''Formica incerta'' is a

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 ...

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

found in eastern North America. It is the most common species of ''

Formica ''Formica'' is a genus of ants of the family Formicidae, 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. The type species of genus ''For ...

'' in many areas, and excavates underground nests with small entrance holes. Its diet includes nectar produced by

extrafloral nectaries Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to anim ...

and honeydew, which it obtains from

aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

s and

treehopper Treehoppers (more precisely typical treehoppers to distinguish them from the Aetalionidae) and thorn bugs are members of the family (biology), family Membracidae, a group of insects related to the cicadas and the leafhoppers. About 3,200 species ...

s. It is the main host for the

slave-making ant Slave-making 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 onl ...

'' Polyergus lucidus''. ''F. incerta'' was first described by Italian

entomologist Entomology () is the scientific study of insects, a branch of zoology. In the past the term "insect" was less specific, and historically the definition of entomology would also include the study of animals in other arthropod groups, such as arach ...

Carlo Emery Carlo Emery (25 October 1848, Naples – 11 May 1925) was an Italian entomologist. He is remembered for Emery's rule, which states that insect social parasitism (biology), social parasites are often closely related to their hosts. Early in hi ...

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.

Description

A worker of ''F. incerta'' is very similar in appearance to '' Formica pallidefulva'', but the former has a few

chaeta A chaeta or cheta (from Greek χαίτη “crest, mane, flowing hair"; plural: chaetae) is a chitinous bristle or seta found in annelid worms, (although the term is also frequently used to describe similar structures in other invertebrates suc ...

e on the

mesosoma The mesosoma is the middle part of the body, or tagma, of arthropods whose body is composed of three parts, the other two being the prosoma and the metasoma. It bears the legs, and, in the case of winged insects, the wings. In hymenopterans of t ...

and around the petiole, while the latter does not. ''F. incerta'' is a slightly paler colour and less glossy than ''F. pallidefulva'' but considerable variability exists between specimens and between colonies. The queen is larger than the workers and can be distinguished from a queen of other species by three dark spots on her thorax.

Distribution and habitat

''Formica incerta'' is native to the eastern half of the United States. Its range extends from Minnesota, Nebraska, New England, and the

Appalachian balds In the Appalachian Mountains of the eastern United States, balds are mountain summits or crests covered primarily by thick vegetation of native grasses or shrubs occurring in areas where heavy forest growth would be expected. Balds are found prim ...

southwards to Colorado and possibly New Mexico. It is present in sandy and clayey soils and favors old grassland, meadows, and heathland, but is also found in sparse woodlands, forest rides, prairies, parks, lawns, and roadside verges. In many areas, it is the most abundant species of ''

'' ant and the first to recolonize restored grassland.

Behaviour

The nest of ''F. incerta'' is excavated below ground and consists of one or more large chambers near the surface from which descend one or several vertical galleries about in diameter and up to long. The chambers in which the ants live radiate off these and typically measure , each having a level floor and domed roof. No mound is seen on the surface above the nest, but a newly excavated entrance may be surrounded by a halo of ejected soil. The entrance is inconspicuous and up to in diameter. Occasionally, two entrances to the nest are seen. A nest harbors several thousand ants and the eggs, larvae, and pupae. The largest colonies excavated in a Michigan study had several queens, a small number of winged females and developing reproductives, a few dozen immature workers, 2,000 mature workers, 2,000 pupae, 1,500 larvae, and a similar number of eggs. Some of the late-season larvae overwinter and augment the early-season workforce in the following year. The worker ants emerge from the nest to forage during the day. Newly mated queens likely join an existing colony of the same species and new colonies are founded when workers dig a new nest near the original one, carry some of the brood across, and guide a queen to the new nest. ''Formica incerta'' has a varied diet, and workers forage for nectar produced by

on such plants as

sunflower The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage (as a meal or a silage plant), as ...

s and

partridge pea ''Chamaecrista fasciculata'', the partridge pea, is a species of legume native to most of the eastern United States. It is an annual which grows to approximately 0.5 meters tall. It has bright yellow flowers from early summer until first frost ...

s. They also gather the honeydew from aphids and treehoppers and defend these food sources from non-nestmates, from ants of other species, and from

parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

s. In regions where larger ant species are numerous, they may be more furtive in their food-gathering behavior. On bare pastures, they are heavily preyed upon by

northern flicker The northern flicker or common flicker (''Colaptes auratus'') is a medium-sized bird of the woodpecker family. It is native to most of North America, parts of Central America, Cuba, and the Cayman Islands, and is one of the few woodpecker spec ...

s (''Colaptes auratus''). They are also the main target species for raids by the

'' Polyergus lucidus'', which steals the pupae and late-stage larvae.

References

External links

* {{Taxonbar, from=Q3651098 incerta Insects described in 1893 Hymenoptera of North America