Ant supercolony

An ant supercolony is an exceptionally large ant colony, consisting of a high number of spatially separated but socially connected nests of a single ant species (meaning that the colony is polydomous), spread over a large area without territorial borders. Supercolonies are typically polygynous, containing many egg-laying females (queens or gynes).^[1][2] Workers and queens from different nests within the same supercolony can freely move among the nests, and all workers cooperate indiscriminately with each other in collecting food and care of the brood, and show no apparent mutual aggressive behavior.^[3][4]

As long as suitable unoccupied space with sufficient resources is available, supercolonies expand continuously through budding, as queens together with some workers migrate over short distances and establish a new connected nest. The supercolony can also expand over long distances through jump-dispersal, potentially ranging between continents.^[2] Jump-dispersal usually occurs unintentionally through human-mediated transport. A striking example of an ant species forming supercolonies across continents is the Argentine ant (Linepithema humile). The also highly invasive red imported fire ant (Solenopsis invicta) and Solenopsis geminata additionally use classic mating flights, thus using three primary modes of dispersal.^[5][6] Out of some 14,000 described ant species, supercolonialism is found in less than 1% of all ants.^[2]

In general, ants that form supercolonies are invasive and harmful in the non-native environments.^[7] While not all supercolonial species are invasive and not all invasive ants are dominant, supercolonies are usually associated with invasive populations. Some invasive species are known to form supercolonies in their native habitat as well. In their native range, relatively small supercolonies are observed, whereas they are much larger, dominant and a threat for ecological diversity in their invasive range.^[4] Exceptions of species that form supercolonies without being invasive are mainly found in the genus Formica.^[2]

Although supercolonies are mainly observed in relatively few ant species, similar unicolonial populations are also found in some species of the termite genus Reticulitermes.