Warning over devastating Japanese beetle found close to French border
Authorities ban transporting plants in a bid to curb their spread
Whenever the Japanese beetle arrives in a new country it ravages the native plants due to the absence of natural predators
Susan Hodgson/Shutterstock
Authorities in France are warning people to be on the lookout for the Japanese beetle, an invasive type of scarab that devours up to 400 varieties of plant, after it was detected just a few kilometres away across the Swiss border.
In its native Japan, the beetle is not considered to be a pest due to the presence of natural predators: tachinid flies and assassin bugs, as well as spiders and birds.
However, when it arrives in a new country the beetle ravages the native plants, including plum, apple, grapevine, maize, soy, beans, asparagus, forests and lawns.
This was the case when it arrived in the United States in 1916, in Italy in 2014 and in Switzerland in 2017.
On June 20, the beetle was detected near Basel - only 3.5km from the French border.
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‘No way to stop it reaching France’
France’s public health agency ANSES has been preparing for the beetle’s arrival in France for several years and says it is inevitable.
"According to the results of our expert appraisal, there is nothing to stop it becoming established in France,” Christine Tayeh from the ANSES Plant Health Laboratory told the agency’s website in 2022.
“It is an insect that moves around easily, the temperature and precipitation conditions here are favourable, and it will have no difficulty finding sources of food because it can feed on many of the plant species found in France."
The agency hopes to identify the inevitable population clusters in France via “dynamic surveillance” and stop them before they can spread.
“This is how it was eradicated from Oregon and California," said Ms Tayeh.
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Ban on transporting plants
Since the bug’s arrival near the border in June, the authorities have stepped up their surveillance efforts.
A total of 39 traps equipped with combination lures (with both sex pheromones and floral attractants) have been set up at train stations, customs checkpoints, airports and motorway service stations, throughout Alsace (Grand-Est).
The commune of Saint-Louis, which neighbours Basel, has been given particular attention, with traps positioned “every kilometre”, according to the departmental prefecture.
The prefecture has also banned the transportation of "soil, plants rooted in soil, rolls of pre-cultivated grass, plant debris and compost" in the communes of Hégenheim, Hésingue, Huningue, Saint-Louis and Village-Neuf.
Anyone who spots a Japanese beetle in France is asked to report it to the authorities, here, or by calling 03 39 59 40 95.
