Ant supercolony

[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 Argentine ant (Linepithema humile), forming megacolonies of spatially separate nests, was thought to be a perfect example of unicoloniality, never exhibiting multicoloniality.

[8] Giraud et al. (2002), however, discovered that L. humile also forms supercolonies that are aggressive to each other, so unicoloniality turned out to be limited.

[8] Therefore, Pedersen et al. (2006) redefined supercoloniality and unicoloniality as follows: They suggest that the success of invasive ants such as L. humile stem from the ecological conditions in the introduced range that allow to dramatically extend the dimension of supercolonies, rather than from a shift in social organization in the invaded habitat.

They can cover tens of kilometers, number hundreds of thousands or millions of individuals and show lack of intercolony aggression.

[12] The Ishikari supercolony of Formica yessensis on Hokkaido, Japan comprise estimated more than 45,000 nests, more than 300,000,000 workers and more than 1,000,000 queens.

Invaded in urban areas, it exhibits extreme polygyny and polydomy and becomes a dominant invasive pest.

Large anthill in South Tyrol
Large trail of ants
Map of 33 European populations of Linepithema humile sampled. Populations were assigned to one of two distinct groups based on the aggression tests: the main supercolony (●) and the Catalonian supercolony (○). In the population marked with asterisk, workers were heavily infected with mites, which affected the behavioral interactions. Consequently, this population was not included in the analysis of behavioral data.