MolluscIreland - land and freshwater
  • Lehmannia marginata (O. F. Müller 1774) Tree slug
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Lehmannia marginata
© Dr Roy Anderson
Lehmannia marginata
© Dr Roy Anderson
Lehmannia marginata
© Dr Roy Anderson

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Lehmannia marginata
© Dr Roy Anderson

A medium to large grey slug, translucent and very watery in texture. There are two lateral bands behind the mantle and one on the mantle but these are often very diffuse, sometimes missing. Keel short, whitish. Sole greyish-white, mucus colourless and watery. Widespread and common.

Key characteristics

  • A medium to large watery slug
  • Ground colour pale grey to yellowish or brownish with diffuse, broken or missing dark bands across the mantle and back
  • Keel short and near the tail, often marked with a pale line
  • Mucus colourless, watery
  • Mantle with shallow concentric grooves centred on the middle of the back i.e. symmetrical (unlike Deroceras)


70-80 mm.

World Distribution

Found across northern and central Europe to the British Isles. Distribution type: European Boreo-temperate (53).

GBIF distribution map [open in new tab]

Irish Distribution

Ubiquitous in most areas.


  • Widespread and often abundant on trees in woodland and hedgerows as well as on walls and natural rocks
  • It feeds exclusively on corticolous lichens (Cook & Radford, 1988) which means that it is restricted by air pollution and the effect that this has on lichen growth
  • Can be seen crawling high up on the trunks of trees in wet weather and on the walls of houses at night (even in parts of urban Belfast)
  • Common on scree and breccia to the summits of mountrains and on western sea cliffs


There is a small, dark form, regarded by some continental authorities as a separate species, Lehmannia rupicola Lessona & Pollonera. This or a similar form is found widely on upland rocks and coastal cliffs. It is abundant around the basaltic plateau of Antrim and Londonderry and on western cliffs and sea coasts. In other rocky upland or coastal areas the prevalent form is closer to typical woodland marginata. A detailed review of these forms has not been attempted in Ireland.

Red List status

  • Least concern (lc).

Wikipedia link

Wikipedia page for Lehmannia marginata

 Anderson, R., (2016). Lehmannia marginata (O. F. Müller 1774). [In] MolluscIreland. Accessed on 2024-07-13.