Flatworms - our unwanted aliens

New Zealand flatworm is a predator of the earthworms which keep our soils in good condition and are a source of food for lots of animals and birds. The flatworm has been known to reduce earthworms to below detectable levels.

Surveys carried out for the Scottish Office Agriculture and Fisheries Department and Tomorrows World, showed that it initially spread only slowly and was mainly found in botanic gardens, nurseries and garden centres. However, by 1994 it was usually found in domestic gardens and is now recorded from most of Scotland including the islands of Skye, Coll, Islay, Orkney, Shetland and Lewis.

Since then the percentage of garden centres infested has decreased and now the New Zealand flatworm is probably mainly spread by the exchange of containerised plants between neighbours, relatives and friends.

Spread of New Zealand Flatworm in Scotland

The New Zealand flatworm likes cool damp conditions and can become established in agricultural land in Northern Ireland, the west of Scotland and the Faroe Islands. It has not yet been found in Continental Europe.
It reproduces by laying an egg capsule which usually has inside it 6-7 creamy coloured 'hatchings'. It probably feeds at night on the soil surface where it catches earthworms and digests them externally and then sucks up the resulting 'soup'.
During the day the New Zealand flatworm hides under polythene bags, bits of wood or stones and that is where to look for them.

Have you seen any of these?
In the last 5 years 3 more species of flatworm have been found in Scotland so we now have the following 4 species:

Please help the research into these aliens by reporting any sightings to:
Brian Boag,
Scottish Crop Research Institute, Invergowrie, Dundee. Scotland DD2 5DA.
Telephone: 01382 562731 Fax: 01382 562426
Email: bboag@scri.sari.ac.uk