You probably don’t know all of these invasive species

The world has become smaller. Crowds of tourists fly all over the world, huge amounts of trade goods are shipped to distant areas. Live animals, plants, fungi and micro-organisms also travel with people and goods – intentionally or unintentionally – to areas that they would never have reached without human transport infrastructure.

Others are encroaching on new territories on their own, in part because global warming allows them to survive in previously unsuitable habitats. These creatures, migrating from their natural range to new regions, are called extraterrestrial there.

Most non-native species that come to us integrate unobtrusively into our ecosystems – an example of this is the horse chestnut. But that does not apply to all species: some can cause problems, for example because they put pressure on or even displace native species and thus threaten our biological diversity, biodiversity.

They can also damage crops, damage infrastructure or otherwise cause economic damage. And some of them also endanger human health. Such species are considered invasive alien species.

The technical term for alien species is neobiota (from Ancient Greek νέος = «new» and βίος = «life»). They are divided into neophytes (plants), neozoa (animals) and neomycetes (fungi). As early as the Neolithic, with the onset of agriculture, new species came to our region and settled in the wild; however, they are not considered neobiota.

The demarcation of the native species (archaeobiota) dates back to the year 1492, when the Old and New Worlds became one with the discovery of the Americas and the transcontinental trade that began with it.

The Federal Environment Agency (FOEN) lists more than 1300 established alien species (430 animals, 730 plants, 145 fungi) in the report “Alien species in Switzerland”. 197 of those, about 15 percent, are considered invasive: 85 animals, 89 plants, and 23 fungi. The number of non-native species in Switzerland has grown rapidly over the past two hundred years. The share of invasive species among them has also steadily increased:

We limit ourselves here to the animal species; Plants, fungi and micro-organisms are not taken into account. For example, the Japanese beetle, about which the Federal Bureau of Agriculture recently warned, is one of the invasive neozoa.

A well-known example of invasive animal species are American crab species. Three of them were left behind in Europe. The problem here: the neozoa from America brought the crayfish plague. Because they themselves are largely immune to this fungus while the native crabs die from it, they can reproduce heavily at their expense.

The American crabs threaten local biodiversity, but do not endanger human health. The situation is different with the Asian tiger mosquito. This blood-sucking insect, originally from Southeast Asia, probably came to Europe in the form of eggs and larvae in old tires filled with rainwater.

The Asian tiger mosquito has been shown to transmit numerous tropical infectious diseases, including chikungunya and dengue and Zika virus diseases. However, so far no such transmission has been registered in Switzerland.

Here are the 55 invasive neozoa from the FOEN species list that have been proven to cause environmental damage: