Tetramorium staerckei

Soil nests often under stones, sometimes covered with grass; small soil mounds exist.

This is a widely distributed species, but its status was clarified only recently (Wagner et al. 2017) thus it remains to be recorded from many countries. Verified records are from Austria, Bulgaria, Czech Republic, Hungary, Kyrgyzstan, Republic of Macedonia, Romania, SW Russia, Serbia, Slovakia and Turkey. The only Greek record is from Lesbos of the Aegean Islands (Borowiec et al., 2022).

Identification
A member of the Tetramorium caespitum complex. The species can be determined with a discriminant analysis of a set of morphological measurements. See Wagner et al. (2017) and https://webapp.uibk.ac.at/ecology/tetramorium/

Distribution
Wagner et al. (2017) - Pannonian zone, Balkans, southern Russia, Central Asia.

Distribution based on Regional Taxon Lists
Palaearctic Region: Austria, Bulgaria, Czech Republic, Hungary, Kyrgyzstan, North Macedonia, Romania, Russian Federation, Serbia, Slovakia, Turkey.

Biology
Wagner et al. (2017) - Thermophilic, different from all species except Tetramorium breviscapus. Avoids editerranean areas, but occurs on Black Sea coast. Typical European habitats are semi-dry and dry grasslands, semi-arid pastures, road embankments, fallow vineyard, rock heaps, sand dunes; exceptionally urban areas. Might be more salt-tolerant than other species, as it was mentioned under "Tetramorium cf. caespitum" as most frequent ant species in saline field in Ocna Sibiului (Romania) (Tausan & Marko 2011; material determined by us). In Kyrgyzstan in meadows, steppes, semideserts, groves.

Adult sexuals in nests on 13 June ± 10 d [1 June, 27 June] (n = 6).

Nomenclature

 *  staerckei. Tetramorium staerckei Kratochvíl, in Kratochvíl, et al. 1944: 65.
 * [First available use of Tetramorium caespitum subsp. hungarica var. staerckei Röszler, 1936b: 60 (w.q.m.) HUNGARY; unavailable (infrasubspecific) name.]
 * Junior synonym of impurum: Kutter, 1977c: 159; Radchenko, 2016: 246.
 * Status as species: Wagner, et al. 2017: 119 (redescription).

Worker
Wagner et al. (2017) - lectotype in μm: CL = 871, CW = 849, dAN = 266, EL = 181, EW = 133, FL = 350, HFL = 739, ML = 1072, MPPL = 322, MPSP = 396, MPST = 238, MW = 581, PEH = 321, PEL = 203, PEW = 303, PLSP = 201, PLST = 239, PnHL = 241, PoOc = 329, POTCos = 10, PPH = 359, PPL = 126, PPW = 378, PreOc = 212, RTI = 347, SLd = 692, SPST = 186, SPWI = 277.

Rather large compared with other species of complex, CS = 746 ± 57 [655, 878] μm. Dark brown to blackish.

Most elongate head of complex, CL / CW = 1.032 ± 0.014 [1.003, 1.062]. Eye rather large, EYE / CS = 0.178 ± 0.005 [0.168, 0.189]. Longest scape of complex, SLd / CS = 0.787 ± 0.016 [0.750, 0.817]. Mesosoma longest within complex and wide, ML / CS = 1.188 ± 0.025 [1.141, 1.247], MW / CS = 0.645 ± 0.014 [0.614, 0.681].

Promesonotal dorsum convex, metanotal groove shallow. – Head dorsum and occiput with longitudinal costae and costulae. Postoculo-temporal area of head with many costae and costulae, POTCos = 10.53 ± 1.75 [7.38, 13.75]. Mesosoma dorsum longitudinally rugulose, lateral side of propodeum with strongest sculpture of complex, Ppss = 16.9 ± 5.3 [11.3, 33.1]. – Dorsum of petiolar with sculpture or smooth. General surface appearance on average dull compared with other species. – Connected stickman-like or reticulate microsculpture: moderate-sized units scattered over 1st gastral tergite, MC1TG = 15.93 ± 2.35 [11.00, 22.00]. – Some workers with long c-shaped, crinkly, or sinuous hairs on ventral head posterior to buccal cavity.

Male
Wagner et al. (2017) - Paramere structure belongs to impurum-like form: rounded ventral paramere lobe without any sharp corner in dorsal or ventral view but with clear division of ventral and dorsal paramere lobes, visible by deep emargination between lobes in posterior view. No sharp corner at end of ventral lobe visible in posterior view. Relatively short dorsal paramere lobe, visible in posterior and dorsal view. Paramere structure length in lateral view > 1014 μm. In dorsal and posterior view, distinct corner on ventral paramere lobe between lobe top and emargination with dorsal lobe.

Type Material
Wagner et al. (2017) - Nagytétény (Hungary), 47.391° N, 18.987° E, 102 m a.s.l., leg. P. Röszler, 17.VI.1935.

Worker closer to needle (of two syntype workers of one card), labeled "Hongrie Nagytétény Coll: Röszler [/] "17. VI. 1935" [–] "500" [–] Typus [–] "Tetramorium caespitum v. hungaricum v. Staerckei worker Rößl. Typus! No. 500" [/] "PAUL RÖSZLER Baross Gabor-telep HONGRIE – EUROPE", designated as lectotype (Fig. 18). Lectotype worker, one paralectotype worker, one paralectotype gyne, and one paralectotype male in Museum of Natural History, Sibiu / Hermannstadt (Romania).

References based on Global Ant Biodiversity Informatics

 * 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. Comments to distribution of several Greek Tetramorium Mayr, 1855 species (Hymenoptera: Formicidae). Annals of the Upper Silesian Museum in Bytom Entomology 28(2): 1-9.
 * Schar S., G Talavera, X. Espadaler, J. D. Rana, A. A. Andersen, S. P. Cover, and R. Vila. 2018. Do Holarctic ant species exist? Trans-Beringian dispersal and homoplasy in the Formicidae. Journal of Biogeography 00: 1-12.
 * Wagner H. C., W. Arthofer, B. Seifert, C. Muster, F. M. Steiner, and B. C. Schlick-Steiner. 2017. Light at the end of the tunnel: Integrative taxonomy delimits cryptic species in the Tetramorium caespitum complex (Hymenoptera: Formicidae). Myrmecological News 25: 95-129.