Temnothorax parvulus

Identification
Csösz et al. (2015) - A member of the parvulus species-complex. Temnothorax parvulus can be separated easily from members of other species-complexes by its homogenously areolate microsculpture on the head dorsum. The head sculpture of other species complexes may vary from smooth to coarsely rugulo-reticulate but is never homogenously areolate. In exceptional cases, long-spined species of the Temnothorax lichtensteini complex might exhibit a homogenous areolate sculpture on an extended area of the head dorsum, but T. parvulus is distinguished from T. lichtensteini and Temnothorax laconicus by its more erect propodeal spines (38–42° vs. ca. 20–25°). Temnothorax parvulus can also be safely separated from weakly sculptured, lightly colored Temnothorax tergestinus samples using slightly overlapping NOH/CS, SPTI/CS and SPWI/CS ratios (see S4 Table).

Temnothorax parvulus shares most its surface sculpture characters with other species belonging to this complex, Temnothorax ariadnae and Temnothorax helenae. Spine length ratio (SPST/CL) helps distinguish Temnothorax parvulus from T. ariadnae and T. helenae.

Non-overlapping values of SPST/CL for nest sample means of T. parvulus (mean: 0.282 [min: 0.259, max: 0.303]); and T. ariadnae (mean: 0.216 [min: 0199, max: 0.227]) provide a prefect means of separation. As 5% of nest samples of T. parvulus and T. helenae (mean: 0.234 [min: 0.189, max: 0.274] overlap in this ratio, the safest determination is provided by a discriminant (D5 = 0.0393_CL -0.0616_SPST +0.0892_PEW -0.0580_PPW -0.0338_SPWI -8.7356) formula, which separates 97.1% of single individuals and all nest samples of T. parvulus and T. helenae.

Distribution
Western Europe to the Black see coast and Turkey and from Italy and the Balkans to Central Europe.

Distribution based on Regional Taxon Lists
Palaearctic Region: Andorra, Armenia, Austria, Belgium, Bulgaria, Croatia, Czech Republic, Georgia, Germany, Gibraltar, Greece, Hungary, Iberian Peninsula, Iran, Italy, Montenegro, Poland, Portugal, Republic of Macedonia, Republic of Moldova, Romania, Russian Federation, Slovakia, Slovenia, Spain, Turkey, Turkmenistan.

Nomenclature

 *  parvulus. Myrmica parvula Schenck, 1852: 103 (w.) GERMANY.
 * [Also described as new by Schenck, 1853: 187.]
 * Mayr, 1855: 448 (q.); Novák, in Kratochvíl, Novák & Šnoflák, 1944: 116 (m.).
 * Combination in Leptothorax: Mayr, 1855: 448.
 * Combination in Temnothorax: Bolton, 2003: 271.
 * Junior synonym of cingulata: Nylander, 1856b: 93.
 * Junior synonym of nylanderi: Smith, F. 1858b: 8; Roger, 1863b: 26.
 * Subspecies of tuberum: André, 1883a: 300.
 * Subspecies of nylanderi: Forel, 1874: 86; Dalla Torre, 1893: 126; Ruzsky, 1902d: 23; Stitz, 1914: 64; Forel, 1915d: 22 (in key); Emery, 1916b: 175; Menozzi, 1918: 85; Bondroit, 1918: 123; Menozzi, 1918: 85; Müller, 1923b: 95; Emery, 1924d: 255; Novák & Sadil, 1941: 91 (in key).
 * Status as species: Mayr, 1855: 448; Bernard, 1956a: 161; Bernard, 1959: 349; Bernard, 1967: 203 (redescription); Baroni Urbani, 1971c: 119; van Boven, 1977: 105; Arnol'di & Dlussky, 1978: 541 (in key); Agosti & Collingwood, 1987b: 274 (in key); Dlussky, Soyunov & Zabelin, 1990: 191; Casevitz-Weulersse, 1990c: 418 (in key); Atanassov & Dlussky, 1992: 140; Arakelian, 1994: 56; Radchenko, 1994d: 153 (in key); Bolton, 1995b: 242; Radchenko, 1995d: 4; Czechowski, et al. 2002: 52; Seifert, 2007: 241; Boer, 2010: 52; Czechowski, et al. 2012: 150; Csösz, Heinze & Mikó, 2015: 47 (redescription).

Worker
Csösz et al. (2015) - 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: 488–586 μm (mean = 550, n = 29). Cephalic length vs. Maximum width of head capsule (CL/CWb): 1.147–1.214 (mean = 1.184). Postocular distance vs. cephalic length (PoOc/CL): 0.392–0.413 (mean = 0.405). Postocular sides of cranium contour frontal view orientation: converging posteriorly. Postocular sides of cranium contour frontal view shape: strongly 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: 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): 0.237–0.262 (mean = 0.250). Frontal carina distance vs. absolute cephalic size (FRS/CS): 0.353–0.376 (mean = 0.361). Longitudinal carinae on median region of frons count: absent. Smooth median region on frons count: present. Antennomere count: 12. Scape length vs. absolute cephalic size (SL/CS): 0.763–0.796 (mean = 0.778). 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: 38–42°. Spine length vs. absolute cephalic size (SPST/CS): 0.278–0.331 (mean = 0.306). Minimum spine distance vs. absolute cephalic size (SPBA/CS): 0.273–0.312 (mean = 0.292). Maximum spine distance vs. absolute cephalic size (SPWI/CS): 0.353–0.415 (mean = 0.384). Apical spine distance vs. absolute cephalic size (SPTI/CS): 0.332–0.395 (mean = 0.364). Maximum mesosoma width vs. absolute cephalic size (MW/CS): 0.599–0.636 (mean = 0.618). 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: 105–110°. Anterodorsal rim of petiole count: absent medially.

Dorsal profile of petiolar node contour line in lateral view shape: slightly convex. 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
Csösz et al. (2015) - Lectotype: “L. parvulus # Sch” and “Lectotype Leptothorax parvulus Schenck, 1852 det. A. Schulz &M. Verhaagh 1999” (1# / SMF), [GER:parvulus-TYPE].