Common name
Status:
- GB IUCN status: Least Concern
- GB rarity status: Nationally Scarce
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.
Trichoniscoides is a difficult genus and only male specimens of Trichoniscoides helveticus can be distinguished from T. sarsi (or T. saeroeensis). These are small (to 4 mm) creamy-white woodlice flushed with varying amounts of orange with the dorsal surface covered with weak tubercles. In T. helveticus (and T. sarsi) the eye is composed of a single dark red ommatidium (more pinkish orange in T. saeroeensis).
All eye and body pigments are rapidly lost in alcohol, thus making preserved specimens difficult to separate from Metatrichoniscoides celticus or M. leydigii.
Identification is made by microscopic examination of male 2nd endopod, which curves inwards and has a blunt notched tip (like that of an elephant's trunk).
