Armadillidium depressum Brandt, 1833


GB IUCN status: Least Concern

ID Difficulty



Armadillidium species and Eluma caelata are readily recognised in the field by their truncated 'square' uropods that end flush with the body and their abilty to roll into a ball.

This large pill-woodlouse (to 20mm) is typically slate grey, sometimes flecked with yellow, and reminiscent of the common A. vulgare.  It differs in the pleon being more curved outwards, giving a 'splayed' or 'flattened' appearence, and often leaves a small gap when enrolled. The male 1st pleopods are diagnostic. 

Warren Maguire
J.P. Richards
J.P. Richards
J.P. Richards
R.E. Jones
Keith Lugg
Nicola Garnham
Nicola Garnham

Distribution and Habitat

It has a distinct south-western bias, but outlying populations, probably a result of recent introduction, occur sporadically. It is heavily synanthropic and typically occurs on dry limestone or loosely mortared walls in towns, villages and farmyards.

It can be found under loose stones, especially capping stones on walls. It may occur in large numbers inside old houses.  It also occurs under rocks and stones in railway cuttings and disused quarries where limestone is exposed.  It can be much easier to find at night (torch-light surveys) when it is active on the surface. It has also been recorded from the trunks of Beech trees (Alexander, 2011). Typically, it is associated with A. vulgare, Porcellio scaber and P. spinicornis.

This summary is based on the detailed account in Gregory (2009).



Gregory, S. (2009) Woodlice and Waterlice (Isopoda: Oniscidea & Asellota) in Britain and Ireland.  Field Studies Council/Centre for Ecology & Hydrology.



BRC Code