Popillia JAPONICA

HISTORY AND PEST STATUS

Popillia japonica Newman (Coleoptera Rutelidae) is an invasive species native to Japan. In 1916, the insect was accidentally introduced to the United States and was able to invade large areas of northern America and southern Canada. Until a few years ago, the presence of Popillia japonica in Europe was recorded only in the Azores Islands (Portugal). In the summer of 2014, adult individuals of Popillia japonica were recorded in continental Europe, in some municipalities in the northern area of the Ticino Valley, between Lombardy and Piedmont (Northern Italy).

Due to the enormous economic damage it can cause, Popillia japonica is considered a quarantine pest by phytosanitary legislation in the EU.

HOW TO RECOGNIZE IT

The adults are about 10 mm in length, their body is metallic green with bronze reflections on the wing covers. They are characterised by 12 patches of white hair (5 on the sides of the abdomen and 2 wider ones on the terminal part of the abdomen).

The presence of these white patches allows to unmistakably distinguish Popillia japonica from the Italian species of garden beetles (Phyllopertha horticola) and from other species of Italian rutelids.

BIOLOGICAL CYCLE

In the Lombardy region, Popillia japonica completes one generation a year. The adults start to emerge from the ground between the end of May and the beginning of June. Males appear a few days earlier than females. The females lay their eggs under the turf.

The insect moves mainly in large groups and the period of greatest presence of P. japonica adults is around the month of July.

FOOD PREFERENCES AND DAMAGE

The larval stage primarily infests hay meadows, pastures and lawns and feeds on grass roots. The adults are polyphagous and cause damage on foliage and flowers of spontaneous, open field, ornamental and forest plants.

Adults can feed on nearly 300 host species, but the most serious damages are recorded on a limited number of plants. Among the most affected are: maple, wisteria, rose, bramble, linden, elm, corn, apple, peach, soy and vine.

WHAT TO DO

In case of sighting, you should:

  • Identify the species by checking the presence of patches of white hair on the sides of the abdomen;

  • Remove and eliminate the insects (take a picture of the insects first, if possible);

  • Observe the infested plant and, if possible, try to identify the activity of the species (e.g. feeding or reproductive activity);

  • Make a report to the address: popillia@ersaf.lombardia.it

Information leaflet by the Lombardy Regional Phytosanitary Service, further information (only in Italian) available at: https://bit.ly/2SfYwUx

Popillia Japonica has been added to the FitoDetective App created by the Lombardy Regional Phytosanitary Service. Get the Free app here.

Through the APP you can:

  1. Receive information and news relating to invasive alien species;

  2. Report a suspected sighting.