The Tapinoma magnum ant is only 4mm long, but its large colonies are wreaking havoc | ULI DECK/DPA/ALAMY LIVE NEWS
A destructive species of ant is spreading through Germany faster than expected, with scientists warning that the proliferation of insects may be unstoppable.
The discovery of the Tapinoma magnum ant started with innocuous-seeming plants at garden centres in Coswig and Dresden, in the far east of the country. But when the biologist Bernhard Seifert peered into the soil, he found traces of what is now considered one of Germany’s most destructive invasive species.
The tiny species, measuring barely 4mm, was once confined largely to the warmer climates of the Mediterranean area. It has been found to have settled early on in Italy, either naturally or through the flourishing trade between Ancient Rome and its “breadbasket” in northern Africa. Lately, it has been settling in Germany’s southwest and Rhineland areas.
The insects first wreaked havoc in places such as Kehl, near the French border. The city reported damage to public infrastructure, and cuts to power and the internet, caused by the ants.
Seifert’s discovery suggests that the species is spreading rapidly throughout Germany, said Manfred Verhaagh, one of the scientists behind a Tapinoma research project at the Natural History Museums of Karlsruhe and Stuttgart. He said that he was receiving reports of the ants from new places every week.
The ants have also been found in ten European countries, including France, Belgium, the UK and even Azerbaijan. Verhaagh noted, however, that Germany appeared to be a stronghold, possibly because of the growing interest in potted plants from the Mediterranean area, which have become more popular as Germany’s winters get milder.
The ants penetrate cavities in buildings and infiltrate electrical boxes, using cables to move into the spaces, which caused the power cuts in Kehl. In Karlsruhe, the city’s suburban railway is struggling with loose pavements near the platforms, undermined by ant colonies.
In Marlen, a suburb of Kehl, a children’s playground had to be closed after the ground began to buckle under the sheer number of ants tunnelling beneath it. There is also a psychological cost as the animals settle in private gardens, where they leave bite marks on their hosts’ limbs, invade their homes and lead to a proliferation of plant lice, whose manure serves as nutrition for the ants.
“Some people don’t even dare to go on holiday any more as they fear that the ants will move into their home in their absence,” Verhaagh said. Biologists warn that the species’ spread may be unstoppable in their new habitat, lacking the natural enemies of their previous environments.
Prompted by requests on how to get rid of the ants, Verhaagh has spent “hours” researching a way to defeat them. “I’ve found almost nothing,” he said, adding that aggressive pesticides are often forbidden in Germany and may fuel the growing decline in all insects.
Municipal teams in cities such as Tübingen and Kehl now deploy boiling water at 95°C into the soil to avoid chemicals. But Tapinoma magnum is also known to be able to weather extreme temperatures by retreating further into the ground, where it can survive temperatures below minus 10C.