With the start of the summer holidays, the Federal Ministry of Agriculture, Food and Home (BMLEH) warns of the introduction of the Japanese beetle (Popillia japonica) to Germany. Travelers should especially avoid bringing plants, soil, seeds, or sod from northern Italy or southern Switzerland and should carefully check their luggage, car, and camping equipment before returning home. The beetle can travel unnoticed as a "stowaway" and poses a significant threat to viticulture.

The severity of the consequences of an infestation has been evident for years in northern Italy. After the Japanese beetle was first detected in 2014 in the Parco del Ticino between Lombardy and Piedmont, it has spread to areas including Piedmont and, since 2022, also in the Aosta Valley. The wine-growing regions around Donnas and Pont-Saint-Martin are particularly affected. Winemakers report of defoliated vines, unprotected grapes with sunburn damage, and significant yield losses. The combination of drought and massive leaf feeding further stresses the vines.

The extent of the spread is also causing concern for authorities. According to Italian plant protection services, the number of beetles caught in monitoring traps has multiplied within a few years. In one monitoring area alone, the number of registered specimens increased from around 500 to more than 26,000. Despite an extensive network of lure and monitoring traps, these measures are primarily aimed at containment – complete eradication of the pest is hardly possible in larger infestation areas.

The Japanese beetle is only eight to eleven millimeters in size but is considered one of the most significant invasive plant pests. Its larvae feed on roots in the soil, while the adult beetles damage leaves, flowers, and fruits of more than 300 plant species. A typical feeding pattern is called skeletonization, where only the leaf veins remain. Important host plants include grapevines, apple and pear trees, stone fruits, berries, corn, asparagus, maple, and roses.

Germany is currently largely free of the Japanese beetle. Individual suspected cases can be reported to the respective plant protection service of the federal states – preferably with a photo or a securely packaged beetle. The Japanese beetle is classified as an EU quarantine pest and is among the priority harmful organisms whose introduction and spread in Europe should be prevented.

(ru – Image: Wikipedia)