Formica cunicularia

Species very common throughout Europe, even in disturbed habitats; also reported from Morocco (Rigato & Toni, 2011) and Russia (Zryanin & Zryanina, 2007). In Russia it is found in steppe habitats and dry pine forests. Nests are usually without mounds but mounds occur in some situations such as in meadows.

Identification
Seifert and Schultz (2009) - A member of the Formica rufibarbis group. The separation of F. cunicularia and Formica clara represents the most difficult discrimination problem within the Formica rufibarbis group because there is a deficiency of strongly discriminating structural characters.

The weak point is that intraspecific colour polymorphism and loss of pigmentation by light or storage media could possibly affect the reliability of the pigmentation characters PIGM and CONT, but just these two characters have the largest loadings (canonical correlations) in the DA. These loadings are 0.788 in PIGM1.4 and 0.391 in CONT1.4 but only 0.336 in EYE1.4 and 0.170 in nPN1.4, the two best structural discriminators. Another problem are the isolated West Mediterranean populations of F. cunicularia from Corsica, Sardinia and the Sierra Nevada which were all allocated in the DA to the F. cunicularia cluster but possibly represent a third species. Integrative approaches including DNA analysis could bring more clarity into this issue.

Collingwood (1979) - Ashy grey black with at least genae and mesopleural articulations reddish; often most of alitrunk and head may be reddish. Gula and occiput bare. Erect hairs normally absent on pronotum but occasionally one or two short erect hairs may be present on promesonotum, never on upper margin of scale. Length: 4.0-6.5 mm.

Distribution
Seifert and Schultz (2009) - Temperate, Ponto-south-Siberian and Submediterranean species of the West Palaearctic, occurring from southernmost England and Iberia to West Siberia (85° E). In northwestern Europe, it goes north to southern Sweden (58° N) but has not reached southern Finland so far. Having a planar to colline distribution in the northern parts of its range, it climbs up to 1800 m in the Alps, up to 2400 m in the Caucasus and up to 2000 m in the South Siberian Tarbagatay Mountains.

North Africa to South Scandinavia, Portugal to Urals (Collingwood 1979).

Distribution based on Regional Taxon Lists
Oriental Region: India. Palaearctic Region: Albania, Andorra, Armenia, Austria, Belarus, Belgium, Bulgaria, Channel Islands, China, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, Iberian Peninsula, Iran, Italy, Kyrgyzstan, Latvia, Lithuania, Luxembourg, Mongolia, Montenegro, Morocco, Netherlands, Norway, Poland, Portugal, Republic of Macedonia, Republic of Moldova, Romania, Russian Federation, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom of Great Britain and Northern Ireland.

Biology
Seifert and Schultz (2009) - Moderately thermophilic. Preferred habitats are meagre and semidry grasslands on differing geological outcrop, more rarely extremely xerothermic grasslands and also open ruderal, rural or disturbed habitats, including road or railway verges. In contrast to F. rufibarbis more frequently occurring on loamy soils with more developed herb layer and less often invading the urban zone. Colony foundation usually by single gynes but also pleometrotic. Nests moderately populous, usually containing 1000 - 1800 workers, sometimes weakly polygynous, but polydomous colonies unknown (as in all members of the group). Usually inhabits simple soil nests, construction of high mounds of mineral soil in meagre grassland with higher herb layer regularly observed. Usually timid and fugitive, but populous nests with large workers may be very aggressive during nest defence. Not territorial. Foraging at surface temperatures of up to 50°C, mainly on open surfaces and in the herb layer, but not avoiding bushes and trees. Zoophagous, trophobiotic and nectarivorous. Low position in dominance hierarchies of ant communities, usually inferior to even Lasius niger (Linnaeus, 1758), whom it carefully evades thanks to superior walking speed and well-developed visual sense, thus enabling coexistence at long-term food sources. May snatch large prey items from L. niger by swift surprise attack. Favoured host species for several socially parasitic ant species. Alates occur 7 July ± 12 d [16 June, 1 August], n = 17 (Seifert 2007).

Collingwood (1979) - This is a common species throughout Western Europe, nesting under stones or in small earth mounds, colonising railway embankments, sun exposed borders of woodland, dry open pasture and sea cliffs. Each nest is separate and normally has only one queen. Its habits are mainly predaceous and scavenging. Alatae occur in July and August

Romani et al. (2006) - This species is a host for the slave-making species Polyergus rufescens

Foraging/Diet
Formica cunicularia collect honeydew.

Novgorodova (2015b) investigated ant-aphid interactions of a dozen honeydew collecting ant species in Western Siberia pine and aspen-birch-pine forests (54°7´N, 83°06´E, 200 m, Novosibirsk) and mixed-grass-cereal steppes with aspen-birch groves (53°44´N, 78°02´E, 110 m, near Karasuk) in the Novosibirsk Region and coniferous forests in the northeastern Altai (north end of Lake Teletskoe, 51°48´N, 87°17´E, 434 m). All of the ants studied had workers that showed high fidelity to attending particular aphid colonies, i.e, individual foragers that collect honeydew tend to return to the same location, and group of aphids, every time they leave the nest. F. cunicularia honeydew collecting activities also showed some other specialization but this was dependent on colony size. Smaller colonies (hundreds of workers) did not specialize. Larger colonies (>1,000 workers), during the summer months when the aphids and ants were most active, had individual foragers that specialized on either collecting honeydew, guarding, i.e., protecting aphids from competitors, transporting honeydew, or scouting for new aphid colonies. Some individuals did not specialize and behaved like foragers from smaller colonies, while others would specialize by returning to a specific aphid colony but would as readily guard aphids as they would collect honeydew. F. cunicularia tended Chaitophorus populeti (Panzer) and Aphis craccivora Koch.

Guiliani et al. (2019) observed this species foraging on extrafloral nectaries of the invasive Reynoutria x bohemica (Polygonaceae) in Tuscany. The habitats examined were river banks and disturbed habitats.

Other Insects
This ant has been associated with the butterfly (Obregon et al. 2015).

Nomenclature

 *  cunicularia. Formica cunicularia Latreille, 1798: 40 (w.q.m.) FRANCE. Combination in F. (Serviformica): Forel, 1915d: 64. Junior synonym of rufibarbis: Walckenaer, 1802: 161; Dalla Torre, 1893: 209; Ruzsky, 1905b: 385; Forel, 1915d: 64; Emery, 1916b: 255; Emery, 1925b: 250. Revived from synonymy and status as species: Yarrow, 1954a: 231. Senior synonym of rubescens: Yarrow, 1954a: 231; Dlussky, 1967a: 73; Bernard, 1967: 296; Seifert & Schultz, 2009: 261; of fuscorufibarbis: Dlussky, 1967a: 73; Dlussky & Pisarski, 1971: 166; of glebaria: Bernard, 1967: 296; Boven, 1977: 164; Agosti & Collingwood, 1987a: 59; of glauca (and its junior synonyms caucasica, katuniensis, montivaga, montaniformis, volgensis): Atanassov & Dlussky, 1992: 267; of fuscoides: Arakelian, 1994: 94; Seifert & Schultz, 2009: 261.
 * fuscorufibarbis. Formica fusca var. fuscorufibarbis Forel, 1874: 54 (w.q.) SWITZERLAND. Combination in F. (Serviformica): Forel, 1915d: 63. Raised to species: Forel, 1906c: 189. Subspecies of glebaria: Bondroit, 1918: 50; of rufibarbis: Dalla Torre, 1893: 210; Stitz, 1939: 357; Novak & Sadil, 1941: 107. Junior synonym of rufibarbis: Bernard, 1967: 297; of cunicularia: Dlussky, 1967a: 73; Dlussky & Pisarski, 1971: 166. See also comment in Seifert, 2002b: 266.
 * rubescens. Formica fusca var. rubescens Forel, 1904f: 423 (w.) SWITZERLAND. [Unresolved junior primary homonym of rubescens Leach, above.] Emery, 1909b: 196 (q.); Wheeler, W.M. 1913f: 498 (m.). Subspecies of glebaria: Bondroit, 1918: 50; Boven, 1947: 188. Junior synonym of cunicularia: Yarrow, 1954a: 231; Dlussky, 1967a: 73; Bernard, 1967: 296; Seifert & Schultz, 2009: 261.
 * fuscoides. Formica (Serviformica) cunicularia subsp. fuscoides Dlussky, 1967a: 74 (w.q.m.) ARMENIA. Junior synonym of cunicularia: Arakelian, 1994: 94; Seifert & Schultz, 2009: 261.

Type Material
Seifert and Schultz (2009) - Neotype worker labelled “FRA: 44.4947°N, 0.9597°E, Fumel, 120 m, in a garden, leg. Galkowski 2008.07.25” and “Neotype Formica cunicularia Latreille 1798, des. Seifert & Schultz 2009”; SMN Görlitz. In case of destruction or loss of the neotype specimen, a replacement neotype can be designated from a series of five mounted workers from the same nest series in SMN Görlitz and further five workers in Paris.

Justification of the neotype fixation: A current search in the Latreille collection of MNHN Paris failed to detect a specimen interpretable as a primary type (J. Casevitz-Weulersse, pers. comm. 2008) and the literature gives no indication that a revisor ever has seen one. In order to establish an unambiguous standard for differentiation from similar species, we fixed a neotype in a sample from the terra typica which is in agreement with the traditional morphological conception of F. cunicularia.

Taxonomic Notes
Seifert and Schultz (2009) - West Mediterranean isolated populations: We do not at this time propose these deviating and isolated populations from Corsica, Sardinia and the Sierra Nevada as heterospecific from F. cunicularia. Differences to the continental population are a significantly narrower petiole (PEW / CS1.4 0.433) and slightly longer 1st tergite setae (GHL / CS1.4 7.24%). It seems to be the only species of the group from Corsica where Formica clara and Formica rufibarbis have not been reported so far.

Worker
Seifert and Schultz (2009) - Medium-sized Serviformica species (CS 1.365 mm); head slightly elongated (CL / CW1.4 1.131); Scape moderately long SL / CS1.4 1.073; distance of lateral ocelli moderate (OceD / CS1.4 0.164); eyes rather large (EYE / CS1.4 0.301), petiole rather wide (PEW / CS1.4 0.468). Clypeus with sharp median keel and fine longitudinal micro-carinulae. Frontal triangle finely transversely rippled and with 30 - 60 short pubescence hairs. Eyes with microsetae of 7 - 13 μm maximum length. Total mean of unilateral setae numbers on different body parts predicted for a specimen with CS = 1.4 mm: pronotum 1.1, mesonotum 0.8, petiole scale dorsal of spiracle 0.25, flexor profile of hind tibia 0.3. Posterior margin and underside of head and dorsolateral metapleuron as a rule without setae. Ventral coxae with long setae, dorsum of gaster with scattered, moderately long setae. Dorsal mesonotum in lateral aspect broadly rounded. Metanotal depression in larger individuals relatively deep. Propodeal dome rounded in lateral view, basal profile sometimes concave and in smaller specimens often straight. Dorsal crest of petiole in frontal view bluntly angled in smaller specimens to broadly convex in larger specimens, in some of the large individuals with straight or weekly excavate median portion. Petiole scale in lateral aspect rather thin, with convex anterior and more straight posterior profile. Gaster with transverse microripples of small average distance (RipD 4.6 μm) and covered by dense silvery pubescence (sqPDG 3.1). Pubescence on head, mesosoma and petiole dense. Typical colour pattern: Head with exception of round reddish-yellowish spots on anterior genae, dorsal promesonotum, coxae and all appendages dark brown, gaster blackish brown. Other body parts more or less reddish-yellowish. Nests with much lighter specimens having whole mesosoma, coxae and petiole uniformly reddish and such with very dark specimens having the reddish pigmentation reduced to a very small spot on frontal margin of ventrolateral mesonotum; exceptionally completely dark specimens occur.