''Eciton'' is a

New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. ...

army ant The name army ant (or legionary ant or ''marabunta'') is applied to over 200 ant species in different lineages. Because of their aggressive predatory foraging groups, known as "raids", a huge number of ants forage simultaneously over a limi ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

that contains the most familiar

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of army ants. The most predominant and well-known species is '' Eciton burchellii'', which is also more commonly known as the army ant and is considered the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

. '' Eciton burchellii'' and '' Eciton hamatum'' are the most visible and best studied of the New World army ants because they forage above ground and during the day, in enormous raiding swarms. Their range stretches from southern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

to the northern part of

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

Life cycle

''Eciton'' army ants have a bi-phasic lifestyle in which they alternate between a nomadic phase and a statary phase. In the statary phase, which lasts about three weeks, the ants remain in the same location every night. They arrange their own living bodies into a nest, protecting the queen and her eggs in the middle. Such a temporary home is called a " bivouac". In the nomadic phase the ants move their entire

colony In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state' ...

to a new location nearly every night for about two weeks on end. When the ants enter the statary phase, the queen's body swells massively and she lays as many as 80,000 eggs in less than a week. While the eggs mature, the ants swarm with less frequency and intensity. When the eggs hatch, the excitement caused by the increased activity of the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e causes the colony to enter the nomadic phase. The colony swarms much more intensely and does so nearly every day, and the ants move to a new location nearly every night. After two weeks, around the time when the larvae begin to

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...

te, the colony again enters the statary phase, and the cycle begins anew. Because of the regularity and intensity of ''E. burchelli'' and ''E. hamatum'' swarms, many insect and bird species have evolved complex relationships with these ants. There are conopid flies (the entire genus ''

Stylogaster The conopid genus ''Stylogaster'' is a group of unusual flies. It is the only genus in the subfamily Stylogastrinae, which some authorities have historically treated as a separate family Stylogastridae (or Stylogasteridae). Biology Stylogastr ...

'') that are obligate associates of army ant raids, and females lay their eggs on insects (mostly

crickets Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 8 ...

and roaches) flushed into the open by the ants, and there are also some

tachinid The Tachinidae are a large and variable family of true flies within the insect order Diptera, with more than 8,200 known species and many more to be discovered. Over 1,300 species have been described in North America alone. Insects in this family ...

flies that are somewhat similar in behavior. There are ant-mimicking staphylinid beetles, shaped like the ants they follow, that run with the swarm, some of them preying on stragglers or other insects injured or flushed by army-ant activity, though most of these are

inquiline In zoology, an inquiline (from Latin ''inquilinus'', "lodger" or "tenant") is an animal that lives commensally in the nest, burrow, or dwelling place of an animal of another species. For example, some organisms such as insects may live in the h ...

s in the ant nest; these and other insects sometimes spend their entire lives hidden in ''Eciton'' colonies, often mimicking the ants or their larvae. Many species of birds — mostly

cuckoo Cuckoos are birds in the Cuculidae family, the sole taxon in the order Cuculiformes . The cuckoo family includes the common or European cuckoo, roadrunners, koels, malkohas, couas, coucals and anis. The coucals and anis are sometimes separ ...

woodcreeper The woodcreepers (Dendrocolaptinae) comprise a subfamily of suboscine passerine birds endemic to the Neotropics. They have traditionally been considered a distinct family Dendrocolaptidae, but most authorities now place them as a subfamily of th ...

tanager The tanagers (singular ) comprise the bird family Thraupidae, in the order Passeriformes. The family has a Neotropical distribution and is the second-largest family of birds. It represents about 4% of all avian species and 12% of the Neotropica ...

s, and

antbird The antbirds are a large passerine bird family, Thamnophilidae, found across subtropical and tropical Central and South America, from Mexico to Argentina. There are more than 230 species, known variously as antshrikes, antwrens, antvireos, fire ...

s — feed near the swarms. About 50 of the approximately 200 species of antbirds specialize in preying on insects fleeing the ants, getting up to half their food this way. Some of these birds actively check army-ant bivouacs each morning and follow the foraging trail to the swarm front, where they take positions based on their species' relations in a dominance hierarchy. A swarm may be attended by as many as 25 birds of one or two "professional" species and individual birds of as many as 30 other species. There are even butterflies (esp. the family Hesperiidae) that feed almost exclusively on the feces of these bird species.

Parasites

The

mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear e ...

'' Trichocylliba crinita'' (Elzinga & Rettenmeyer, 1975) (

Mesostigmata Mesostigmata is an order of mites belonging to the Parasitiformes. They are by far the largest group of Parasitiformes, with over 8,000 species in 130 families. Mesostigmata includes parasitic as well as free-living and predatory forms. They can ...

: Uropodidae) was found on the jaws of the species '' Eciton dulcium'', and nowhere else.Picture
(hairy brown spheres are the mites)

Species

*'' Eciton burchellii'' (Westwood, 1842) *'' Eciton drepanophorum'' Smith, 1858 *'' Eciton dulcium'' Forel, 1912 *'' Eciton hamatum'' (Fabricius, 1782) *'' Eciton jansoni'' Forel, 1912 *'' Eciton lucanoides'' Emery, 1894 *'' Eciton mexicanum'' Roger, 1863 *'' Eciton quadriglume'' (Haliday, 1836) *''

Eciton rapax ''Eciton'' is a New World army ant genus that contains the most familiar species of army ants. The most predominant and well-known species is ''Eciton burchellii'', which is also more commonly known as the army ant and is considered the type spec ...

'' Smith, 1855 *'' Eciton setigaster'' Borgmeier, 1953 *'' Eciton uncinatum'' Borgmeier, 1953 *'' Eciton vagans'' (Olivier, 1792)

References

External links

Tree of Life - Eciton

Discover Life - Formicidae: Eciton

''Eciton'' of Costa Rica
{{Taxonbar, from=Q1932529 Dorylinae Ant genera Hymenoptera of South America Hymenoptera of North America