Obama nungara, the leaf flatworm, can grow up to 8cms long.
In November 2024, a brown, slug-like creature is discovered in Skåne. It is identified as the South American flatworm Obama nungara – the first confirmed sighting in Sweden.
The flatworm grows to 5–8 centimetres long and has a slimy, brown body that shifts in colour. It is about a centimetre wide and covered in mucus or slime. This small creature could have devastating consequences for Sweden’s ecosystem.
– The species is highly invasive and is related to the New Zealand flatworm that has spread to the UK, Ireland and the Faroe Islands. It is estimated to be capable of reducing agricultural output by 20 percent, which we fear could happen in Sweden, says Lena Bondestad, a biologist and conservation officer at Länsstyrelsen Norrbotten.
The eggs of the leaf flatworm are white at first but gradually turn red and eventually black, and are difficult to spot.
If the flatworm were to spread into the wild – of which there is currently no evidence in Sweden – it could disrupt the ecosystem, as its preferred food is earthworms, which play a vital role in soil health. So far, the worm has only been found in imported potted plants.
– Since the species is new to us, we don’t know how it reacts to the weather and environment. It has been observed surviving the winter in one location in Skåne, but it's much colder here, up north. At the same time, people once said Spanish slugs wouldn’t be a problem in the north for the same reason – but that turned out to be completely wrong.
Spanish slugs have become more common in the north over the past year, though only a few have been found in Norrbotten.
– The flatworm is invasive for a reason – it’s very good at surviving. If it escapes and manages to find a spot where there’s no frost, like beneath a building foundation, it could burrow down and survive there.
Obama nungara, the leaf flatworm, is brown and slimy.
So far, no cases have been reported in Norrbotten, but Lena Bondemark believes it's too early to feel safe.
– We believe we’re going to get it. It just feels like a matter of time since it’s been spreading county by county since it was first discovered.
At Nolia Garden in Umeå, concerning news emerged over the weekend.
– A woman came up to us and said they had found something in a potted plant that unfortunately looked very much like the flatworm. We’re afraid we might have the first sighting in Umeå.
Lena is encouraged by how many people have received the information about the flatworm.
– It’s incredible how quickly the information has spread and how seriously people are taking the risk. Some are even hesitant to buy plants anymore. But as long as people inspect their plants carefully, we can reduce the spread, because if it gets out into nature, it’s basically game over. There’s no chance of finding it across such large areas.