Invasive fire ants make landfall in Europe

What problems could they bring to the native ecosystem?
15 September 2023

Interview with 

Mattia Menchetti, Instituto de Biología Evolutiva


A fire ant


Invasive and non native species play havoc with ecosystems and economies worldwide. In the UK alone, invasive are thought to cost us 4 billion pounds a year, because of things like forestry and agriculture. Therefore, keeping an eye on which organisms are entering where is a very important job. And there has now been some troubling news coming out of Sicily, as Will Tingle takes up the story...

Will - The red fire ant, Solenopsis invicta, is the fifth most costly invasive species in the world, costing global economies nearly $6 billion a year. Originating in South America, it has been on a colonising rampage across almost every continent for the past hundred years, save for Africa and Europe. But now that has changed as scientists have confirmed 88 nests on the small island of Syracuse in Sicily. I spoke to the Institute of Evolutionary Biology's Mattia Manchetti, about how far we think the ants have currently spread.

Mattia - So it's hard to say. For now we know that they are Sicily and they are in this spot and we don't really know the real extension. What we know is that this species has been there for at least probably four years, maybe even more. And this probably is not the first site of introduction because it's a very small marina. So it couldn't arrive there, it's impossible, or let's say it's unlikely that it arrived from the US or China. So that has to be somewhere, a place where it arrived first, maybe a big harbour or an airport. We don't know yet. So this is what we'll need to find out.

Will - The implication, therefore, is that these ants probably entered Europe somewhere else and made a separate journey to this island. Wherever that original point of access was, remains to be seen. But regardless, four years is seemingly a long time for these ants to exist and go relatively unnoticed on the island.

Mattia - Yes. And then maybe it can be even more, I would say. So we don't really know. Also the area can be much larger. It's hard to find such a small insect. They create big colonies, but there are not so many ant specialists in Europe. For the general public, these are just ants. Maybe they're more painful when they sting.

Will - And that sting is no joke. In fact, it is so potent. It can cause some children to go into anaphylactic shock. That's bad enough, but the problems don't end there.

Mattia - They cause a strong decline of general biodiversity of insects, invertebrates in general and even small vertebrates. And then we also had the economic problem of the species. They can damage electrical equipment, for example. Agricultural losses there are due to the presence of the species.

Will - These ants then cause medical, environmental, and economic havoc outside of their original habitat. So eradicating invasives is a notoriously difficult task. Just ask Florida about their Burmese pythons. So what is the plan to deal with these ants?

Mattia - This could be the next step for sure, trying to eradicate them, but it's gonna be very, very difficult to eradicate them. First because we don't know actually what is the real expansion of the embedded area. So this is, I think, the first step, understanding where they are and then the local authorities will try to eradicate them and then we'll see what is going to happen. Because there is long experience over eradication of the species and it's mostly come down to control. It's very hard to eradicate the species. New Zealand managed it three times actually, but it really will depend on the extension of the embedded area.

Will - New Zealand shows that there is hope, but this plan needs to start sooner rather than later because, as Southern Europe can surely attest after this summer, the temperature is rising. And the fire end favours the heat.

Mattia - Yes. So climate change is definitely helping new species, new alien species, to establish. It seems that climate change will definitely favour the Solenopsis invicta. So this is another aspect we have to keep in consideration when we are talking about climate change. Not only the direct impact, but what it favours. In this case, it may favour the establishment of the species in places where now it's not suitable.


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