Formicini

Radchenko and Khomych (2020) - Late Eocene European ambers. Different authors have diagnosed Formicini by a combination of various morphological features (Agosti, 1990, 1994; Agosti, Bolton, 1990; Bolton, 2003; Dlussky, 2008; Ward et al., 2016), the most distinctive of which, to our opinion, are: metacoxae are closely approximated, when coxae directed outward, their inner margins touch or almost touch each other; metatibiae are with a double row of stout setae (bristles); propodeal spiracles are elliptical to slit-shaped and located on a distance from the margin between the lateral and posterior surfaces of propodeum; eyes located behind the midlength of sides of head; ocelli in workers present; antennae 12-segmented (13-segmented in males), inserted close to the posterior margin of clypeus.

Nevertheless, any of the mentioned characters cannot be considered as a true synapomorphy for this tribe, and occurred in various combinations in other tribes of Formicinae. Moreover, some of these traits are absent in the extant socially parasitic genera (Polyergus and Rossomyrmex); in Conoformica ocelli are absent and propodeal spiracles are small and rounded, and tibiae lack row of the coarse setae in Cataglyphoides intermedius and Cataglyphoides dlusskyi.

Beside three extinct Formicini genera, nine “good” fossil Formica species are known from the late Eocene European ambers. Despite some of them are superficially similar to several extant species, in general all late Eocene Formica constitute quite an archaic group and any of them most probably cannot be considered as a direct ancestor of modern species. Protoformica by the set of characters is intermediate between the extant genera Alloformica, Formica, Proformica, and Cataglyphis and also cannot be considered as an ancestor of any of the mentioned genera; Conoformica has no analogues in the modern fauna at all (Dlussky, 2008). Dlussky (2008) suggested Cataglyphoides may well be regarded as the ancestral with respect to Cataglyphis, but we disagree with this opinion (see Cataglyphoides).

Nomenclature

 * [tribe of Formicinae]
 * Formicariae Latreille, 1809: 124. Type-genus: Formica Linnaeus, 1758: 579.

Taxonomic History

 * Formicini as group name: Latreille, 1809: 124 [Formicariae].
 * Formicini as tribe of Camponotidae: Forel, 1891b: 79 [Formicii].
 * Formicini as tribe of Camponotinae: Forel, 1893a: 165 [Formicii]; Emery, 1895j: 772 [Formicii]; Forel, 1899c: 125 [Formicii]; Ruzsky, 1902d: 8 [Formicii]; Ruzsky, 1905b: 110 [Formicii]; Wheeler, W.M. 1910g: 143 [Formicii]; Wheeler, W.M. 1915h: 120; Forel, 1917: 249.
 * Formicini as tribe of Formicinae: Ashmead, 1905b: 384 [Formicini]; Bondroit, 1918: 36; Wheeler, W.M. 1922a: 693; Emery, 1925b: 240; subsequent authors; Bolton, 2003: 27, 126; Ward, et al. 2016: 346.

Taxonomic References
Forel, 1893a: 165 (synoptic classification); Emery, 1895j: 772 (synoptic classification); Forel, 1917: 249 (synoptic classification); Wheeler, W.M. 1922a: 698 (genera key); Emery, 1925b: 240 (diagnosis, genera key, catalogue); Wheeler, G.C. & Wheeler, J. 1970: 652 (larva diagnosis); Wheeler, G.C. & Wheeler, J. 1976b: 62 (larvae, review and synthesis); Dlussky & Fedoseeva, 1988: 77 (synoptic classification); Hölldobler & Wilson, 1990: 18 (synoptic classification); Agosti, 1990a: 295 (review of tribe, diagnosis); Agosti, 1991: 295 (Formica genus group diagnosis); Agosti, 1994a: 95 (diagnosis, revision of genera, phylogeny, key); Bolton, 1994: 50 (synoptic classification); Bolton, 1995a: 1039 (census); Bolton, 1995b: 12 (catalogue); Bolton, 2003: 27, 126 (diagnosis, synopsis); Dlussky, 2008a: 57 (Europe Eocene amber species key); Ward, et al. 2016: 346 (synopsis).