Formica clara

Nests are often rather populous, monogynous to weakly polygynous, with aggressive workers which are, at least in the northern range, notably larger than those of Formica cunicularia and Formica rufibarbis. Larger nests defend their territories. Resistance against social parasites is certainly stronger than in F. cunicularia (Seifert 1997, 2007; Czechowski & Radchenko 2006); however, it is the main host of the slave-maker in Central Asia where F. cunicularia and F. rufibarbis are rare or absent. Alates occur in Central Europe 14 July ± 16 d [29 June, 20 July], n = 14 (Seifert & Schultz, 2009). Pashaei Rad et al. (2018) found this species in Iran on parkland ground in a moderate rainfall area.

Identification
Seifert and Schultz (2009) - A member of the Formica rufibarbis group. The distinction from the similar species Formica cunicularia and Formica clara sinae can be determined with a discrimination analysis.

The extreme colour differences and some morphometric deviation between the Syrian type series of F. clara and the northern F. lusatica population has suggested hetero-specificity in a time when the geographic variation of both taxa over their whole Palaearctic range has been poorly known (Seifert 1997). This situation has changed now – 200 nest samples from Eurasia with recording of the complete character set and 62 samples with incomplete character set became available during the last years. Considering all sixteen structural characters and two pigmentation characters, a principal component analysis gave no suggestion on a possible grouping according to geography. The assumed differences between northern and southern populations most probably represent intraspecific clinal variation. Indeed there are detectable some highly significant geographic trends: CS and CL / CW1.4 increase with growing geographical latitude while GHL / CS1.4 falls (all regressions with p < 0.0001).

Distribution
Seifert and Schultz (2009) - Shows the widest geographical range among all species of the F. rufibarbis group. Inhabits the temperate, submeridional and meridional zones of the Palaearctic, occurs between 2° and 88° E (as opposed to 120° E in F. clara sinae) and 31° and 61°N (in Finland). Having a planar to colline distribution in the northern parts of its European range, but climbing up to 3500 m at 31° N in the Himalayas.

Distribution based on Regional Taxon Lists
Oriental Region: India. Palaearctic Region: Afghanistan, Austria, Azerbaijan, Belgium, Bulgaria, China, Croatia, Czech Republic, Georgia, Germany, Greece, Hungary, Iran, Israel, Italy, Kyrgyzstan, Mongolia, Netherlands, Poland, Romania, Russian Federation, Slovakia, Slovenia, Spain, Switzerland, Turkey, Turkmenistan, United Kingdom of Great Britain and Northern Ireland.

Biology
Seifert and Schultz (2009) - Primarily a species of the dry steppes. Most thermophilic of the European species of the F. rufibarbis group (Seifert 1997, 2007) and in Central Europe the rarest of these species, with only regional occurrence in warm regions below 700 m, occurring here mainly on very xerothermic sandy and limestone grasslands, also on ruderal grassland, generally preferring open land with patchy herb layer. In sandy areas of the Lausitz (Germany) outcompeting F. rufibarbis. In the southern parts of the range also in more moist places, city parks and semi-shaded woodland.

Nomenclature

 *  clara. Formica rufibarbis var. clara Forel, 1886f: 206 (w.) RUSSIA. Ruzsky, 1902b: 471 (q.m.). Combination in F. (Serviformica): Emery, 1925b: 250. Subspecies of rufibarbis: Forel, 1901h: 65. Raised to species: Collingwood, 1961a: 68; Dlussky, 1967a: 77. Material of the unavailable names transversa, clara referred here by Dlussky, 1967a: 77. Senior synonym of rizadaghi: Dlussky, Soyunov & Zabelin, 1990: 139; of caucasica, lusatica: Seifert & Schultz, 2009: 263. See also: Czechowski, Radchenko, et al. 2012: 220. Current subspecies: nominal plus sinae.
 * caucasica. Formica rufibarbis var. caucasica Wheeler, W.M. 1913f: 517 (w.) CAUCASUS. [First available use of Formica rufibarbis subsp. clara var. caucasica Ruzsky, 1905b: 401; unavailable name.] Subspecies of rufibarbis: Stitz, 1930: 238. Junior synonym of glauca: Dlussky, 1967a: 74; of clara: Seifert & Schultz, 2009: 263..
 * rizadaghi. Formica (Serviformica) rizadaghi Arnol'di, 1968: 1819, figs. 19, 20 (w.q.) TURKMENIA. Junior synonym of clara: Dlussky, Soyunov & Zabelin, 1990: 139.
 * lusatica. Formica lusatica Seifert, 1997b: 13, figs. 2, 6 (w.) GERMANY. Czechowski & Radchenko, 2006: 260 (m.). Junior synonym of clara: Seifert & Schultz, 2009: 263.

Worker
Seifert and Schultz (2009) - Longer (CL / CW1.4 1.138), distance of lateral ocelli moderate (OceD / CS1.4 0.162); eye smaller than in F. cunicularia (EYE / CS1.4 0.290), petiole wide (PEW / CS1.4 0.467). Scape rather long (SL / CS1.4 1.080). Clypeus with sharp median keel and fine longitudinal microcarinulae. Frontal triangle finely transversely rippled and with 35 - 55 short pubescence hairs. Eyes with microsetae of 10 - 15 μm maximum length. Total mean of unilateral setae numbers on different body parts predicted for a specimen with CS = 1.4 mm: pronotum 3.2 (W-population: 3.6, E-population: 2.2), mesonotum 1.4 (W: 1.7, E: 0.8), petiole dorsal of spiracle 0.8 (W: 0.9, E: 0.6), flexor profile of hind tibia 0.6. Posterior margin and underside of head and dorsolateral metapleuron as a rule without setae. Ventral coxae with long setae. Dorsum of gaster normally with rather long setae, rarely these are missing. Dorsal mesonotal profile broadly rounded. Metanotal depression in larger individuals relatively deep. Propodeal dome in profile rectangular to round, the basal part sometimes rather linear to concave, whole propodeum flatter in smaller specimens. Dorsal crest of petiole in frontal view normally broadly convex, in smaller specimens sometimes bluntly angled, in larger specimens occasionally with weakly 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 4.4 μm) and covered by dense silvery pubescence (sqPDG 3.1). Pubescence on head, mesosoma and petiole dense. Typical size-dependent variation of colour pattern in the northern population (F. lusatica): smaller specimens: area between frontal carinae, posterior vertex, dorsal promesonotum, coxae, and all appendages dark brown, all other body parts light reddish; large specimens: whole dorsal head more or less reddish, whole mesosoma and petiole light reddish, but coxae remaining dark brown; gaster in all size-classes dark brown. Colouration in the southern population (F. clara) on average significantly lighter, with predominance of yellowish reddish pigmentation, though specimens with the whole body being more or less dark brown may occur. The type series of F. clara represents a colour extreme: all body parts pale yellowish red with exception of antennal funiculus and a patch on dorsocaudal head where brown colour components are added and the gaster which is light brown with a yellowish tinge or even yellowish red (reminiscent of Formica truncorum).

Type Material
Seifert and Schultz (2009) - F. clara: 9 syntype workers labelled “F. rufibarbis v. clara Forel, Damas (Lortet)”;.