This subfamily is the predominant group of ants in North America. They are most common in the north and in the mountains with their numbers decreasing rapidly toward the southern part of the United States (Smith, D.R. 1979: 1422).
The formicines have long been considered close relatives of the dolichoderines and are believed to have separated from other ants early in their evolutionary history. Characteristics the two subfamilies have in common are:
Formicinae is the only subfamily lacking a pygidial gland, and it is believed to have split from all other ants very early in evolutionary history.
Worldwide, Formicinae has about 3700 species in 49 genera (Shattuck, 1999. Australian Ants: 86).
The tribal and generic taxonomy of the subfamily is not well understood.
Recognition. The mesosoma is attached to the gaster by a single segment. The gaster does not have constrictions between between segments. The sting is absent, and the tip of the gaster has a small circular opening (the acidopore) that is usually surrounded by a ring of short hairs.
Similar Subfamilies. Species of Formicinae are most commonly confused with species of Dolichoderinae since both subfamilies have the mesosoma attached to the gaster by a single segment, lack a sting, and often are of similar overall size and shape. However, formicines can always be separated from dolichoderines by the tip of the gaster; in formicines there is a small circular opening (most easily seen by the ring of hairs surrounding it) while all dolichoderines have a slit-like opening (this is usually not easily visible but its presence is inferred by a lack of an acidopore). Species of Ponerinae also have the mesosoma attached to the gaster by a single segment, but they are less likely to be confused with formicines since ponerines are generally smaller than formicines. Ponerines can be separated from all formicines by the lack of an acidopore, and many ponerines have a well developed sting (absent in formicines).
Nearctic Genera. Acanthomyops, Acropyga, Brachymyrmex, Camponotus, Formica, Lasius, Myrmelachista, Paratrechina, Plagiolepis, Polyergus, Prenolepis
Non-Nearctic Genera. Agraulomyrmex, Alloformica, Anoplolepis, Aphomomyrmex, Bajcaridris, Bregmatomyrma, Calomyrmex, Cataglyphis, Cladomyrma, Dendromyrmex, Echinopla, Euprenolepis, Forelophilus, Gesomyrmex, Gigantiops, Lasiophanes, Lepisiota, Melophorus, Myrmecocystus, Myrmecorhynchus, Myrmoteras, Notoncus, Notostigma, Oecophylla, Opisthopsis, Overbeckia, Petalomyrmex, Phasmomyrmex, Polyrhachis, Proformica, Prolasius, Pseudaphomomyrmex, Pseudolasius, Pseudonotoncus, Rossomyrmex, Santschiella, Stigmacros, Teratomyrmex
Tribes