“We hope that this will help to contain the Japanese beetle,” said Simon Leuenberger, head of the department for the maintenance of green spaces in Switzerland’s third-largest city, about the new procedure. “But it will only be clear next year whether we are successful.” Soil samples will then be taken for monitoring purposes. The beetle has so far been found in twelve places in the region.
The nematodes penetrate Japanese beetle larvae and kill them, as the cantons of Basel-Stadt and Basel-Landschaft reported. The nematode strains are effective against Japanese beetle larvae as well as against the larvae of the black vine weevil and garden chafer pests. “The nematodes are harmless to other animals and humans.” The method now chosen on a total of around 38 hectares is complex, because the treated areas must be kept moist.
The animals eat more than 300 plant species
In the middle of the year, a population of Japanese beetles was discovered in the city. After the findings in Basel, the district of Lörrach on the German side of the Rhine expanded preventive protection measures. There is a so-called infestation zone there – plant material, for example, is to remain in place for the time being. As a spokesman now reported, the district of Lörrach was informed early on about the new procedure in Basel. Fortunately, the situation in the district has not changed since July – infestation and buffer zones therefore no longer needed to be expanded.
The Japanese beetle (Popillia japonica), which comes from Asia, is classified as a pest in the EU. The insect is a particular threat to viticulture, horticulture and agriculture. Roses, blackberries, grapes: the animals attack orchards, vineyards, forests, green spaces and gardens, devouring everything on more than 300 plant species.
In Ticino since 2017
According to earlier information, the Japanese beetle arrived in Ticino from Italy in 2017 and then in other regions of the Alpine country. In neighboring Baden-Württemberg, several specimens of the dangerous beetle species were caught this year – experts fear that the beetle was probably introduced via freight transport. A specimen was also discovered in Bavaria.
Concern about the invasive species is now so great in Germany that the Federal Ministry of Agriculture and the Julius Kühn Institute, the Federal Research Institute for Cultivated Plants, have also issued warnings.
Distinguishing features: White tufts of hair
The Japanese beetle is only about one centimeter long, has a shiny metallic green head and brown wings. It has five white tufts of hair on each side of the abdomen and two white tufts of hair at the end of the abdomen. According to experts, the females prefer to lay their eggs in moist or watered grass areas. Larvae hatch from the eggs, which eat grass roots and cause damage to meadows and lawns.
The voracious Japanese beetle is now also being combated with nematodes. (Archive image)Photo: Philipp von Ditfurth/dpa
