Japanese Beetle

• In Japan it is an unobtrusive insect kept in check by its natural enemies; it reached the United States around 1916 in a consignment of bulbs and became a devastating pest there.
• It feeds in groups because the beetles already feeding release compounds that attract more of their kind, so that a plant can be covered in beetles within hours.
• It has entered Europe through northern Italy and Switzerland, and its advance is under plant health surveillance across the European Union.
• It reached the United States in 1916, detected in a New Jersey nursery, probably in the root ball of irises imported from Japan. Today it is found throughout the east of the country.
• In Japan it is an unobtrusive insect, kept in check by its natural enemies; outside Japan, without them, it becomes a pest.
• It is doubly harmful: the larva ruins lawns by eating roots from below, and the adult skeletonises leaves from above, leaving nothing but the veins.
• It feeds on more than three hundred plant species, from roses and grapevines to maples and apple trees.
• The adults aggregate in response to a pheromone and to the smell of damaged leaves, so damage attracts more damage and attacked plants become bait.
• It was detected in Italy in 2014 and in Switzerland in 2023, and it is one of the European Union's priority pests: its arrival in Spain is an active risk.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat & environment

Grasslands, gardens and crops; the larva lives in the soil eating grass roots, and the adult devours the leaves, flowers and fruit of more than three hundred plant species

Sources consulted: https://es.wikipedia.org/wiki/Popillia_japonica

Best time: From June to August, when the adults feed in numbers