Invasive ant species also in Offenbach: joint control necessary

"Ants don't stick to property boundaries, which is why we are inviting property owners in the Bürgel distribution area to an information evening in the next few days," says city treasurer and responsible department head Martin Wilhelm. Those affected will be personally invited to this evening, which will be attended by a pest controller who has experience with this type of ant, the head of department and representatives of the municipal utility company. "We would like to encourage property owners to join us in a coordinated effort to hire an expert to combat Tapinoma Magnum. As outlined in the report, we as a city in public spaces and the owners of private properties must act in a coordinated and simultaneous manner if we want to successfully combat these ants."

Tapinoma magnum is not dangerous to humans. Their presence is mainly problematic because they can form so-called super-colonies over large areas with millions of individuals. Unlike native species, several egg-laying queens live in the nests, which ensure exponential growth of Tapinoma magnum. It is therefore important to destroy the nests to prevent the population from growing back. When the workers of the colony excavate their nests and tunnels, this becomes visible on sidewalks in the form of large piles of sand. They also form large walkways, so-called roads. The animals are harmful because they destroy the infrastructure by burrowing under terraces, driveways, sidewalks or roads and also enter houses in search of food.

In the report on the spread in Bürgel, the expert speaks of such a super-colony, which probably consists of several million individuals. His report also contains information about the habits of the animals, which were probably introduced from the Mediterranean in the soil of an oleander or lemon tree. They particularly like surfaces that heat up quickly. These are, for example, paved surfaces such as sidewalks or terraces, but also gravel gardens: It gets warm in the nests underneath and so the brood develops well. Wherever possible, areas should ideally be planted with tall grasses and shrubs. Ground cover plants are also recommended.

The pest controller commissioned by ESO Eigenbetrieb kommunale Dienstleistungen advises against blindly tackling every anthill in your garden with hot water or chemicals out of panic. Because where native species occupy the soil, Tapinoma magnum has a harder time spreading.

And how can you tell the difference between Tapinoma magnum and a normal native ant that should not be controlled? First of all, the invasive species forms much wider roads than paths. Often several animals walk side by side, whereas native species tend to crawl one behind the other. Tapinoma magnum is also larger, although there can also be noticeable differences in the size of individuals within a colony. Overall, there are significantly more ants visible than in local species.

And two colleagues from Stadtservice, who have already attended a training course on the invasive species, have brought back another test from there: a crushed Tapinoma magnum emits a pungent chemical odor, which some describe as smoky and reminds others of acetone. Anyone who has reasonable grounds to suspect sightings of this invasive species can contact the Stadtservice's customer service department on 069/840004-545.