The Japanese beetle, a pest long established in the United States, has become an increasing problem for European agriculture following its initial discovery near Milan’s Malpensa airport. The iridescent green insects have established populations across several northern Italian regions including Lombardy, Piedmont, and Valle d’Aosta, where they were first documented in terraced vineyards last year.
These beetles damage crops by consuming leaf tissue in characteristic patterns that weaken plants and reduce their productivity. With a diet encompassing over 300 different plant and tree species, the Japanese beetle feeds voraciously and travels in large groups while also hitching rides on vehicles and aircraft. The insects can devastate harvests outright in some areas, though their primary impact often involves reducing plant vigor and preventing proper ripening of fruits and grapes through defoliation.
The European Union has classified the Japanese beetle as a priority pest, prompting coordinated control efforts. However, the situation varies by country. The pest is already well-established in Italy, Switzerland, and Germany, where management and containment have become the focus, while populations in France and Spain remain at levels where eradication may still be possible. The beetle’s lifecycle, which includes larvae feeding on grass roots over winter months before emerging as adults, complicates control strategies.
Agricultural organizations have warned that the advancing beetle population poses a major threat to productivity across the Po River Valley, Italy’s primary agricultural region. Scientists are exploring various control methods, including introducing microscopic parasites to target beetle larvae, using pheromone traps, and applying pesticides. However, experts caution that without effective intervention, beetle populations will continue expanding, resulting in substantial damage to fruit production, vineyards, and ornamental plants across the continent.