Armadillidium nasatum Budde-Lund, 1885
GB IUCN status: Least Concern
Our seven Armadillidium species and Eluma caelata (Family Armadillidiidae) are readily recognised in the field by their truncated 'square' uropods that end flush with the body and their ability to roll into a protective sphere (similar truncated uropods are also seen in the non-native Armadillidae species).
Armadillidium nasatum is a large pill-woodlouse (to 12mm body length) is reminiscent of the common A. vulgare. However the narrow protruding scutellum (snout), reminiscent of the peak of a base-ball cap, is diagnostic. It usually has a dark grey body marked with pale longitudinal stripes that give a semi-translucent appearance, but dark and coloured forms may also be encountered. When disturbed it forms an imperfect ball, with its antennae protruding.
Armadillidium nasatum occurs patchily across southern England and south Wales, with outlying populations in Scotland and Ireland.
It is characteristic of dry, sparsely vegetated habitats, both semi-natural and synanthropic, that are subject to high levels of insolation. In more southern areas this includes coastal grassland, limestone screes, disused limestone quarries, railway lines, industrial waste ground and garden centres. Further north it becomes increasingly restricted to garden centres and inside greenhouses.
It is typically found under rocks, stones, pieces of wood, potted plants and other debris or amongst rubble, often with A. vulgare.
This summary is based on the detailed account in Gregory (2009).