrow interruption in the central part of parallel edges but often complete. In extreme form apical band is moderately broad, on sides reaching half-length of first tergite without or with median interruption but edges of the interruption more or less parallel.

Head slightly longer than broad (CL / CWb: 1.237 [1.199, 1.267]), (Figs. 12, 15). Eyes small, oval, (EL / CS: 0.251 [0.234, 0.269]). Antennal scape moderately long (SL / CS: 0.856 [0.813, 0.890]), reaching occipital margin of head.

Mesosoma elongate (ML / CS: 1.222 [1.164, 1.382]), dorsal contour line in profile slightly rounded or straight. Propodeal spines long (SPST / CS: 0.384 [0.322, 0.429]), wide at base, slightly curved downwards with pointed apex. Frontal carinae short, extending to ⅓ length of eye; antennal fossa shallow, with sparse rugosity, interstices punctate or microreticulate.

Frontal lobes distinctly wider than frons (FL / FR: 1.090 [1.040, 1.146]), with sparse rugae or costae, interstices shiny. Frons shiny, longitudinally costulate or rugose, interstices punctate or microreticulate. Postocular area of head with sparse rugosity and sometimes longitudinally costulate. Genae sometimes with sparser sculpture. Interstices punctate or densely microreticulate and shiny. Entire head bearing suberect to erect, pale and thin setae.

Dorsum of mesosoma sparsely rugulose. Lateral surface of promesonotum longitudinally costulate. Lateral surface of propodeum with weaker sculpture. Interstices shiny with dense microreticulation or micropunctation. Area between and below propodeal spines shiny and punctate, sometimes with transverse costae. Dorsal surface of mesosoma with sparse, erect, long, thick and pale setae. Entire surface of petiole and postpetiole with microrugosity to densely punctate.

Queen
Head, mesosoma, antennae, petiole, postpetiole and legs orange or bright orange. Antennal club or whole funiculus darker. Sometimes scutum and scutellum darker or bright brown. Gaster with variable colouration. Most frequently first tergite in anterior half orange and posterior half brown, remaining tergites yellow-orange basally and brown apically but apical margins always pale. Sometimes first tergite on orange anterior surface with brown spot of diffused borders. The orange colouration can be limited to ⅓ length or can take the form of a spot.

Eyes big, oval [EL / CS: 0.3 ± 0.01]. Antennal scape long [SL / CS: 0.79 ± 0.02], reaching occipital margin of head. Propodeal spines long or medium length [SPST / CS: 0.4 ± 0.05], wide at base, triangular, straight or slightly curved downward, with rounded apex. Clypeus shiny with diffuse, longitudinal wrinkles, with smooth surface between carinulae. Its central area smooth and shiny; antennal fossa deep, with sparse rugosity. Surface between rugosity with micropunctation, shiny. Frontal lobes wide [FLS / CS: 0.4 ± 0.01], rugulose with thick longitudinal costae, shiny and with micropunctation between rugosities. Frons shiny, all surface longitudinally costate and rugose, interstices microreticulate, or micropunctate, shiny. Area above eyes and sides of head with sparse, thick rugosity and sometimes with sparse, thick, longitudinal costae. Surface between rugosity with dense microreticulation or micropunctation, shiny. Genae with reduced sculpture, with dense microreticulation, shiny. Entire head bearing suberect to erect, pale and thin setae.

Pronotum with sparse rugosity on whole dorsal surface, surface between rugosity with sparse microreticulation, shiny. Sides with sparse, thick longitudinal costae or rugosity. Surface between rugosity with sparse microreticulation, shiny. Scutum with sparse, gentle longitudinal, and sometimes intermittent, costae, shiny. Sometimes main sculpture absent on the anterior surface and side edges. Scutellum entirely smooth and shiny, sometimes sides with sparse wrinkles. Metanotum smooth and shiny. Sometimes with few thick wrinkles. Propodeum with variable sculpture. Area above propodeal spines with very sparse, transverse and gentle costulae or sparse irregular rugosity, interstices microreticulate, shiny. Area between and below propodeal spines with dense punctation. Sides of propodeum with dense, gentle longitudinal costulae, interstices sparsely microreticulate or smooth, always shiny. Anepisternum, katepisternum, metaepisternum and metakatepisternum shiny, with dense, gentle, longitudinal costulae, interstices smooth or very finely microreticulate. Dorsal surface of mesosoma with sparse, erect, long, thick and pale setae. Petiole and postpetiole shiny, with sparse and gentle rugosity on the entire surface, thicker sculpture on the dorsal surface. Gaster smooth and shiny, bearing sparse, long, suberect to erect setae.

Type Material
Holotype: Bulgaria: Maleshevska Planina Mts. vic. Gorna Breznitsa, 5 km W Kresna, 8.6.2009, leg. Csősz, N 41.7523, E 23.1106, 350 m a.s.l., collection code: 188, (1 w,, Budapest). Paratypes: Bulgaria: Maleshevska Planina Mts vic. Gorna Breznitsa, 5 km W Kresna,, 08.06.2009, leg. Csősz, N 41.7523, E 23.1106, 350 m a.s.l., collection code: 188, (7 w, 1 q, HNHM, Budapest); Maleshevska Planina Mts. 2 km SW Mikrevo, 9.6.2009, leg. Csősz, N 41.6093, E 23.1806, 350 m a.s.l., collection code: 238, (6 w, HNHM, Budapest; 3 w, 1 q, UWPC, Wroclaw); Maleshevska Planina Mts 2 km SW Mikrevo, 09.06.2009, leg. Csősz, N 41.6093, E 23.1806, 350 m a.s.l., collection code: 239, (5 w, 1 q, HNHM, Budapest).

Etymology
This name refers to the ancient name of Struma River [Strymon]. Its valley is the locus typicus of this species.

References based on Global Ant Biodiversity Informatics

 * Csosz S., S. Salata, and L. Borowiec. 2018. Three Turano-European species of the Temnothorax interruptus group (Hymenoptera: Formicidae) demonstrated by quantitative morphology. Myrmecological News 26: 101-119.
 * Salata S., and L. Borowiec. 2018. Taxonomic and faunistic notes on Greek ants (Hymenoptera: Formicidae). Annals of the Upper Silesian Museum in Bytom Entomology 27: 1-51.
 * Salata S., and L. Borowiec. 2019. Preliminary division of not socially parasitic Greek Temnothorax Mayr, 1861 (Hymenoptera, Formicidae) with a description of three new species. ZooKeys 877: 81-131.