Temnothorax helenae

On Crete this species inhabits oak forests. Nests are in litter or galls. Workers have been collected in litter or on rocks. Colonies are monogamous (Salata, Borowiec & Trichas, 2018). It prefers forest habitats, especially coniferous forests but was observed also in deciduous and mixed forests and pastures with oak trees and stones. Nests were located in cracked rocks and stones or under moss (Borowiec & Salata, 2021).

Identification
Csösz et al. (2015) - A member of the parvulus species-complex. Temnothorax helenae shares characters with Temnothorax ariadnae and Temnothorax parvulus, differential diagnoses between these species are given under these taxa. Separation of T. helenae from Temnothorax crasecundus can be difficult if only sculpture and shape characteristics are considered, but a single ratio (PoOC/NOH) yields >95% classification success for nest sample means. Several slightly overlapping morphometric traits (CL/CWb, ML/CS, NOH/CS, SL/CS) may provide further options for determination.

The geographical distribution of T. helenae overlaps with those of Temnothorax lucidus and Temnothorax subtilis in a narrow zone in Greek mainland and in Crete. Temnothorax helenae can be separated easily from the latter two species by the coarser sculpture on its head dorsum and the lack of a sharp antero-lateral ridge on its petiolar node of T. helenae. Both T. lucidus and T. subtilis have a shiny head dorsum and a sharp to moderately sharp antero-lateral ridge on the petiolar node. Due to the fact that head dorsum of T. helenae is occasionally moderately shiny and the antero-lateral rim on the petiolar node may occasionally be inconspicuous in both T. lucidus and T. subtilis, in a few cases determination might be doubtful. A discriminant (D5 = -0.0730_SPST +0.0255_SL -0.0634_POC +0.0405_ML -0.0613_SPBA -4.8074) function yields 97% classification success for individuals and 100% for nest sample means.

Distribution
This species mostly occurs in Greek mainland, but a few localities are also known in Southern Bulgaria, Western Turkey and Crete.

Distribution based on Regional Taxon Lists
Palaearctic Region: Bulgaria, Greece, Turkey.

Nomenclature

 *  helenae. Temnothorax helenae Csösz, Heinze & Mikó, 2015: 45, figs. 26A-C (w.) GREECE.

Worker
Body color: brown; yellow. Body color pattern: mesosoma, antenna and legs, waist and anterior region of 1st gastral tergite lighter than head dorsum and posterior region of gaster. Antenna color pattern: clava concolorous funicle. Absolute cephalic size: 510–627 μm (mean = 566, n = 53). Cephalic length vs. Maximum width of head capsule (CL/CWb): 1.152–1.242 (mean = 1.197). Postocular distance vs. cephalic length (PoOc/CL): 0.384–0.424 (mean = 0.400). Postocular sides of cranium contour frontal view orientation: converging posteriorly. Postocular sides of cranium contour frontal view shape: feebly convex. Vertex contour line in frontal view shape: straight. Vertex sculpture: main sculpture absent, ground sculpture areolate; main sculpture dispersed forked costate sculpture, ground sculpture areolate. Genae contour from anterior view orientation: converging. Gena contour line in frontal view shape: feebly convex. Gena sculpture: rugoso-reticulate with areolate ground sculpture. Median region of antennal rim vs. frontal carina in frontal view structure: not fully overlapped by frontal carina. Concentric carinae laterally surrounding antennal foramen count: present. Eye length vs. absolute cephalic size (EL/CS): 0.238–0.270 (mean = 0.251). Frontal carina distance vs. absolute cephalic size (FRS/CS): 0.335–0.373 (mean = 0.357). Longitudinal carinae on median region of frons count: absent; present. Longitudinal carinae on medial region of frons shape: forked. Smooth median region on frons count: present; absent. Antennomere count: 12. Scape length vs. absolute cephalic size (SL/CS): 0.758–0.808 (mean = 0.783). Facial area of the scape absolute setal angle: 0–15°. External area of the scape absolute setal angle: 30°. Ground sculpture of submedian area of clypeus: smooth. Median carina of clypeus count: present. Lateral carinae of clypeus count: present. Median anatomical line of propodeal spine angle value to Weber length in lateral view: 45–50°. Spine length vs. absolute cephalic size (SPST/CS): 0.205–0.299 (mean = 0.255). Minimum spine distance vs. absolute cephalic size (SPBA/CS): 0.255–0.319 (mean = 0.281). Maximum spine distance vs. absolute cephalic size (SPWI/CS): 0.290–0.387 (mean = 0.334). Apical spine distance vs. absolute cephalic size (SPTI/CS): 0.277–0.370 (mean = 0.320). Maximum mesosoma width vs. absolute cephalic size (MW/CS): 0.580–0.634 (mean = 0.611). Metanotal depression count: present. Metanotal depression shape: shallow. Dorsal region of mesosoma sculpture: rugulose with areolate ground sculpture. Lateral region of pronotum sculpture: areolate ground sculpture, main sculpture forked costate. Mesopleuron sculpture: areolate ground sculpture superimposed by dispersed rugulae. Metapleuron sculpture: areolate ground sculpture superimposed by dispersed rugulae. Frontal profile of petiolar node contour line in lateral view shape: concave. Dorsal profile of petiolar node contour line angle value to frontal profile of petiole contour line in lateral view: 100–110°. Anterodorsal rim of petiole count: absent medially. Dorsal profile of petiolar node contour line in lateral view shape: slightly convex to conspicuously rounded. Dorsal region of petiole sculpture: ground sculpture areolate, main sculpture dispersed rugose; ground sculpture areolate, main sculpture absent. Dorso-caudal petiolar profile contour line in lateral view shape: straight; concave. Dorsal region of postpetiole sculpture: ground sculpture areolate, main sculpture dispersed rugose; ground sculpture areolate, main sculpture absent.

Type Material
Holotype: GRE:344 Greece, Peloponnesus, Taygetos Oros, Street to Profitis Elias, 36.968 N, 22.404 E, 800mH, 01.05.2011, leg. A. Schulz, (, CASENT0914697), [GRE:Taigetos-Oros-20110501-344]; Paratypes: GRE:344 Greece, Peloponnesus, Taygetos Oros, Street to Profitis Elias, 36.968 N, 22.404 E, 800mH, 01.05.2011, leg. A. Schulz, (6## HNHM), [GRE:Taigetos-Oros-20110501-344]; GRE:267 Greece, Peloponnesus, Taygetos Oros, Trail to Profitis Elias, 36.960 N, 22.396 E, 1000-1200mH, 30.04.2011, leg. A. Schulz, (3## HNHM, 2## ), [GRE:Taigetos-Oros-20110430-267]; GRE:280 Greece, Peloponnesus, Taygetos Oros, Trail to Profitis Elias, 36.960 N, 22.396 E, 1000-1200mH, 30.04.2011, leg. A. Schulz, (5## HNHM), [GRE:Taigetos-Oros-20110430-280]; GRE:287 Greece, Peloponnesus, Taygetos Oros, Trail to Profitis Elias, 36.948 N, 22.377 E, 1400-1600mH, 30.04.2011, leg. A. Schulz, (2## HNHM, 2## CAS), [GRE:Taigetos-Oros-20110430-287]; GRE:348 Greece, Peloponnesus, Taygetos Oros, Street to Profitis Elias, 36.968 N, 22.404 E, 800mH, 01.05.2011, leg. A. Schulz, (5## HNHM, 2## CAS), [GRE: Taigetos-Oros-20110501-348]; GRE:350 Greece, Peloponnesus, Taygetos Oros, Street to Profitis Elias, 36.968 N, 22.404 E, 800mH, 01.05.2011, leg. A. Schulz, (5## HNHM), [GRE:Taigetos- Oros-20110501-350].

Etymology
This species is named after Helena, a figure of the Greek mythology.

References based on Global Ant Biodiversity Informatics

 * Borowiec L., and S. Salata. 2017. Ants of the Peloponnese, Greece (Hymenoptera: Formicidae). Polish Journal of Entomology 86: 193-236.
 * Bracko G., K. Kiran, C. Karaman, S. Salata, and L. Borowiec. 2016. Survey of the ants (Hymenoptera: Formicidae) of the Greek Thrace. Biodiversity Data Journal 4: e7945. doi: 10.3897/BDJ.4.e7945
 * Csősz S, Heinze J, and I. Mikó. 2015. Taxonomic synopsis of the Ponto-Mediterranean ants of Temnothorax nylanderi species-group. PLoS ONE 10(11): e0140000. doi:10.1371/journal.pone.0140000
 * Salata S., L. Borowiec, and A.Trichas. 2018. Taxonomic Revision of the Cretan Fauna of the Genus Temnothorax Mayr, 1861 (Hymenoptera: Formicidae), with Notes on the Endemism of Ant Fauna of Crete. Annales Zoologici (Warsaw) 68(4): 769-808.
 * 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.