Here in Europe, we’re seeing an influx of alien species. Species have always moved around, but in these times of international transport and climate change, there’s more of it happening than there used to be.
Newcomers can be exciting. They can enrich people’s lives. It’s hard now to imagine Europe without the potato which came here from the Americas only a few hundred years ago. On the other hand, newcomers can be destructive. They can disrupt ecosystems. The European Environment Agency (EEA) says that ‘biological invasions are one of the main drivers of biodiversity loss.’
Dave Simpson at the Centre for Agricultural Bioscience International (CABI) tells us how this is happening. He tells us about some of the most prominent alien species in Europe now. He says that alien species cost Europe €12bn a year.
[Edit] Here’s an example. The harlequin ladybird or ladybug (Harmonia axyridis) is displacing native ladybirds such as the seven-spot ladybird (Coccinella septempunctata) in Europe. There’s evidence that its success as an invader might be due to its carrying a microsporidian parasite which doesn’t harm it, but kills the native ladybirds.