Nagurus cristatus (Dollfus, 1889)
GB IUCN status: Not applicable (non-native)
Nagurus cristatus is a medium sized species (to 10 mm body length) with a yellowish and brownish longitudinal pattern on the dorsal surface. It has the general appearance of a slender immature Porcellio scaber, but differs in the shape of the head lobes, notably the medial lobe which bears a characteristic prominent central notch. It also has five pairs of pleopodal lungs. Only females are known (it is believed to be parthenogentic).
A brief description of this species, with figures, is given by Gregory (2014).
There are old records from Northumberland, but the only recent records for Nagurus cristatus are from Eden Project (Rainforest Biome), Cornwall between 2004 and 2010 (Gregory, 2014) and most recently at Birmingham Botanic Gardens in 2017 (Gregory & Lugg, 2020).
It is very widely distributed throughout the tropics and, as an introduction, inside glasshouses elsewhere.
Specimens have been hand sorted or sieved from deep accumulations of leaf litter inside tropical glasshouses.
Gregory, S. (2014) Woodlice (Isopoda: Oniscidea) from Eden Project, Cornwall, with descriptions of species new to Britain, and poorly known British species. Bulletin of the British Myriapod & Isopod Group 27: 3-26.