The ants are coming

3 December 2008

Lasius neglectus – it sounds quite innocent, but behind the Latin name is a very aggressive invasive garden ant, not unlike the Iberian (killer) slug in terms of the havoc it wrecks in parks and gardens. And there are more ant invasions like this to come.

Researchers from the Centre for Social Evolution at the University of Copenhagen have been keeping an eye on the small animal for quite some time. New studies now illuminate where the ant comes from and how it organises its supercolonies as well as shedding light on its capacity to spread and invade. The new research findings call for much closer monitoring of urban ecosystems to eliminate infestations before they become problematic.

– We found that the invasive garden ants developed from a number of species in the Black Sea region that have natural populations with entire networks of interconnected nests with many queens that mate underground and do not fly away afterwards, says Associate Professor Jes Søe Pedersen, Centre for Social Evolution.

The invasive garden ant (Lasius neglectus) was completely overlooked until it was described in 1990 following the discovery of a more than two-kilometre-long supercolony in Budapest, Hungary. Since then, it has been found in more than 100 locations across Europe, where it prefers parks and gardens and quickly exterminates the native ant fauna. And it does not stand back from moving into houses where it is a nuisance to people. It resembles the common black garden ant but the number of workers crawling around on the ground and on plants is some 10 times greater.

– When I saw this ant for the first time, I simply could not believe there could be so many garden ants in the same lawn, says Professor Jacobus J. Boomsma, one of the co-discoverers of the new species almost 20 years ago.