“The Tapinoma Magnum ant makes everyday life difficult”

• A Mediterranean ant has invaded the gardens and homes of 200 households in Saumur, where it is causing "strong inconvenience".

• This species, called Tapinoma Magnum, will be difficult to eradicate and risks on the contrary proliferating in other municipalities in the West, as already noted by Loïc Bidault, elected official in ecology and vice-president of the Conservatory of natural spaces. Pays-de-la-Loire.

In recent years, ants of a new kind have been ruining the lives of around 200 homes in a district of the city of Saumur (Maine-et-Loire).

This invasive alien species, called

, proliferated again this summer, thanks to the high temperatures.

Who are these insects and can we overcome them?

The point with a specialist, Loïc Bidault, elected in ecology, sustainable development and energy transition at the city of Saumur who also holds the position of vice-president of the Conservatory of natural spaces of Pays-de-la- Loire.

Can you introduce us to the

It is a Mediterranean species, Corsican more precisely, which then arrived in the south of France.

It has now been with us, in Saumur, for three to six years, but we really identified it last year, following protests from the inhabitants and with the help of scientists from the Institute for Research on insect biology (Irbi) from Tours.

It is thought to have arrived via the transport of ornamental plants, often surrounded by clods of earth, perhaps with the fashion for olive or palm trees which arrive from around the Mediterranean.

Scientists also make the link with global warming because they find environments with us that are welcoming.

It is a species with a very particular behavior, very invasive, and which brings strong inconveniences.

That's to say ?

ant

lives in super colonies.

They spread particularly quickly, without any competition with other anthills.

We can recognize them with the naked eye because they are very small and have an extremely gregarious, hyperactive behavior.

They are mainly found on degraded land, cuttings.

But they are also there in large numbers in the gardens: it's teeming everywhere and if you step outside, they climb on you.

A lady confided to me that because of this, her grandchildren no longer came to her house in the summer!

They do not bite but have a very invasive side.

Another peculiarity, they give off a smell of rancid butter when they are crushed…

And they also do damage...

Yes, especially in vegetable gardens, we have seen courgettes or young tree seedlings completely attacked.

In fact, these species which have no predators create a vacuum around them: in the sectors where the

thrives, our classic ant risks disappearing in the coming years.

Thanks to the pipes, cables, they are also introduced into the houses… We had electric meters which jumped in some inhabitants!

This makes daily life difficult for some of those concerned.

Last year, it took on a considerable scale, people were completely helpless so we had to propose a scientific and framed approach, with a lot of education.

What can we do about these ants?

As soon as the species is identified, it must be treated immediately.

What we could not do quickly enough here, with now an 18-hectare district concerned, and an appearance of these ants in two cemeteries as well.

Scientists tell us that we will not be able to eradicate it so we contain, we limit as much as possible.

We have voted financial aid over three years to carry out three treatments per year in the individuals concerned.

As for public spaces, we treat every 15 days from March to September with a product based on spinosad that can be used organically.

The results are quite positive.

The

" 

 "

Saumur acts as a laboratory for the whole of France and I regularly have municipalities call me to ask me how we go about it.

It is therefore clear that we are going to talk about this ant again, here but also elsewhere, and in particular in the Loire Valley or in Loire-Atlantique, where it has been identified for example in Ancenis.

We will see how the species evolves, there may be surprises.

Near Pau, there is a village where the ant disappeared in one summer, for no reason... Fingers crossed that it happens to us!

There is also the possibility of another invasive species arriving and dislodging this one.

In the meantime, the drop in temperatures should offer us a period of calm, until March.

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