Although superficially similar to the ubquitous P. muscorum in general appearence, the pigmentation of the head and body is a good guide to identification, but reliable identification requires microscopic examination of 7th pereiopod of a male specimen.
A description, with figures, is given by Segers, Boeraeve & De Smedt (2018).
Distribution and Habitat
The presence of this species in the UK was first confirmed in south-east England in summer 2017 (Segers, Boeraeve & De Smedt, 2018).
Subsequently, specimens collected in 2007 from Oban, western Scotland (but, mis-identified as P. muscorum) have been recognised and several additional sites have been discovered, mainly in western Britain, such as north Wales (Hughes, 2019), and in Northern Ireland (Anderson, 2019). This species has clearly been over-looked in Britain and Ireland and could prove to be widespread if searched for.
This species has a preference for woodland sites, and seems to favour western areas (Gregory, in prep.), whereas P. muscorum favours grassland sites.