Common name
Status:
GB IUCN status: Least Concern
ID Difficulty
Identification
The pygmy woodlice of family Trichoniscidae (and Styloniscidae) are readily distinguished from other woodlice by the shape of the antennal fagellum which comprises a tapered cone (of indistinct segments) bearing a terminal bristle.
Trichoniscus species are characterised by having the eyes composed of three ommatidia and a smooth body surface. Body and eye pigments are retained in alcohol.
Trichoniscus pygmaeus is one of our smallest woodlice, reaching 2.5 mm in length, and often confused with juveniles of other species. T. pygmaeus is usually pale pinkish-yellowish in colour, but characteristically the head appears noticeably pale relative to any body pigmentation.
Of potential confusion species; immature T. pusillus agg. has the head is speckled with pigment to match the body colour while both Trichoniscoides spp. and immature Androniscus dentiger have the body covered in tubercles and eyes comprising a single ommatidium.
