|Black ants busy around a hole in a gatepost.|
|Note on the left - one ant placing building material|
|Hind tibia with standing hairs|
|Head, including antennal scape with standing hairs (see below the eye)|
|L. flavus and P. hoffmannseggi - both around 3-4mm long|
|P. hoffmannseggi - the yellow colour is just due to lighting/image processing...|
P. hoffmannseggi is an interesting beast - it is white (in the top photo you can just see dark gut contents through its dorsal surface), blind and lives closely associated with ants of almost any species (Hopkin 1991), often found in their nests where it may feed on pellets regurgitated by the hosts (Williams & Franks 1988) and/or may be a more general scavenger in the 'rubbish-dump' parts of nests (Pontin 2005). It has also been noted as following lines of ants when nests have moved (Donisthorpe 1927). This is unusual behaviour for a woodlouse (it is the only myrmecophilous - 'ant-associated' - woodlouse in Britain), but not unique - in Malaysia there is a species of Exalloniscus which 'hitchhikes' (maybe 'stows away' is more accurate) on the pupae of ponerine army ants. Although not often seen without digging, it is fairly common in southern England and Wales, becoming scarcer northwards (will climate change extend its range, and if so, how does it disperse?). Beyond this, little is known about P. hoffmannseggi - an area for a keen researcher to work in maybe?
Donisthorpe, H. St. J. K. (1927). The Guests of British Ants.Routledge, London. [interesting if you can find it, but can be expensive]
Hopkin, S. (1991). A key to the woodlice of Britain and Ireland. Field Studies 7(4): 599-650. [this has also be published in separate reprint form]
Pontin, J. (2005). Ants of Surrey. Surrey Wildlife Trust, Woking. [another volume in the excellent series of Surrey atlases]
Skinner, G. J. & Allen, G. W. (1996). Ants. Richmond, Slough. [excellent keys to British species]
Williams, T. & Franks, N. R. (1988). Population size and growth rate, sex ratio and behaviour in the ant isopod Platyarthrus hoffmannseggi. Journal of Zoology 215: 703-717.