Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
(ants), a family of insects of the order Hyme-noptera (sometimes considered a superfamily). Worker ants are from 0.8 to 30 mm long; the queens are much larger because of the distention of the abdomen by eggs. In contrast to other insects of the order Hymenoptera, ants have a thin, mobile pedicel consisting of one or two segments that join the abdomen to the thorax. Each leg has one trochanter; metathoracic glands are located at the bases of the posterior legs. The thin antennae usually have an elongated first segment that forms the shaft of the antenna (scape). The wings have incomplete and sometimes very simplified veining; in many species, wings are absent.
There are nine or ten subfamilies of Formicidae, comprising 360 genera (with approximately 7, 000 species). Six subfamilies are found in the USSR: Ponerinae (six genera, with ten species), Dorylinae (one species), Leptanillinae (one species), Myrmicinae (24 genera, with more than 150 species), Dolichoderinae (four genera, with about 15 species), and Formicinae (12 genera, with more than 90 species). Formicidae are thermophilic; thus, the number of species, as well as the number of individuals, decrease from the tropical to the temperate latitudes. This distribution is also characteristic in the USSR: in the Caucasus there are more than 160 species, in the Eastern Ukraine 74 species, in Moscow Oblast 40 species, and in Arkhangel’sk Oblast only 24 species. The forest tundra is the northern boundary of Formicidae distribution.
Ants are social insects; they live in collective nests. In addition to winged males and females, a nest has one or several wingless egg-laying females, or queens, and numerous wingless workers (sexually underdeveloped females), which are often subdivided morphologically and behaviorally into a number of groups (thus, in some species large-headed soldiers are distinguished). The winged males and females, which develop in nests, fly away in the warm season for mating. After mating, the males die and the females lose their wings and proceed to form new nests.
Family life, particularly in higher ants, is complex and diverse. At the basis of the family’s existence are trophallaxis—the exchange between individuals of food and glandular secretions—and the very close relationship between the queen and the workers. Colonies of several friendly nests, among which there is exchange of food and individuals, are characteristic of a number of ant species. Colonies guard their territory together and do not allow ants from “alien” nests to enter.
Some ants have close associations with certain plants; for example, some settle in the thorns or hollow stems of plants, and others feed on secretions from special plant glands.
Because of the large number of individuals in many species, such as the wood ants of the genus Formica or the pavement ant, the Formicidae play an important role in biocenoses of forests and steppes. Ants destroy small invertebrates. They are also found in symbiotic relationships (trophobiosis) with sucking insects, primarily aphids; these relationships indirectly harm orchards and forests. Because of the predatory nature of ants, the insects are used in the control of leaf- and needle-chewing tree pests; some species of wood ants are artificially resettled for this purpose. In view of the important beneficial role of the Formicidae in biocenoses in a number of countries, including the USSR, measures are being adopted for the preservation of the Formicidae and their nests.
REFERENCESKaravaev, V. Fauna Rodyny Formicidae (murashky) Ukrainy, parts 1–2. Kiev, 1934–36.
Dlusskii, G. M. Murav’i roda Formika. Moscow, 1967.
Wheeler, W. T. Ants: Their Structure, Development and Behavior, 3rd ed. New York, 1960.
Bernard, F. Les Fourmis (Hymenoptera formicidae) d’Europe occidentale et septentrionale. Paris, 1968.
K. V. ARNOL’DI