CRUSTACEA > MALACOSTRACA > ISOPODA > Oniscidea > Crinocheta > Porcellionidae

This is an attractive, medium-sized, up to 9mm long woodlouse with a stepped body outline and two antennal flagella segments. The body colour and general appearance is varied with individuals having shades of yellow, red or brown that intermix to give different mottled effects when mature. Juveniles are equally attractive, but with a more uniform colour. Although brightly coloured, the dorsal surface is rather dull in comparison to some species where the body is noticeably shiny. At first sight, they could be confused with Philoscia muscorum, except that species has three flagella segments.

The narrowing of the body between the pereion and pleon, coupled with two, rather than the more normal three, flagella segments, are combined characters only associated with Porcellionides, of which there are just two British species. Another good identification aid for this particular species are the transverse lines or ridges that run across the rear portion of each segment of the pereion separating a narrow smooth front side from the rough rear side. This feature is particularly useful when looking at juveniles like the one photographed below where the stepped body outline is less obvious than it is in adults.

Porcellionides cingendus is a localised species that has only been recorded from the south and south west of the country, primarily from semi-natural coastal grasslands, but also from scrub and open woodland, where it is typically found beneath deadwood, large stones or mat-forming plants, within tussocks or amongst grass litter. It doesn't have many confirmed sightings, so is either considerably under-recorded or is actually quite scarce. In fact, according to the NBN Atlas at the time of writing, there haven't been any verified sightings in Dorset for over twenty years! I guess that's one of the reasons why it's one of the few woodlice without a common name.

I now need to find some fully mature, properly coloured specimens, as the two individuals featured below are both juveniles.