Leptothorax muscorum

This species shows a preference for drier and warmer habitats (it does not inhabit bogs). In the mountains, it lives in meadows. Nests are built under small stones, under bark, in rotten wood, sometimes in litter. (Radchenko 2004)

Identification
Pale brown to brown with antennal clubs and head often slightly darker. Propodeal spines short but distinct. General appearance more slender than Leptothorax acervorum. Head striate, mesosoma rugose and gaster smooth. Appendage hairs few and adpressed. Clypeus in some Scandinavian series have a distinct median concavity as described for Leptothorax gredleri Mayr (Buschinger, 1966) but they are not otherwise different from the typical species. Length: 2.4-3.2 mm (Collingwood 1979).

Distribution
Appenines to Central Scandinavia and Pyrenees to Urals, not found in British Isles but common in continental Europe (Collingwood 1979).

Distribution based on Regional Taxon Lists
Palaearctic Region: Andorra, Armenia, Austria, Belarus, Belgium, Bulgaria, China, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, Iberian Peninsula, Kyrgyzstan, Latvia, Liechtenstein, Lithuania, Luxembourg, Mongolia, Montenegro, Netherlands, Norway, Poland, Republic of Moldova, Romania, Russian Federation, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine.

Biology
In Scandinavia, this species is restricted to sheltered valleys in woodland areas where it nests in stony banks, tree stumps or under bark. Its habits are similar to those of L. acervorum with small colonies having one or occasionally two queens. Males and alate queens are found in July and August.

This species is a host for the slave-making species.

Nomenclature

 *  muscorum. Myrmica muscorum Nylander, 1846b: 1054 (w.q.m.) FINLAND.
 * Combination in Leptothorax: Mayr, 1855: 439.
 * Combination in L. (Mychothorax): Ruzsky, 1904a: 288.
 * Subspecies of acervorum: Forel, 1874: 84 (in key); Emery & Forel, 1879: 458; Ruzsky, 1896: 72; Escherich, 1917: 328 (in key); Soudek, 1922: 50.
 * Status as species: Foerster, 1850a: 59; Mayr, 1855: 439 (redescription); Nylander, 1856b: 90; Smith, F. 1858b: 118; Mayr, 1861: 58 (in key); Roger, 1863b: 26; Mayr, 1863: 427; André, 1874: 189 (in key); André, 1883a: 294 (in key); Nasonov, 1889: 31; Dalla Torre, 1893: 125; Emery, 1895c: 318; Wheeler, W.M. 1901b: 519; Ruzsky, 1902d: 21; Ruzsky, 1903c: 207; Ruzsky, 1905b: 616; Wasmann, 1906: 119 (in key); Bondroit, 1910: 497; Karavaiev, 1912b: 582; Stitz, 1914: 62; Forel, 1915d: 26 (in key); Karavaiev, 1916: 503; Wheeler, W.M. 1917a: 511; Bondroit, 1918: 121; Bondroit, 1920a: 153; Müller, 1923b: 88 (in key); Emery, 1924d: 262; Menozzi, 1925d: 33; Lomnicki, 1928: 5; Karavaiev, 1931e: 212; Karavaiev, 1934: 145 (redescription); Novák & Sadil, 1941: 89 (in key); Novák, in Kratochvíl, Novák & Šnoflák, 1944: 112; Röszler, 1950: 225; Brown, 1955a: 47; Bernard, 1956a: 161; Buschinger, 1966b: 165; Francoeur & Béique, 1966: 142; Bernard, 1967: 200 (redescription); Pisarski, 1969a: 229; Pisarski, 1969b: 297; Dlussky & Pisarski, 1970: 86; Baroni Urbani, 1971c: 99; Pisarski, 1975: 23; Aktaç, 1977: 122; van Boven, 1977: 101; Kutter, 1977c: 130; Collingwood, 1978: 83 (in key); Arnol'di & Dlussky, 1978: 543 (in key); Wheeler, G.C. & Wheeler, J. 1978: 391; Collingwood, 1979: 72; Smith, D.R. 1979: 1397; Pisarski & Krzysztofiak, 1981: 157; Espadaler & Collingwood, 1982: 41; Allred, 1982: 484; Kupyanskaya, 1986b: 96; Wheeler, G.C. & Wheeler, J. 1986g: 53; Agosti & Collingwood, 1987b: 273 (in key); Nilsson & Douwes, 1987: 60; Loiselle, et al. 1990: 323; Kupyanskaya, 1990: 139; Atanassov & Dlussky, 1992: 132; Arakelian, 1994: 55; Radchenko, 1994b: 111 (in key); Radchenko, 1994d: 147 (in key); Douwes, 1995: 89; Bolton, 1995b: 241; Radchenko, 1995a: 25; Czechowski, et al. 2002: 42; Mackay & Mackay, 2002: 129; Radchenko, 2004: 130; Coovert, 2005: 79; Seifert, 2007: 225; Radchenko, 2007: 31; Zryanin & Zryanina, 2007: 231; Casevitz-Weulersse & Galkowski, 2009: 488; Lapeva-Gjonova, et al. 2010: 20; Boer, 2010: 50; Legakis, 2011: 16; Borowiec, L. & Salata, 2012: 510; Czechowski, et al. 2012: 132; Borowiec, L. 2014: 99; Radchenko, 2016: 210; Schar et al., 2018: 6.
 * Senior synonym of betulae: Radchenko, 1995a: 25; Radchenko, 2016: 210.
 * Senior synonym of fagi: Radchenko, 1995a: 25; Radchenko, 2016: 210.
 * Senior synonym of flavescens: Radchenko, 1995a: 25; Radchenko, 2016: 210.
 * Material of the unavailable name “uvicensis” referred here.
 * flavescens. Leptothorax muscorum var. flavescens Ruzsky, 1896: 72 (w.) RUSSIA. [First available use of Leptothorax acervorum subsp. muscorum var. flavescens Ruzsky, 1895: 26; unavailable name.] Subspecies of muscorum: Ruzsky, 1905b: 621. Junior synonym of muscorum: Radchenko, 1995a: 25.
 * betulae. Leptothorax muscorum var. betulae Ruzsky, 1916: 6 (w.) RUSSIA. Subspecies of muscorum: Ruzsky, 1936: 94. Junior synonym of muscorum: Radchenko, 1995a: 25.
 * fagi. Leptothorax (Mychothorax) muscorum var. fagi Ruzsky, 1905b: 619, fig. 151 (w.) CAUCASUS. Junior synonym of muscorum: Radchenko, 1995a: 25.