Trichoniscoides albidus (Budde-Lund in Meinert, 1880)
Common name
Rough Pygmy Woodlouse
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.
In size, shape and colour this small woodlouse (to 4 mm body length) is similar in appearance to the ubiquitous Trichoniscus pusillus agg. Trichoniscoides albidus differs in having a coarsely tuberculate body surface, eye comprising a single ommatidium and all eye and body pigments are rapidly lost in alcohol (retained in T. pusillus agg.). Thus preserved specimens are difficult to separate from Metatrichoniscoides celticus or M. leydigii.
Video footage of a live specimen of this tiny woodlouse by Duerden Cormack can be viewed here. Note the video begins with a specimens of Trichoniscus pusillus agg. with T.albidus making its appearance after 9 seconds.
Distribution
In southern and eastern England Trichoniscoides albidus widespread, but probably under-recorded. It appears to be rare (and very under-recorded) in Ireland with a handful of widely scattered records.
Habitat
It inhabits damp friable soils in a wide range of habitats, including wet deciduous woodland, alluvial meadows, banks of streams and ditches, seepages on ‘soft’ slumping cliffs, and occasionally churchyards and farmyards.
It is elusive and found with difficulty on the underside of embedded stones and dead wood or amongst damp rubble. It is typically found with Trichoniscus pusillus agg., T. pygmaeus and Haplophthalmus spp.
This summary is based on the detailed account in Gregory (2009).
References
Gregory, S. (2009) Woodlice and Waterlice (Isopoda: Oniscidea & Asellota) in Britain and Ireland. Field Studies Council/Centre for Ecology & Hydrology.
Links
Video footage of a live specimen of this tiny woodlouse by Duerden Cormack can be viewed here. Note the video begins with a specimens of Trichoniscus pusillus agg. with T.albidus making its appearance after 9 seconds.
World List of Marine, Freshwater and Terrestrial Isopod Crustaceans: https://www.marinespecies.org/isopoda/aphia.php?p=taxdetails&id=263616
BRC code
72
idBmigTaxa
Cru_1722