Temnothorax interruptus

This species occurs mostly in xerothermic grasslands or other open habitats, especially in northern localities, and it can often be collected in overgrown limestone or gypsum rocks. It nests in soil, under stones, in moss or in rock rubble. Sometimes specimens can be found at the edges of dry, deciduous oak forests (Csosz et al., 2018).

Identification
Collingwood (1979) - Light bright yellow with dark areas at the side of the dorsum of the first gaster segment and frequently at the front corners of the head. The antennal club is distinctly dark. The dorsal outline of the alitrunk is smoothly curved without a break and the propodeal spines are long and curved. The petiole node is steeply peaked in profile. Length: 2.3-3.4 mm.

Csosz et al. (2018) - Morphological characteristics of Temnothorax interruptus are considered the most distinct amongst three closely related species. Its workers differ from Temnothorax morea and Temnothorax strymonensis in: 1) shorter antennal scape which never reaches occipital margin of head; 2) wide frontal lobes (FL / SL > 0.5 μm); and 3) low SL / CS ratio (0.800 ± 0.02 in T. interruptus vs. 0.894 ± 0.02 in T. morea vs. 0.856 ± 0.02 in T. strymonensis).

Gynes of Temnothorax interruptus differ from those of T. morea and T. strymonensis in: 1) darker body colour (brown to dark brown vs. orange to bright orange); 2) shorter antennal scape which never reaches occipital margin of head (in T. morea and T. strymonensis antennal scape reaches occipital margin of head); and 3) the whole surface of the scutum is conspicuously costulate (in T. morea and T. strymonensis the dorsal surface of scutum inconspicuously costulate or smooth).

Distribution
This is a Turano-European species. Its known distribution stretches from Spain to the Caucasus, from Central Europe to the Mediterranean peninsula. This species, by crossing the Caucasus, also gained a foothold in Eastern Turkey, where it co-occurs with Temnothorax strymonensis (Csosz et al., 2018).

Distribution based on Regional Taxon Lists
Palaearctic Region: Armenia, Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Denmark, Finland, France, Germany, Hungary, Iberian Peninsula, Montenegro, Netherlands, Norway, Poland, Republic of Macedonia, Romania, Russian Federation, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine , United Kingdom of Great Britain and Northern Ireland.

Biology
Collingwood (1979) - This is a rather uncommon ground nesting species. In Britain where it has been well studied by Donisthorpe (1927) it is found nesting in dry peat or among small stones and heather roots in small colonies of 50-100 workers and single queens. Alatae are present in the nests during July.

Nomenclature

 *  interruptus. Myrmica interrupta Schenck, 1852: 106 (w.q.) GERMANY.
 * [Also described as new by Schenck, 1853: 188.]
 * Mayr, 1855: 446 (m.).
 * Combination in Leptothorax: Mayr, 1855: 446.
 * Combination in Temnothorax: Bolton, 2003: 271.
 * As unavailable (infrasubspecific) name: Lameere, 1892: 69.
 * Subspecies of tuberum: Forel, 1874: 85 (in key); Emery & Forel, 1879: 458; André, 1883a: 299; Emery, 1884a: 379; Forel, 1890a: lxxiv; Emery, 1891b: 6; Emery, in Dalla Torre, 1893: 127 (footnote); Emery, 1898c: 134; Forel, 1904f: 425; Bondroit, 1910: 497; Stitz, 1914: 63; Crawley, 1914a: 91 (in key); Forel, 1915d: 24 (in key); Emery, 1916b: 175; Escherich, 1917: 328 (in key); Bondroit, 1918: 132; Soudek, 1922: 55; Emery, 1924d: 256; Menozzi, 1925d: 29; Finzi, 1930d: 315; Stitz, 1939: 171.
 * Status as species: Mayr, 1855: 446 (redescription); Smith, F. 1858b: 120; Roger, 1859: 258; Mayr, 1861: 59 (in key); Roger, 1863b: 26; Mayr, 1863: 427; André, 1874: 191 (in key); Emery, 1878b: 51; Dalla Torre, 1893: 124; Bondroit, 1911: 12; Donisthorpe, 1915d: 166; Bondroit, 1918: 132; Müller, 1923b: 94; Donisthorpe, 1927b: 185; Lomnicki, 1928: 5; Zimmermann, 1935: 33; Novák & Sadil, 1941: 93 (in key); Novák, in Kratochvíl, et al. 1944: 119; Consani & Zangheri, 1952: 41; Bernard, 1956a: 163; Bernard, 1967: 212 (redescription); Baroni Urbani, 1971c: 109; Pisarski, 1975: 20; van Boven, 1977: 107; Kutter, 1977c: 131; Collingwood, 1978: 84 (in key); Arnol'di & Dlussky, 1978: 542 (in key); Collingwood, 1979: 75; Agosti & Collingwood, 1987b: 275 (in key); Atanassov & Dlussky, 1992: 138; Douwes, 1995: 90; Bolton, 1995b: 239; Czechowski, et al. 2002: 48; Seifert, 2007: 233; Casevitz-Weulersse & Galkowski, 2009: 495; Lapeva-Gjonova, et al. 2010: 22; Boer, 2010: 51; Legakis, 2011: 18; Borowiec, L. & Salata, 2012: 542; Czechowski, et al. 2012: 145; Borowiec, L. 2014: 179; Radchenko, 2016: 232; Csősz et al., 2018: 109.
 * Senior synonym of simpliciuscula: Roger, 1859: 258; Mayr, 1861: 59; Roger, 1863b: 26; Mayr, 1863: 427; André, 1874: 203 (in list); Forel, 1874: 102 (in list); Emery & Forel, 1879: 459; Dalla Torre, 1893: 124, Emery, 1924d: 256; Radchenko, 2016: 232.
 * Senior synonym of tuberoaffinis: Plateaux & Cagniant, 2013: 429.
 * Senior synonym of knipovitshi: Csősz et al., 2018: 109.
 * Senior synonym of junipereti: Csősz et al., 2018: 118.
 * Senior synonym of nikitae: Csősz et al., 2018: 118.
 * junipereti. Leptothorax junipereti Arnol'di, 1977a: 203 (w.) UKRAINE.
 * Status as species: Arnol'di & Dlussky, 1978: 543 (in key).
 * Junior synonym of knipovitshi: Radchenko, 1994d: 156 (in key); Radchenko, 1995c: 18.
 * Junior synonym of interruptus: Csősz et al., 2018: 118.
 * knipovitshi. Leptothorax tuberum subsp. knipovitshi Karavaiev, 1916: 499 (w.q.) UKRAINE.
 * Combination in Temnothorax: Bolton, 2003: 271.
 * Subspecies of tuberum: Karavaiev, 1927c: 266 (in key); Karavaiev, 1934: 139 (redescription).
 * Status as species: Radchenko, 1994d: 156 (in key); Bolton, 1995b: 240; Radchenko, 1995c: 17; Borowiec, L. 2014: 180; Radchenko, 2016: 222.
 * Junior synonym of interruptus: Csősz et al., 2018: 109.
 * Senior synonym of junipereti: Radchenko, 1994d: 156 (in key); Radchenko, 1995c: 18; Radchenko, 2016: 222.
 * Senior synonym of nikitae: Radchenko, 1994d: 156 (in key); Radchenko, 1995c: 18; Radchenko, 2016: 222.
 * nikitae. Leptothorax nikitae Arnol'di, 1977a: 202 (w.) UKRAINE.
 * Status as species: Arnol'di & Dlussky, 1978: 543 (in key); Arakelian, 1994: 55.
 * Junior synonym of knipovitshi: Radchenko, 1994d: 156 (in key); Radchenko, 1995c: 18.
 * Junior synonym of interruptus: Csősz et al., 2018: 118.
 * simpliciuscula. Myrmica simpliciuscula Nylander, 1856b: 92, pl. 3, fig. 40 (w.) FRANCE.
 * Status as species: Smith, F. 1858b: 120.
 * Junior synonym of interruptus: Roger, 1859: 258; Mayr, 1861: 59.
 * tuberoaffinis. Leptothorax tuberoaffinis Bondroit, 1918: 131 (w.q.) SWITZERLAND.
 * [First available use of Leptothorax tuberum r. affinis var. tuberoaffinis Forel, 1915d: 23 (in key) (w.q.) SWITZERLAND; unavailable (infrasubspecific) name.]
 * [Leptothorax tuberum var. tuberoaffinis Forel, 1874: 86; Dalla Torre, 1893: 128. Nomina nuda.]
 * Subspecies of affinis: Stitz, 1939: 174; Novák & Sadil, 1941: 92 (in key); Bolton, 1995b: 246 (error).
 * Junior synonym of affinis: Kutter, 1977c: 14; Radchenko, 2016: 217 (error).
 * Junior synonym of interruptus: Plateaux & Cagniant, 2013: 428.

Worker
Head orange to dark orange with brown to dark 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 darker brown to dark brown. Mesosoma, legs, petiole and postpetiole orange to dark orange. Sometimes femora darker. Gaster orange to dark orange with complete brown to brownish-black, transverse band on the apical part of the first tergite. In most specimens the band is broad, occupies apical ⅓ to ½ length of first tergite, its anterior margin straight or on sides only slightly protruding forward. In rare aberrations first tergite with transverse band narrower than ⅓ length of the tergite, narrowly interrupted along the middle and laterally distinctly protruding forward.

Head quadratic (CL / CWb: 1.228 [1.161, 1.276]). Eyes small, oval, (EL / CS: 0.259 [0.231, 0.278]). Antennal scape short (SL / CS: 0.80 [0.748, 0.843]), not reaching occipital margin of head. Surface of the scape with very fine microsculpture, shiny, covered with short, moderately dense, suberect or adpressed setae. Mesosoma elongate (ML / CS: 1.223 [1.167, 1.303]), dorsal contour line in profile slightly rounded. Propodeal spines long (SPST / CS: 0.356 [0.314, 0.392]), wide at base, curved downwards with pointed apex. Frontal carinae short, extending to ⅓ length of eye; antennal fossa shallow, rugulose with costae. Frontal lobes distinctly wider than frons (FL / FR: 1.168 [1.111, 1.236]), and shiny. Frons longitudinally costate and sometimes rugose, interstices shiny. Postocular area of head rugulose, sometimes longitudinally costulate. Genae sometimes with sparser rugosity. Interstices feebly microreticulate, shiny. Entire head bearing suberect to erect, pale and thin setae.

Dorsum of mesosoma densely rugose. Lateral surface of promesonotum longitudinally costulate. Lateral surface of propodeum rugulose. Interstices shiny with microreticulation or micropunctation. Area between and below propodeal spines shiny and punctate. Dorsal surface of mesosoma with sparse, erect, long, thick and pale setae. Petiole punctate to rugulose, interstices shiny.

Queen
Head dark brown, sometimes temples orange. Antennal club brown to bright brown. Mesosoma, petiole and postpetiole dark brown to brown, sometimes with brighter spots on the pronotum. Legs orange. First gastral tergite mostly brown with orange spot basally but apical margin always pale, remaining tergites yellow-orange basally and brown apically but the light goes dark gradually.

Eyes big, oval [EL / CS: 0.34 ± 0.004]. Antennal scape short [SL / CS: 0.76 ± 0.03], not reaching occipital margin of head. Propodeal spines medium length [SPST / CS: 0.38 ± 0.01], wide at base, triangular, straight, with acute apex. Clypeus shiny with diffuse, longitudinally carinulae, interstices smooth. Antennal fossa deep, rugulose with concentric carinae. Frontal lobes wide [FLS / CS: 0.46 ± 0.01], rugulose with thick longitudinal costae, interstices shiny. Frons shiny, entire surface longitudinally costate and rugose, interstices smooth and shiny. Area above eyes and sides of head rugulose and sometimes longitudinally costate, interstices shiny. Entire head bearing suberect to erect, pale and thin setae.

Pronotum with thick rugosity on whole dorsal surface. Sides with thick rugosity or gentle, dense longitudinal costae. Surface between rugosity smooth and shiny. Scutum with dense, thick longitudinal costae, shiny. Sometimes rugosity weaker laterally. Scutellum smooth and shiny at the centre, sides smooth or with diffuse, thick, longitudinal costae. Metanotum with slight sculpture, rugulose or punctate. Sometimes with a few thick wrinkles. Propodeum with variable sculpture. Area above propodeal spines with very sparse, transverse and gentle costae or sparse irregular rugosity, interstices microreticulate, shiny. Area between and below propodeal spines with dense punctation. Sides of propodeum punctate or with slight, dense rugosity. Sometimes with a few longitudinal costae, always shiny. Anepisternum and katepisternum shiny, with gentle, dense longitudinal costae. Metaepisternum and metakatepisternum, shiny, with dense, longitudinal rugosity. Surface between rugosity punctate. Dorsal surface of mesosoma with sparse, erect, long, thick and pale setae. Petiole and postpetiole shiny, the entire surface punctate to rugulose, dorsal surface longitudinally costulate. Gaster smooth and shiny, bearing sparse, long, suberect to erect setae.

Type Material
Types studied by Salata et al. (2018): Temnothorax interruptus: Syntype (w.) (FOCOL2008): [Nassau | Leptothorax interruptus Schenck || interruptus Schenck || Type || GBIF-D/FoCol 2010 | specimen + label | data documented] (ZMHB).