Distribution and Habitat
P. muscorum is an abundant species in lowland England and Wales, but becomes increasingly sparse in northern England and becomes restricted to coastal sites and low-lying river valleys in Scotland. However, the distribution of this species in Ireland, north Wales, north-west England and especially western Scotland is confused as the many sites shown on the map pre-date the discovery of P. affinis in Britain and Ireland. In western Scotland, at least, it is likely that many records will actually refer to this latter species Gregory (2020).
It has a strong preference for grassy sites of all sorts, and tends to avoid dense woodland (a habitat more suited to the recently discovered P. affinis). Although often numerous within grassland swards, it is most easily found beneath refuge sites, such as dead wood, stones or even dried cowpats.
This summary is based on the detailed account in Gregory (2009).