Killer ants occupy Europe

Always more present the colonies of Lasius neglectus: conquer territories and excludes local wildlife.

MILAN - Has already invaded Warsaw, Geneva and the town of Jena in Germany: the new and more aggressive specie of garden ants, Lasius neglectus, most likely Asiatic, is slowly colonizing parks and gardens of half of Europe destroying the native species in their environment. Silent invasion, an excellent example of that phenomenon called "bioinvasion, which increasingly worries biologists and ethologists.

DOMAIN – Despite the similarity to the common black garden ants, Lasius neglectus have a very different social structure. In fact the queens leave the colony to establish a new one, but will copulate only with the males of their colony of origin, expanding it and increasing enormously the number of ants that dig into the soil to build new nests, until the area is not populated with a sort of "super colony." Once settled in a place, is able to impose itself without big efforts on other species, dominating the entire local fauna. These ants prosper in urban environments rather than in natural habitats.

RESISTANCE – This are pest colonies that contain between 10 and 100 times more ants than it would if it was occupied by native ants, as stated in a study published in the scientific journal " PLoS One”. The Lasius neglectus is omnivorous and adapts very well to the new environment. This Eurasian ant has arrived thanks man action. It was discovered in 1990 in Hungary. Then transported across Europe when they infest large potted plants which are then moved around across borders, their colonies are now present in over one hundred locations including France, Germany, Poland and Belgium, reports Sylvia Cremer, University of Regensburg in Germany, one of the authors of the study. Experts are convinced that it is only a matter of time: pitiless, fast and almost invisible the invasive ant will quickly colonize all Europe, up to Scandinavia, causing serious damage. This ant is resistant even at low temperatures, up to 5 degrees below zero.

ALERT - The spread of colonies across the continent, experts conjecture, occurs through garden centers but also unwittingly helped by "exchanges" offered during the fairs of gardening. "Ants are among the most important detritus eaters on the planet and by their actions help spare cycles. But there is a strong alarm among ethologists for these numerous and rapid changes in the composition of animals in our ecosystems, "says Enrico Alleva, president of the Italian Society of Ethology, which brings together researchers who are dedicated to the study of animal behavior and its biological basis. Just think that the fire ant (Solenopsis invicta), appeared for the first time in Alabama in the United States in 1930 - from where it spread rapidly in all states - every year estimated damage at is of around 600 million euros.

UNUSUAL - "It is probable that many ant infestations have already occurred, but which have not been identified due to the normal latency period that characterizes the invasive species first of the settlement," states Cremer. For the experts, is another shift in living organisms from one region to another and from an ecosystem to another, with a frequency and a speed that the planet had ever known. "So far, only people living in warmer areas of the planet had to deal with these parasites”, emphasizes Cremer, adding:" the presence of Lasius neglectus in Central and Southeast Europe is therefore quite unusual. "

Elmar Burchia
04 December 2008