Japanese beetle, a serious pest of a wide range of ornamental plants through eastern USA, has been discovered for the first time in mainland Europe.
The beetle, Popillia japonica, is a small 1cm long insect that feeds on grass roots but also the foliage and flowers of many trees, and shrubs, and especially roses – 295 recorded species in all. It has been discovered close to two airports in northern Italy at Piedmont and Lombardy, feeding on both wild plants and nearby crops. A subsequent survey has found well-established beetle populations throughout the quarantined area.
Northern Italy has many of Europe’s largest nurseries, and plants move regularly throughout Europe’s member states. Many European countries, including those with large plant resellers like The Netherlands, have the right climatic conditions for the beetle to flourish and spread.
All European gardeners should be on the alert for Japanese beetle and report it to their local quarantine authority.
Popillia japonica is native to Japan where it is held in check by several predators. It arrived in the USA in the early 20th century before quarantine inspections became mandatory and has since spread throughout the eastern states and to Canada. It was discovered on the Azores Islands off the coast or Portugal in the 1980s where its spread was facilitated by extensive irrigated lawns which provide an ideal host site for the beetle’s larvae, which feeds on grass roots in moist soils. The adult beetles skeletonise leaves and also eat flowers on plants such as maples, roses, Prunus species, rhubarb, mulberry, Tilia (limes), elms and grape vines.
Identification: Japanese beetle has distinct white brushes along the side of its body, to distinguish it from other similar beetles. It is also inclined to swarm, reducing ornamental plants to a few scrappy leaves in a matter of hours.