Habitat and seasonal activity patterns of the terrestrial isopods (Isopoda: Oniscidea) of Belgium Boeraeve, Pepijn Arijs, Gert Segers, Stijn Smedt, Pallieter De Spinicornis Utm, Belgium. Every grid cell of the Belgian Journal of Entomology 1908 116 1 95 4LWK2 (Brandt, 1833) Brandt 1833 [555,1080,202,231] Malacostraca Porcellionidae Porcellionides Animalia Isopoda 79 80 Arthropoda species pruinosus   ( Fig. 20 f, Fig. 38, Map 34, Table 36)  Map 34. Distribution map for  Porcellionides pruinosus.   Porcellionides pruinosusis strongly bound to anthropogenic conditions in Belgium. It can most easily be found in compost heaps in gardens and allotments. The species prefers compost heaps composed of a good mix of kitchen waste (fruits and vegetable waste) and tree leaves, with the largest numbers found on the boundary between dry and wet material. It has also rather commonly been found on farms (often in dung of farm animals), on graveyards (often between waste of potted plants), but also sometimes a few tens of meters away from places with an accumulation of organic material. The locations in forest habitat are from warm forest edges where mown hay or other organic waste was dumped. However, since these forest edges are warmer compared to interior forest the species can probably persist here for several years. In open landscape habitat, the species has only been found next to manmade structures.  P. pruinosusoriginates from the Mediterranean region (  VANDEL, 1962), in Belgiumit can possibly establish populations in (semi-) natural habitat if climate gets warmer. Dispersion via human transportation is presumably the most important way of dispersion for this species. The number of records of  P. pruinosuspeaks during summer months ( Fig. 38) as we can expect for a thermophilic species. However, the vast number of records in May–June is difficult to explain. Probably the species is active year-round in anthropogenic places with rather high temperatures across the year like for instance stables with livestock.