Poisonous Asian needle ants arrive in Europe and could ‘threaten ecosystems’

Academics have confirmed the presence in Europe of an invasive ant species that can cause biodiversity loss and severe allergic reactions.

The Asian needle ant, or the Brachyponera chinensis, is primarily found in coastal regions of China, Taiwan, the Korean peninsula, and Japan.

But, over the last 90 years, the poisonous species has spread to 17 states in the US, mainly on the east coast, and also – most recently – to Europe.

This is according to Spanish research team led by the Institute of Evolutionary Biology (IBE) in Barcelona, which said that B. chinensis “invades” forest habitats and has had a “strong negative effect on most native ant species”.

Its poisonous bite can cause serious allergic reasons and, for this reason, the ant has been identified as an emerging public health threat in the US, the scientists said, where it was introduced from Japan in the early 1930s.

Vincenzo Gentile, an author of the study and an amateur entomologist found a male ant of an “unidentified” species that was attracted to the light of a street lamp in a residential area of Naples, Italy, in July 2020 – which was then identified as an Asian needle ant.

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The ant underwent genetic analysis, which confirmed that it was of the B. chinensis species. It may have made it to Italy from the US, or the species could have been introduced to Europe and North America from the same place of origin, the study suggests.

Predoctoral researcher Mattia Menchetti carried out the genetic analysis at the Butterfly Diversity and Evolution Laboratory at the IBE, led by principal investigator Roger Vila.

Mr Vila said: “This is an invasive species that is causing significant ecological and health problems in the United States and could have effects in Europe comparable to those of the Asian hornet or the Argentine ant.

“Experience tells us that, once the exponential phase of expansion of an invasive species has been reached, we do not have the means to eradicate it and at most, we can control it by investing huge amounts of public resources.

“Therefore, it is necessary to take advantage of the window of opportunity posed by the so-called latency phase: the time during which the invasive species becomes established in the new place and is still very localized.

“We must rethink the strategy of controlling invasive species and redirect resources towards biomonitoring, which will allow early detection, and the deployment of a rapid response team as soon as the alarm of a new introduction sounds.”

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It’s believed that the ant species was introduced to other continents as a result of globalisation and specifically the plant trade. Insects’ introductions to people’s gardens slows the detection of these species in their early stages, the researchers said.

The expansion of B. chinensis in North American forest habitats suggests that it could invade European natural habitats, forests in particular, the study says. This could lead to negative effects on native ant communities and the health of the ecosystems, the researchers said.

It’s highly likely Naples could have at least one colony of the ants, Mr Menchetti suggested, as the tested ant was flying and in the process of swarming when it was captured.

The nest, or nests, could be in “difficult-to-access private areas” and this could enable them to “propagate without being detected,” he said.

Mr Menchetti added: “Neither can it be ruled out that a colony without queens has been introduced and that the males have been produced by worker ants, which is exceptional but possible for [the species].”

He also called for a detailed survey of a “large area around Torre Annunziata” to establish the extent of injuries the ants may have caused with their poisonous bite.