Common Pygmy Woodlouse Trichoniscus pusillus agg.


Common Pygmy Woodlouse Trichoniscus pusillus agg
Common Pygmy Woodlouse Trichoniscus pusillus agg

Class Malacostraca (Malacostracans)
Order Isopoda (Woodlice)
Family Trichoniscidae
Species Trichoniscus pusillus agg. Brandt,1833

Length up to 5 mm.

This small woodlouse is coloured with reddish or purplish-brown pigments. One of the ‘famous 5’ very common British species most likely to be seen. Recent studies have shown that there are in fact two very closely related species, the other being Trichoniscus provisorius Racovitza, 1908, which can only be separated by looking at differences in male genitalia with a microscope, hence the term ‘agg.’ to describe the species pair. The females are visually indistinguishable.

Feeds on dead plant matter, like leaf litter and rotting wood. Seen all year round in gardens under stones and logs, or in damp soil and leaf litter in woodland. Common and widespread thoughout Britain, and probably the most abundant woodouse to be found in woodland. Native to Britain.

Discovered in back garden, South Staffordshire. © Peter Hillman.

Species recorded and verified via iRecord.