A flatworm is spreading through plant trade and threatening soil fertility. Sweden has already taken emergency measures on imports.
The flatworm concerns Obama nungara, the large spotted land flatworm native to Brazil and Argentina. Through plant trade, this flatworm is spreading around the world. In 2008, Obama nungara was first found on the British island of Guernsey. The flatworm has since been found elsewhere in the UK, in Spain, France, Portugal, Italy, Switzerland and Belgium.
Eats benthic animals, including earthworms
The NVWA assessed the risk to the Netherlands in 2020. In 2023, Minyoo Advies, commissioned by the NVWA, conducted an additional survey on Obama nungara and other alien land flatworms. An inventory at 25 greenhouses at nurseries, hortuses and zoos revealed 125 land flatworms in 16 greenhouses. Of these, 101 were non-native and 29 specimens of Obama nungara in 3 greenhouses.
Among other things, Obama nungara eats earthworms, therefore posing a potential indirect risk to land fertility. From Brazil and Argentina, the flatworms are known to eat many (other) soil animals, so there is a potentially high impact on ecosystems.
The flatworm is not yet EU-regulated, but Obama nungara is now included in the EU consultation on expanding the EU list of invasive exotic species. Read the EU risk assessment here. Sweden has already taken emergency measures to prevent the introduction and spread of the flatworm. The Swedish government has shared this information with Swedish buyers/buyers.
Trade with Sweden? Follow these 10 steps
Sweden now considers all plant material from Europe to be at risk, as the flatworm has already been found on several plants from various companies. For now, Sweden assumes that all imports could be infected. You should do this before sending plants to Sweden:
- Wear gloves, as slime from the flatworm can irritate your skin;
- When checking, also use a torch during the day, as flatworms often light up then. They are especially active after screening, though;
- Check (potting) soil for flatworm by loosening pot, container or tray;
- Also look under the pot, container or tray;
- Also look for possible eggs (0.5 cm; dark red/dark brown);
- Collect all flatworms and/or eggs found;
- Pour boiling water over them or put them in the freezer for a day; they will die.
- Do not cut flatworm into parts; this is not sufficient to kill it.
- Temporarily isolate the plants in which the flatworm was found, and check them again the next day.
- In case of multiple finds, continue the above steps. Nothing more found for two days? Then the risk of spreading has been minimized and the plants may enter Sweden.
Source: LTO