New Zealand flatworm

Arthurdendyus triangulatus

Overview

Photo credit: ©The Food and Environment Research Agency (Fera)
Arthurdendyus triangulatus
Habitat:
  • Undisturbed soils near the surface. Under cover such as rocks and stones.

Widely Spread Species:
  • Under Article 19 of Invasive Alien Species Regulation (1143/2014) New Zealand flatworm has been identified as a Widely Spread Species in Northern Ireland and as such, management measures have been put in place to minimise its impacts.

Description:
  • Unlike the well known native earthworm, the invasive New Zealand flatworm does not have the segmented body that is easily recognised.
  • The flatworm does, as the name suggests, have a flattened body that is pointed at both ends and covered in sticky mucus.
  • Colour can vary making it difficult for members of the public to identify but in general specimens are grey, or brown, with a pale yellow margin and underside covered by specks.
  • Download N.I.E.A. ID guide

Origin and Distribution:
  • A. triangulatus originates from New Zealand however other species of predatory flatworms originate from Australia and elsewhere.

Impacts:
  • Earthworms form a pivotal function in terrestrial ecosystems in Ireland. They are responsible for aerating the soil and decomposing plant material while also regulating drainage to some extent by creating burrows.
  • The New Zealand flatworm has been shown to significantly reduce earthworm numbers from both agricultural lands and gardens in Ireland.

How did it get here?
  • It is believed that this species arrived in Ireland by contamination of plant potting soil from New Zealand.

Is it found in Ireland or Northern Ireland?
  • The New Zealand Flatworm was introduced to Northern Ireland in the early 60’s. It is currently known from all 6 counties in Northern Ireland where it is generally concentrated around built up urban areas such as Belfast.
  • The species is present in the Republic of Ireland but may be under recorded.
  • More information can be found at NBDC and NBN Atlas NI.

Static Distribution Map as of December 2019 - Courtesy of CEDaR


Prevent Spread

  • Inspect incoming consignments of plants
  • Maintain good hygiene
  • Inspect your site for flatworms
  • Check plant products for flatworms
  • Report sightings to CEDaR
 
Further guidance and ID downloads;

Current Legislative Position (Listed on 14 August 2019)
  • This species must not intentionally be brought into the Union; kept; bred; transported to, from or within the United Kingdom, unless for the transportation to facilities in the context of eradication; placed on the market; used or exchanged; permitted to reproduce, grown or cultivated; or released into the environment. For further queries, you can contact the Non Native Invasive Species Team in the Northern Ireland Environment Agency on 028 9056 9558.

Species Related Files:

Invasive Species Ireland

Invasive Species Ireland