Temnothorax tuberum

Identification
Colour varies from entirely pale yellowish brown with the head pale to almost black and the dorsum of the gaster brownish. The antennal clubs are brown to brownish black contrasting with the rest of the funiculus. The head and clypeus are longitudinally striate and the alitrunk rugose. The petiole node has a distinct but short truncate dorsal area; propodeal spines are very short but quite distinct. Length: 2.3-3.4 mm (Collingwood 1979).

Distribution
A common and very widely distributed species in the mountains of Central Europe from Spain to the Caucasus and North Italy to Central Sweden (Collingwood 1979).

Distribution based on Regional Taxon Lists
Palaearctic Region: Andorra, Armenia, Austria, Belarus, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, France, Georgia, Germany, Hungary, Iberian Peninsula, Iran, Jersey, Kyrgyzstan, Latvia, Lithuania, Luxembourg, Montenegro, Netherlands, Norway, Poland, Portugal, Republic of Korea, Republic of Macedonia, Republic of Moldova, Romania, Russian Federation, Slovakia, Slovenia, Spain, Sweden, Switzerland.

Biology
Collingwood (1979) - This species characteristically nests in small single queened colonies under stones and in rock crevices. In Scandinavia it is restricted to warm lowland habitats. The alatae are found in July and August.

The original and very brief description was based on Swedish material but the types are lost. Most Scandinavian samples have dark heads and could be referred to the supposed species L. nigriceps Mayr, 1855. In England where L. tuberum is locally abundant along the south coast, the colour tends to be uniformly pale but samples also occur with dark heads and there are no structural differences between dark headed and light coloured series.

Fungi
This species is a host for the endoparastic fungus Myrmicinosporidium durum (Espadaler & Santamaria, 2012).

Nomenclature

 *  tuberum. Formica tuberum Fabricius, 1775: 393 (w.) SWEDEN. Lepeletier, 1835: 183 (q.m.); Nylander, 1846a: 939 (q.m.); Adlerz, 1886: 82 (gynandromorph); Hauschteck, 1962: 219 (k.). Combination in Manica: Jurine, 1807: 279; in Leptothorax: Mayr, 1855: 442; in Temnothorax: Bolton, 2003: 271. Senior synonym of tuberosa: Stephens, 1829: 356; Dalla Torre, 1893: 127; of melanocephalus: Casevitz-Weulersse, 1990b: 420; of acutinodis: Arakelian, 1994: 58; of pratostepposus: Radchenko, 1994d: 157 (in key); of alaicus, ciscaucasicus, nigricephalus, stipaceus: Radchenko, 1995c: 14. Material of the nomen nudum nigroscutellata referred here by Emery, 1914e: 2. See also: Baroni Urbani, 1971c: 124; Tarbinsky, 1976: 96; Kutter, 1977c: 134; Collingwood, 1979: 75; Atanassov & Dlussky, 1992: 142; Orledge, 1998: 25. Current subspecies: nominal plus tuberonigriceps.
 * tuberosa. Formica tuberosa Latreille, 1802c: 259 (w.q.) FRANCE. Erroneous rendering and hence junior synonym of tuberum: Stephens, 1829: 356; Dalla Torre, 1893: 127.
 * melanocephalus. Leptothorax melanocephalus Emery, 1870: 197 (w.) FRANCE (Corsica). Subspecies of tuberum: André, 1883a: 298; Forel, 1890a: lxxiv; Emery, 1891b: 5; Santschi, 1919e: 242. Status as species: Bondroit, 1920a: 154; Baroni Urbani, 1971c: 115; Collingwood, 1978: 70; Atanassov & Dlussky, 1992: 138. Junior synonym of tuberum: Casevitz-Weulersse, 1990b: 420.
 * stipaceus. Leptothorax tuberum subsp. stipaceus Ruzsky, 1905b: 586 (w.q.m.) RUSSIA. Raised to species: Ruzsky, 1925b: 45. See also: Arnol'di, 1971: 1825. Junior synonym of tuberum: Radchenko, 1995c: 14.
 * nigricephala. Leptothorax (Leptothorax) tuberum var. nigricephala Karavaiev, 1930b: 146 (w.q.) SWEDEN. [Also described as new by Karavaiev, 1931e: 212.] Junior synonym of tuberum: Radchenko, 1995c: 14.
 * alaicus. Leptothorax tuberum subsp. alaicus Tarbinsky, 1976: 97 (w.) KYRGYZSTAN. Junior synonym of tuberum: Radchenko, 1995c: 14.
 * acutinodis. Leptothorax tuberum subsp. acutinodis Arnol'di, 1977a: 204 (w.) ARMENIA. [Leptothorax tuberum subsp. acutinodis Arnol'di, 1948: 211. Nomen nudum.] Junior synonym of tuberum: Arakelian, 1994: 58; Radchenko, 1995c: 15.
 * ciscaucasicus. Leptothorax tuberum subsp. ciscaucasicus Arnol'di, 1977a: 204 (w.q.) RUSSIA. Junior synonym of tuberum: Radchenko, 1995c: 15.
 * pratostepposus. Leptothorax pratostepposus Arnol'di, 1977a: 202 (w.q.) RUSSIA. Junior synonym of tuberum: Radchenko, 1994d: 157 (in key); Radchenko, 1995c: 14.

'Leptothorax (Leptothorax) tuberum'' F. var. nigricephala''' Karawajew, 1930: 146.

Type locality(-ies): “Gotland (44 Fundorte, 47 Proben): 2, 3, 11, 12, 31, 32, 38, 39, 41, 43, 68, 72, 75, 79, 79*, 80, 81, 91, 103, 107, 108, 111, 192, 193, 194, 206, 207, 217, 218, 220, 221, 221*, 225, 226, 228, 229.

Oeland: (19 Fundorte, 21 Proben): 2,b, 3, 9, 12,c, 15,c, 15,e, 18,a, 18,f, 22, 27,e, 35,d, 35,h, 36,a, 36,c, 41,b, 42,b, 51,c, 52,b, 55, 57,a, 69,c, 80,c” (for details of these localities see Karawajew, 1930, pp. 110–144).

Original Karawajew label(-s): “Leptothorax (Leptothorax) / tuberum F. v. nigricephala Kar. / typus. Gotland, H. Lohmander / leg. Karavaiev dt.”; “Leptothorax (Leptothorax) / tuberum F. v. nigricephala / Kar. typus. Oeland, Loh- / mader leg. Karavaiew det.”.

Material: SYNTYPES, 12 w, 2 q, 1 m (newly mounted, IN 314/6/1), 1078 w, 61 q, 40 m, 12 pupae (in alcohol, IN 314/BAMS1/Karaw62, 64).

Notes. Karawajew (1930, 1931) had investigated abundant material from Sweden (including Islandes Gotland and Öland) collected by H. Lohmander. He had recorded for these territories only three species from the former genus Leptothorax: L. acervorum (F.), L. muscorum (Nyl.), and L. tuberum nigricephala (for the details of the taxonomic history of this genus see Bolton 2003). Thus, any material of var. nigricephala collected by Lohmander in Sweden and preserved in Karawajew’s collection could be considered as syntypes of this taxon.