A new ant which was discovered less than 20 years ago could be on the way to wreak havoc in parks and gardens of Northern Europe including Britain, according to a report published today.
The invasive pest ant Lasius neglectus has been found in more than 100 locations across Europe, where it quickly exterminates its local rivals, the study says.
It resembles the common black garden ant but the number of workers crawling around is between 10 and 100 times greater.
An international team of 20 researchers, co-ordinated from the Centre for Social Evolution at the University of Copenhagen, Denmark, started a study of the ants more than five years ago.
Dr Sylvia Cremer, lead author, said: "We found that invasive garden ants developed from species in the Black Sea region that have natural populations with small networks of interconnected nests with many queens that mate underground and don't fly.
"It is now becoming clear that rather many ant species share this lifestyle, so that it is no surprise that a number of them have become invasive pests with giant super-colonies based on the same principles."
As the ant's name illustrates, the species was overlooked until it was described in 1990, when it had already infested a neighbourhood in the Hungarian capital Budapest.
"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 Boomsma, one of its co-discoverers.
The ant is able to thrive in the temperate climate zones of Europe and Asia, and has now reached Jena in Germany, Ghent in Belgium, and Warsaw in Poland.
They can move to new areas when they infest large potted plants which are then moved around across borders.
"The future will see many more ants become invasive, so it is about time we understand their biology and this study is a major step in that direction," says Jes Pedersen, who co-ordinates the research programme in Copenhagen.
The study is published in the online, open-access journal PLoS ONE.