The Formicinae are a subfamily within the Formicidae containing ants of moderate evolutionary development. Formicines retain some primitive features, such as the presence of cocoons around pupae, the presence of ocelli in workers, and little tendency toward reduction of palp or antennal segmentation in most species, except subterranean groups. Extreme modification of mandibles is rare, except in the genera Myrmoteras and Polyergus. However, some members show considerable evolutionary advancement in behaviors such as slave-making and symbiosis with root-feeding hemipterans. Finally, all formicines have very reduced stings and enlarged venom reservoirs, with the venom gland, specialized (uniquely among ants) for the production of formic acid. All members of the Formicinae "have a one-segmented petiole in the form of a vertical scale". Identification Formicine ants have a single node-like or scale-like petiole (postpetiole entirely lacking) and the apex of the abdomen has a circular or U-shaped opening (the acidopore), usually fringed with hairs. A functional sting is absent, and defense is provided by the ejection of formic acid through the acidopore. If the acidopore is concealed by the pygidium and difficult to discern, then the antennal sockets are located well behind the posterior margin of the clypeus (cf. Dolichoderinae). In most formicines, the eyes are well developed (ocelli may also be present), the antennal insertions are not concealed by the frontal carinae, and the promesonotal suture is present and flexible. Tribes and genera The tribal structure of the Formicinae is not completely understood. This list follows the scheme at AntCat, but other schemes and names are used. Camponotini Forel, 1878 Calomyrmex Emery, 1895 Camponotus Mayr, 1861 – carpenter ants (global) †Chimaeromyrma Dlussky, 1988 Colobopsis Mayr, 1861 Dinomyrmex Ashmead, 1905 Echinopla Smith, 1857 Opisthopsis Dalla Torre, 1893 Overbeckia Viehmeyer, 1916 Polyrhachis Smith, 1857 (Asian, African tropics) †Pseudocamponotus Carpenter, 1930 Formicini Latreille, 1809 Alloformica Dlussky, 1969 Bajcaridris Agosti, 1994 Cataglyphis Foerster, 1850 †Cataglyphoides Dlussky, 2008 †Conoformica Dlussky, 2008 Formica Linnaeus, 1758 Iberoformica Tinaut, 1990 Polyergus Latreille, 1804 – Amazon ants Proformica Ruzsky, 1902 †Protoformica Dlussky, 1967 Rossomyrmex Arnol'di, 1928 Gesomyrmecini Ashmead, 1905 Gesomyrmex Mayr, 1868 †Prodimorphomyrmex Wheeler, 1915 Santschiella Forel, 1916 †Sicilomyrmex Wheeler, 1915 Gigantiopini Ashmead, 1905 Gigantiops Roger, 1863 (Neotropical) Lasiini Ashmead, 1905 Acropyga Roger, 1862 Anoplolepis Santschi, 1914 Cladomyrma Wheeler, 1920 †Glaphyromyrmex Wheeler, 1915 Lasiophanes Emery, 1895 Lasius Fabricius, 1804 Myrmecocystus Wesmael, 1838 Prolasius Forel, 1892 Stigmacros Forel, 1905 Teratomyrmex McAreavey, 1957 Melophorini Forel, 1912 Melophorus Lubbock, 1883 (Australian) Myrmecorhynchini Wheeler, 1917