| Formicoxenus nitidulus|
|At a Glance||• Xenobiotic • Ergatoid queen|
Reddish yellow to brown: whole surface of body smooth and shining with scattered acute pale hairs. Antennal club 3 segmented as long as rest of funiculus: propodeal spines short, set horizontally. Length: 2.8-3.4 mm (Collingwood 1979).
Spain to Eastern Siberia. North Italy to latitude 70º N (Collingwood 1979).
Distribution based on Regional Taxon Lists
Palaearctic Region: Austria, Belarus, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland (type locality), France, Germany, Greece, Hungary, Iberian Peninsula, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Norway, Poland, Republic of Moldova, Romania, Russian Federation, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom of Great Britain and Northern Ireland.
Distribution based on specimens
Collingwood (1979) - This ant occurs only in the nests of Formica rufa and allied mound building species. It is ignored by its host among which the inquiline species moves freely. Individual nests contain only a few individuals, up to about 100, but often several nests are present within one mound of the host. Nests are located in fragments of wood, hollow twigs, bases of old bracken stems and in the earth floor of the Formica mound. Individuals normally remain concealed within the nests but may wander on the mound surface on warm dull days. It is not known to feed on the Formica brood but in captivity will destroy Leptothorax larvae. Males and winged females may be found during July and August. Mating occurring on the surface of the Formica mound. Ergatoid queens (i.e. wingless at emergence) are frequent. Mated egg-layers include dealate queens and ergatoid queens. Workers and sexuals are able to solicit food from wood ants, either directly, or the guest ant climbs up the legs and thorax to the head of a host ant that is engaged in food exchange with another Formica, then steals a little food from the droplet the two ants have between their mandibles.
Francoeur et al. (1985) described ergatoid queens to have 1-3 ocelli and other traits resembling more or less the winged queens
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- nitidulus. Myrmica nitidula Nylander, 1846b: 1058 (w.) FINLAND. Nylander, 1849: 34 (q.); Mayr, 1855: 419 (m.). Combination in Formicoxenus: Mayr, 1855: 418. Senior synonym of laeviuscula: Mayr, 1855: 418; of picea: Francoeur, Loiselle & Buschinger, 1985: 380. See also: Kutter, 1977c: 144; Francoeur, Loiselle & Buschinger, 1985: 380; Radchenko, 2007: 32.
- laeviuscula. Myrmica laeviuscula Foerster, 1850a: 54 (q.) GERMANY. Junior synonym of nitidulus: Mayr, 1855: 418.
- picea. Leptothorax nitidulus var. picea Wasmann, 1906: 120 (w.) LUXEMBOURG. Junior synonym of nitidulus: Francoeur, Loiselle & Buschinger, 1985: 380.
- Adlerz, G. 1885 ("1884"). Myrmecologiska studier. I. Formicoxenus nitidulus Nyl. Öfversigt af Kongliga Vetenskaps-Akademiens Förhandlingar. Stockholm 41(8):43-64. 
- Buschinger, A. (2009) Social parasitism among ants: a review. (Hymenoptera: Formicidae). Myrmecological News 12: 219-235.
- Collingwood, C. A. 1979. The Formicidae (Hymenoptera) of Fennoscandia and Denmark. Fauna Entomol. Scand. 8:1-174.
- Czechowski, W.; Czechowska, W. 1999a. New sites in Poland and notes on the biology of socially parasitic ants Formicoxenus nitidulus (Nyl.) and Harpagoxenus sublaevis (Nyl.) (Hymenoptera, Formicidae). Fragm. Faun. (Warsaw) 42: 1-6 (page 1, record in Poland)
- Donisthorpe, H. 1915f. British ants, their life-history and classification. Plymouth: Brendon & Son Ltd., xv + 379 pp. (page 83, Material of the nomen nudum lucidula referred here by Donisthorpe.)
- Francoeur, A.; Loiselle, R.; Buschinger, A. 1985. Biosystématique de la tribu Leptothoracini (Formicidae, Hymenoptera). 1. Le genre Formicoxenus dans la région holarctique. Nat. Can. (Qué.) 112: 343-403 (page 380, Senior synonym of picea)
- Kutter, H. 1977c. Hymenoptera, Formicidae. Insecta Helv. Fauna 6: 1-298 (page 144, see also)
- Mayr, G. 1855. Formicina austriaca. Beschreibung der bisher im österreichischen Kaiserstaate aufgefundenen Ameisen, nebst Hinzufügung jener in Deutschland, in der Schweiz und in Italien vorkommenden Arten. Verh. Zool.-Bot. Ver. Wien 5: 273-478 (page 419, male described; page 418, Combination in Formicoxenus, Senior synonym of laeviuscula)
- Nylander, W. 1846b. Additamentum adnotationum in monographiam formicarum borealium Europae. Acta Soc. Sci. Fenn. 2 2: 1041-1062 (page 1058, worker described)
- Nylander, W. 1849 . Additamentum alterum adnotationum in monographiam formicarum borealium. Acta Soc. Sci. Fenn. 3: 25-48 (page 34, queen described)