Common name
Common Shiny Woodlouse
Synonyms
Oniscus asellus Linnaeus, 1758
Status:
GB IUCN status: Least Concern
ID Difficulty
Identification
This large familiar grey-brown woodlouse reaches 18 mm in body length. In adults the dorsal surface is smooth and it often has a rather broad, flattened appearance. The continuous body outline, three flagella segments and lack of pleopodal lungs are characteristic of Oniscus asellus. Occasionally pale coloured forms may be encountered.
Small immatures look very different to adults, with the body bearing rough tubercles and marked with a distinctive orange pattern (and are often confused with Porcellio scaber).
In south-west Britain it is partially replaced by a genetically distinct sub-species Oniscus asellus ssp. occidentalis (and intermediate forms of hybrid origin occur sporadically elsewhere).
