The phrase "slimy brown flatworm” might not instill fear in the hearts of men, but a recent study published in the journal PeerJ has reported that a predatory, flesh-eating planarian by the same description is currently tearing through gardens in Europe. As globalization has made it easier than ever for all species to globetrot, these Argentinian invaders have squirmed their way across the region at an intimidating rate, munching on local wildlife as they go.
Access to travel is becoming more widely available than ever before, and when humans go abroad, we just love packing some invasive species with us. From the nautical rats who devastated bird populations in South Georgia to the cane toads that, when dumped in non-native Australia in 1935 to control beetles, obliterated quoll and goanna populations, it seems we never learn.
This latest human-facilitated invader is under investigation by an international team led by Jean-Lou Justine of the Muséum National d'Histoire Naturelle, Paris, France. They believe the culprit, Obama nungara, snuck overseas via the international trade of plants, as adult flatworms and their cocoons can easily go unnoticed in potting soil.
While this isn’t the first time a flatworm has invaded France, with previous illegal aliens including the New Guinea flatworm and giant hammerhead flatworm from Asia, it’s the first time an invasion has been so successful, as O. nungara is now found in three-quarters of gardens in Metropolitan France.
Where this becomes a problem is that these predatory, flesh-eating flatworms gorge on earthworms and molluscs, which has the potential to negatively impact soil ecology and threaten the biodiversity of native animals. Its presence has so far been confirmed in Spain, Portugal, Italy, Belgium, and the UK, but researchers have yet to properly evaluate the breadth of spread in these areas.
Study author Professor Jean-Lou Justine wrote that “The wide dispersion of the species and its reported local abundance, combined with the predatory character of the species, make O. nungara a potential threat to the biodiversity and ecology of the native soil fauna in Europe, and probably the most threatening species of all invasive land planarians present in Europe.”
While more research is needed to further assess the impact of these invasive flatworms and confirm the authenticity of citizen science reporting, which, while extremely useful, is vulnerable to bias and misinformation, it seems the outlook for European earthworms could be bleak. In these uncertain times, there may be only one who can save us.