Destructive Japanese scarab beetle gains ground in France
Sightings of Popillia japonica should be reported. It was recently seen in the Bas-Rhin, Alpes-Maritimes and Bourgogne-Franche-Comté
French authorities have stepped up surveillance after fresh detections of an invasive Japanese beetle in different parts of the country, with researchers warning that the pest's establishment may ultimately be impossible to prevent.
The insect, Popillia japonica, has been found this summer in the Bas-Rhin, Alpes-Maritimes and Bourgogne-Franche-Comté. It was first detected in France in 2025.
Although no breeding population has yet been confirmed, the repeated discoveries have prompted an expansion of trapping and monitoring programmes in regions considered most at risk.
Serious threat to crops
The Japanese scarab beetle is listed by the European Union as a priority quarantine pest because of the damage it can cause to agriculture, horticulture and the environment.
Adult beetles feed on the leaves, flowers and fruit of more than 300 plant species, including vines, apple trees, maize, soybeans and roses. Their larvae develop underground, feeding on roots and damaging lawns, sports pitches and pasture.
Researchers say the greatest economic impact could be on vineyards and orchards.
A 2022 study by the Technical University of Munich estimated that, without control measures, the pest could cost Europe between €30million and €7.8billion a year depending on the scale of the invasion.
France was identified as the country facing the highest potential losses, particularly for its wine industry.
The beetle is around 1cm long, with a metallic green thorax, copper-brown wing cases and distinctive white tufts of hair along each side of its abdomen.
'Its establishment is inevitable'
Originally from eastern Asia, the beetle became established in northern Italy in 2014 and Switzerland in 2017. Scientists say its spread into France has long been expected.
"Its establishment is inevitable. We will not stop it," Jean-Claude Streito, a researcher at France's Inrae agricultural research institute, told Le Monde.
Other specialists are more cautious, stressing that detecting individual insects does not necessarily mean permanent populations have become established.
Researchers also reject suggestions that climate change is responsible for its arrival, saying international trade and transport are the main drivers.
The beetle is known as a ‘hitchhiker’ because it can travel long distances hidden in vehicles, luggage and freight.
Hundreds of traps deployed
France has had a national emergency response plan in place for several years and has expanded surveillance this summer.
Around 180 traps have been deployed in the Grand Est region, including 130 in Alsace. Provence-Alpes-Côte d'Azur now has 177 traps after extra devices were installed following recent detections near Cannes and Mougins, while Bourgogne-Franche-Comté has around 120.
Traps are concentrated near motorways, railway lines, airports, campsites, logistics centres and other high-risk locations.
Anyone who believes they have found a Japanese beetle is asked to report it here or to their regional agriculture authority.
Rise in invasive species
The Japanese beetle is the latest in a growing list of invasive species causing concern in France.
Authorities are already battling pests including Asian hornets, electric ants and tiger mosquitoes, while biodiversity agencies are monitoring species such as common snapping turtles and invasive plants including white skunk cabbage.
Earlier this year France also called for closer EU co-ordination on tackling invasive species, arguing that faster cross-border action offers the best chance of preventing newly arrived species from becoming permanently established.
