Switzerland is increasingly affected by invasive plant and animal species that are not officially authorized in the country but arrive there from surrounding EU countries. For example, the Japanese beetle now poses a threat to agriculture in the non-EU country of Switzerland.
Of the invasive exotic species, 41 percent originate from Asia and 30 percent from North America. The introduction of these foreign species occurs in various ways: 40 percent were intentionally introduced and subsequently accidentally released into the environment. A further 32 percent were inadvertently transported to new areas with traded goods. For 18 percent of the exotic species, the method of introduction is unknown.
The Japanese beetle first appeared in Europe on the Spanish Azores islands off the coast of West Africa in the 1970s. It was then discovered in northern Italy in 2014 and in 2017 the beetle was found for the first time in southern Switzerland.
Isolated sightings of the Japanese beetle have since been made north of the Alps: in 2021, the city nursery in Basel recorded its first discovery. The Japanese beetle is voracious and feeds on more than 300 different types of plants; it causes extensive damage both as a larva in the soil and as a beetle on many cultivated plants, damaging fruit harvests ahead of time.
Switzerland now has 1,305 such exotic species. “Only” 15% of these are invasive and pose a major problem for agriculture. Among these are 430 animals, 730 plants, and 145 fungi. Of these, 197 species have been classified as invasive, meaning they pose a risk to humans and the environment, degrade biodiversity, or disrupt ecosystem services and their sustainable use.
In the EU, the Asian ladybird was deliberately introduced in the 1980s for the biological control of aphids and is mostly released in greenhouses. The insect was never approved for use in organic crop protection in Switzerland but was still first discovered there in 2004. Since then, it has multiplied and spread extensively.