Update of the situation of Popillia japonica in Switzerland
In Switzerland, Popillia japonica (Coleoptera: Scarabaeidae - EPPO A2 List) was found for the first time in June 2017 in Ticino, close to the outbreak area in Italy (EPPO RS 2017/160, RS 2019/157, RS 2020/167). In this canton, containment measures are being applied (RS 2021/104), and a country wide trapping network has been established to detect the possible presence of the beetle in other areas of Switzerland. In the canton of Ticino, the infested area has increased by about 10 km since 2021. Official phytosanitary measures include mass trapping, insecticide treatments, restrictions on the movement of soil (e.g. from construction sites), restrictions on the movement of rooted plants with soil, and of cut greenery, raising public awareness, intensive monitoring in the buffer zone.
As a result of the monitoring conducted in July and August 2023, two new outbreaks have been detected and official measures are being applied in the demarcated areas:
- in the canton of Valais, close to the Italian border;
- in Kloten, in the canton of Zürich close to the airport of Zürich. The population is considered very small and is concentrated in a residential area. This is the first report north of the Alps.
In addition, adult specimens were caught in pheromone traps in 3 cantons:
- One female in canton Graubünden (Eastern Switzerland).
- One male in canton Solothurn (Northern Switzerland, 2.3 km from a trap where one beetle had been caught in 2022).
- Two single beetles in Nordwestschweiz region (1.1 km from a trap where one beetle had been caught in 2021).
In all 3 cases, surveillance will be intensified in the areas concerned. It is assumed that these isolated beetles were transported there as hitch-hikers from the existing outbreaks.
The pest status of Popillia japonica in Switzerland is officially declared as: Present, only in some parts of the country, under containment in case eradication is impossible.
Sources
NPPO of Switzerland (2023-08).
Anonymous (2023) Décision de portée générale sur les mesures d’urgence visant à prévenir la propagation de Popillia japonica Newman dans le canton du Tessin https://www.fedlex.admin.ch/eli/fga/2023/220/fr