So I went on this journey of discoveries. Into the unknown. Looking for flatworms…
You might think that in the Netherlands we know all about nature, and have discovered everything there is to be discovered. At least that was my assumption. But a few years ago two scientist went out to look for flatworms. Especially for the New Zealand flatworm (Arthurdendyus triangulatus – Nieuw Zeelandse landplatworm) that was put on the European Union list of invasive alien species in 2019 as it is a predator of earthworms – the worms that we need to create fertile soils. Those of you who read The Hitchhikers’ guide to the Galaxy will recognise it’s scientific name 😊. Anyhow, apparently these creatures are so unattractive, that no one ever bothered to look at them or report any findings. There are bird groups, insect huggers and botanical twitchers, but there is not one single flatworm – society.
Fortunately, they didn´t encounter any New Zealand flatworms. But just few visits to zoos, greenhouses, botanical gardens and city backyards resulted in a handful of new species, never before recorded in the Netherlands. If you want the full background, look here.
Nobody cares for flatworms. And I can’t blame anyone. They look like their relatives, the leeches. And I really, really dislike leeches.

This weekend we did a search party in a butterfly garden. Turning pots and bricks to see what lives beneath. Perfect conditions for flatworms: humid, warm, organic material and lots of tiny creatures crawling in and on the soil. I was very proud to find two individuals of the yellow-striped terrestrial planarian (Caenoplana bicolor or Caenoplana variegata – Grote Australische geelstreep). As the name indicates, it is alien to Europe (look here). Alien, but no threat to biodiversity so not classified as ‘invasive’.
To ease your mind and make you sleep well, I’ll end this story with one of the butterflies of the garden. Sheer beauty.
