Invasive Japanese beetle threatens vineyards and orchards in northern Italy

Iridescent green Japanese beetles native to Japan are swarming vineyards and orchards in northern Italy, chewing through leaves and leaving the lattice-like damage that weakens plants and cuts production. In Pont-Saint-Martin, in the Valle d’Aosta region, beetles were photographed on vine leaves on July 9.

Popillia japonica feeds on a wide range of plants, including fruit trees and ornamental plantings, which gives it more places to survive and more chances to spread from one property to the next. The risk extends to orchards, village plantings and the higher-value crops that support regional food production and exports.

For growers already dealing with weather volatility, labor shortages and higher input costs, the beetle is another pressure on margins. Its feeding scars reduce the leaf surface plants need to make energy, and its ability to move quickly through contiguous plantings means one untreated orchard or vineyard can keep the infestation alive. Northern Italy’s fertile agricultural belt gives the pest abundant food sources.

Containment depends on sustained monitoring and treatment. Farmers use traps, targeted pesticide applications and canopy management, but those methods work best when neighboring properties act together. The insect does not respect farm boundaries, so gaps in treatment can allow it to keep moving.

A Frontiers in Insect Science review published May 18, 2023 examined Italian outbreak management. A separate June 14, 2023 study focused on the private management costs of Popillia japonica in Italian viticulture. A 2024 NeoBiota paper on the beetle’s spread in Europe linked human-mediated transport to movement beyond its original foothold.