Pill millipede  (Glomeris marginata)

The pill millipede is often confused with the pill woodlouse (Armadillium vulgare), but can be distinguished by its shiny cuticle, the presence of a large 'shield-like' plate behind the head, and the fact that it has more legs than the woodlouse (2). When threatened, this species rolls into a tight ball, hence the common name (3). Most pill millipedes are shiny and black in colour, although red, yellow and brown individuals occur (2).

Although widespread and common in Britain, this millipede has not been recorded further north than Edinburgh (1).

Seems to prefer calcareous soils, and can be found amongst leaf litter in woodlands (4), fields and hedgerows (2).

This species feeds on dead organic matter (1); it tends to be active mainly at night, and shows a preference for humid areas, such as below logs and stones, to avoid desiccation. However, thanks to its ability to roll into a ball, it is much more tolerant of dry conditions than many other species of millipede (4).

Males transfer sperm to females by means of heavily built, modified rear legs known as gonopods (3). Eggs are laid singly, and are coated in a protective layer of digested earth, secreted from the anus. It takes around 3 years for juveniles to reach maturity, during this time they progress through nine moults, and the adults then continue to moult periodically (4). British pill millipedes are known to have lived for as long as 11 years (3).

Not threatened at present.

Conservation action has not been targeted at this common species.

For more on invertebrates and their conservation see Buglife, the Invertebrate Conservation Trust at:
http://www.buglife.org.uk/

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk