A nationwide pest risk analysis in the context of the ongoing Japanese beetle invasion in Continental Europe: The case of metropolitan France

Abstract

The Japanese beetle, Popillia japonica, is native to Japan and became established in North America in the early twentieth century. The beetle was detected in Europe, first in Italy in 2014 and then in Switzerland in 2017. Metropolitan France is at the forefront of the Japanese beetle threat, due to its geographical proximity to the European populations established in the Piedmont, Lombardy and Ticino regions. An express pest risk analysis for metropolitan France was therefore conducted. The most likely pathways for entry include (i) natural dispersion, (ii) trades of plant products with adherent soil and (iii) hitchhiking behaviour, leading to a high probability of entry. The spread rate of P. japonica was also evaluated as high, resulting from natural spread as well as human activities. Given the absence of significant limiting factors, the potential impacts of P. japonica in France will likely be as important as in its current geographic distribution. Although several sources of uncertainty were highlighted throughout the evaluation, none of them has significant impact on the conclusions of the present express pest risk analysis. Measures to prevent entry, establishment and spread of P. japonica are recommended and include surveillance with pheromone traps and control via integrated pest management strategies. However, most efforts should be concentrated on eradication measures while P. japonica is still in the early stages of invasion.

A new chapter of the Japanese beetle invasion saga: predicting suitability from long-invaded areas to inform surveillance strategies in Europe

“…Other interceptions have been observed in Central Europe, while stable populations are only found in the Italian regions of Lombardy and Piedmont and the Ticino region in Switzerland (Poggi et al, 2022).…”

Popillia japonica – Italian outbreak management

“…The Plant Health authorities of the Lombardy and Piedmont regions reacted promptly, and several phytosanitary measures were adopted to monitor the area and to contain the P. japonica populations. Visual inspections and control measures were focused on all high-risk sites, e.g., plant nurseries and sites suitable for passive dispersal, such as industrial areas, trucking companies, railway stations, sports fields, playgrounds, boulevards, waste collection areas, petrol stations, car and truck parking areas, swimming pools, and shopping centers, considering the hitchhiking behavior of P. japonica adults ( 5 , 18 ). Control measures were performed in the infested area to suppress adult populations of P. japonica by installing several double-baited traps that attract both sexes using a floral attractant and a synthetic pheromone: i) funnel traps for mass trapping, ii) traps for auto-dissemination of the fungus Metarhizium anisopliae (Metch.)…”