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Formica Temporal range: Eocene-present, | |
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Formica rufa | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hymenoptera |
Family: | Formicidae |
Subfamily: | Formicinae |
Tribe: | Formicini |
Genus: | Formica Linnaeus, 1758 |
Type species | |
Formica rufa [1] | |
Diversity [2] | |
234 species | |
Synonyms | |
AdformicaLomnicki, 1925 Contents |
Formica is a genus of ants of the subfamily Formicinae, including species commonly known as wood ants, mound ants, thatching ants, and field ants. Formica is the type genus of the Formicidae, and of the subfamily Formicinae. [3] The type species of genus Formica is the European red wood ant Formica rufa . [1] Ants of this genus tend to be between 4 and 8 mm long. [4] Ants belonging to the Formica genus possess a single knob or bump located between their thorax and abdomen. These ants primarily feed on honeydew, a sugary liquid produced by aphids. Formica ants appear to take on a shepherding role with smaller aphids, relocating them to different parts of plants to ensure a continuous food source for the aphids. By doing so, the ants can establish a relatively sustainable honeydew supply for both themselves and their colony. [5]
As the name wood ant implies, many Formica species live in wooded areas [6] where no shortage of material exists with which they can thatch their mounds (often called anthills [7] ). One shade-tolerant species is F. lugubris . However, sunlight is important to most Formica species, and colonies rarely survive for any considerable period in deeply shaded, dense woodland. The majority of species, especially outside the F. rufa species group, are inhabitants of more open woodlands or treeless grassland or shrubland. In North America, at least, these habitats had a long history of frequent landscape-scale fires that kept them open before European settlement. Conversion to agriculture and fire suppression have reduced the abundance of most American Formica species, while the cessation of traditional haycutting seems to have had the same effect in Europe. However, at least a few Formica species may be found in a wide range of habitats from cities to seasides to grasslands to swamps to forests of the temperate Northern Hemisphere.[ citation needed ]
In more suburban landscapes, they tend to nest near structures such as sidewalks, fences, or building foundations. [4]
Mound-building, forest-dwelling Formica species groups such as F. rufa often have a considerable effect on their environments. They maintain large populations of aphids on the secretions of which they feed, and which the ants defend from other predators. [8] They also prey on other insects. In fact, in many countries, they are introduced in forests to control tree pests, such as swains jack pine sawfly and eastern tent caterpillars in North America. The effects of mound-building grassland species such as F. montana are not well-studied, but their local abundance, conspicuous mound-building, and very frequent association with aphids and membracids point to a comparably important ecological role.[ citation needed ]
Formica nests are of many different types from simple shaft-and-chamber excavations in soil with a small crater or turret of soil above to large mounds, under stones or logs, or in stumps. None is arboreal. The genus is abundant in both the Nearctic and Palearctic regions. Due to their relatively large size and diurnal activity, they are among the more commonly seen ants in northern North America.[ citation needed ] Some species, including F. rufa , which is common in Southern England, make large, visible thatch nests of dry plant stems, leaves, or conifer needles, usually based around a rotting stump.
Most Formica species are polygynous (have multiple queens per colony), and some are polydomous (have multiple nests belonging to the same colony). [9] Queens may be singly or multiply mated, and may or may not be related. Formica polyctena has polygynous colonies. [10]
Wood ants typically secrete formic acid; F. rufa can squirt the acid from its acidopore several feet if alarmed, a habit which may have given rise to the archaic term for ant, "pismire", and by analogy its American equivalent "piss-ant". They can be relatively large; F. rufa workers can reach a maximum length around 10 mm. The eastern US species F. dolosa and the western F. ravida (syn. F. haemorrhoidalis) may be slightly longer.[ citation needed ]
Ants are eusocial organisms – the individuals of the species work together to survive, produce the next generation, and accomplish tasks which cannot be accomplished alone. [11] Unlike other ants, the genus Formica does not have separate castes, which are based on an individual's specialization and morphology. For example, F. selysi , a species native to floodplains, has developed a method to deal with flooding. Individual ants come together to form a living raft to survive the flood. Individual ants tend to take the position in the raft which they held in the past. This return to the same role in the raft is an example of specialization. [11]
Formica ants are notable for their socially parasitic behaviors. The three categories are: [12]
Some species of this group need to do this to survive, for others it is optional.[ citation needed ]
As of 2018 [update] , Formica contains at least 290 extant species and 59 extinct species. [2] [14]
Species include: [15]
Formica exsecta is a species of ant found from Western Europe to Asia.
Formica rufibarbis is a European formicine ant of the Formica fusca group. In the classification by Auguste Forel, it is treated in the subgenus Serviformica. F. rufibarbis is subject to a Species Action Plan (SAP) in England, where it is known from only two locations, although it is not considered to be at risk on continental Europe.
Ponerinae, the ponerine ants, is a subfamily of ants in the Poneromorph subfamilies group, with about 1,600 species in 47 extant genera, including Dinoponera gigantea - one of the world's largest species of ant. Mated workers have replaced the queen as the functional egg-layers in several species of ponerine ants. In such queenless species, the reproductive status of workers can only be determined through ovarian dissections.
The Formica rufa group is a subgeneric group within the genus Formica, first proposed by William Morton Wheeler. This group contains the mound-building species of Formica commonly termed "wood ants" or "thatch-mound ants", which build prominent nests consisting of a mound of grass, litter, or conifer needles. The species Formica rufa or the red wood ant is the type species of this subgroup.
Formica rufa, also known as the red wood ant, southern wood ant, or horse ant, is a boreal member of the Formica rufa group of ants, and is the type species for that group, being described already by Linnaeus. It is native to Eurasia, with a recorded distribution stretching from the middle of Scandinavia to the northern Iberia and Anatolia, and from Great Britain to Lake Baikal, with unconfirmed reportings of it also to the Russian Far East. There are claims that it can be found in North America, but this is not confirmed in specialised literature, and no recent publication where North American wood ants are listed mentions it as present, while records from North America are all listed as dubious or unconfirmed in a record compilation. The workers' heads and thoraces are colored red and the abdomen brownish-black, usually with dark patches on the head and promensonotum, although some individuals may be more uniform reddish and even have some red on the part of the gaster facing the body. In order to separate them from closely related species, specimens needs to be inspected under magnification, where difference in hairiness are among the telling characteristics, with Formica rufa being hairier than per example Formica polyctena but less hairy than Formica lugubris. Workers are polymorphic, measuring 4.5–9 mm in length. They have large mandibles, and like many other ant species, they are able to spray formic acid from their abdomens as a defence. Formic acid was first extracted in 1671 by the English naturalist John Ray by distilling a large number of crushed ants of this species. Adult wood ants primarily feed on honeydew from aphids. Some groups form large networks of connected nests with multiple queen colonies, while others have single-queen colonies.
Formica fusca is a black-colored ant commonly found throughout Europe as well as parts of southern Asia and Africa. It has the common names silky ant or dusky ant. The range within the palaearctic region extends from Portugal in the west to Japan in the east and from Italy in the south to Fennoscandia in the north. Populations from North America have been split off as a separate species, Formica subaenescens. F. fusca nests are usually found in rotten tree stumps or under stones in clearcut areas and along woodland borders and hedgerows. The species also often occurs in urban areas, feeding on honeydew secreted by the aphids found on weeds.
Formica lugubris, also known as the hairy wood ant is commonly found in wooded upland areas across northern Eurasia. Colonies construct large thatched mound nests occupied by thousands of workers, and one or more queens. Workers look similar to other species of wood ants, but Formica lugubris workers can be identified by a fringe of hairs that reaches down to their eyes and prominent hairs between the facets of their compound eyes. Workers can reach sizes of up to 9 mm long; queens are larger, reaching 12 mm long.
Formica polyctena is a species of European red wood ant in the genus Formica and large family Formicidae. The species was first described by Arnold Förster in 1850. The latin species name polyctena is from Greek and literally means 'many cattle', referring to the species' habit of farming aphids for honeydew food. It is found in many European countries. It is a eusocial species, that has a distinct caste system of sterile workers and a very small reproductive caste. The ants have a genetic based cue that allow them to identify which other ants are members of their nest and which are foreign individuals. When facing these types of foreign invaders the F. polyctena has a system to activate an alarm. It can release pheromones which can trigger an alarm response in other nearby ants.
Formica pratensis, the black-backed meadow ant, is a species of European red wood ant in the family Formicidae.
Formica sanguinea, or blood-red ant, is a species of facultative slave-maker ant in the genus Formica characterized by the ability to secrete formic acid. It ranges from Central and Northern Europe through Russia to Japan, China, the Korean Peninsula, Africa and also the United States. This species is coloured red and black with workers up to 7 mm long.
Camponotus vagus is a species of large, black, Palaearctic carpenter ant with a wide range that includes much of Europe, a large area of Asia, and part of Africa.
Dolichoderus is a genus of ants found worldwide.
Ypresiomyrma is an extinct genus of ants in the subfamily Myrmeciinae that was described in 2006. There are four species described; one species is from the Isle of Fur in Denmark, two are from the McAbee Fossil Beds in British Columbia, Canada, and the fourth from the Bol’shaya Svetlovodnaya fossil site in Russia. The queens of this genus are large, the mandibles are elongated and the eyes are well developed; a stinger is also present. The behaviour of these ants would have been similar to that of extant Myrmeciinae ants, such as solitary foraging for arthropod prey and never leaving pheromone trails. The alates were poor flyers due to their size, and birds and animals most likely preyed on these ants. Ypresiomyrma is not assigned to any tribe, and is instead generally regarded as incertae sedis within Myrmeciinae. However, some authors believe Ypresiomyrma should be assigned as incertae sedis within Formicidae.
Gesomyrmex is a genus of ants in the subfamily Formicinae. The genus contains six extant species, known from the Indomalayan realm, and nine fossil species. Of the extant species, four are known only from workers and two only from females. The extinct species "G. expectans" and "Gesomyrmex miegi", formerly placed in the genus, were excluded by Dlussky et al.., 2009.
Slave-making ants or slaver ants are brood parasites that capture broods of other ant species to increase the worker force of their colony. After emerging in the slave-maker nest, slave workers work as if they were in their own colony, while parasite workers only concentrate on replenishing the labor force from neighboring host nests, a process called slave raiding.
Formica incerta is a species of ant found in eastern North America. It is the most common species of Formica in many areas, and excavates underground nests with small entrance holes. Its diet includes nectar produced by extrafloral nectaries and honeydew, which it obtains from aphids and treehoppers. It is the main host for the slave-making ant Polyergus lucidus. F. incerta was first described by Italian entomologist Carlo Emery in 1893. Its specific name comes from the Latin incertus meaning "uncertain" and seems particularly apt given the subsequent uncertainty as to the validity of the species and the difficulty in distinguishing this ant from other species living in the same area.
Casaleia is an extinct genus of ants in the formicid subfamily Amblyoponinae described by Pagliano & Scaramozzino in 1990 from fossils found in Europe. The genus contains four species dating from the Eocene to Miocene, Casaleia eocenica, Casaleia inversa, Casaleia longiventris, Casaleia orientalis.
Formica biamoensis is an extinct species of formicid in the ant subfamily Formicinae known from fossils found in eastern Asia.
Formica paleosibirica is an extinct species of formicid in the ant subfamily Formicinae known from fossils found in eastern Asia.