Porcellio scaber Latreille, 1804

Boeraeve, Pepijn, Arijs, Gert, Segers, Stijn, Smedt, Pallieter De, Spinicornis & Utm, Belgium. Every grid cell of the, 1908, Habitat and seasonal activity patterns of the terrestrial isopods (Isopoda: Oniscidea) of Belgium, Belgian Journal of Entomology 116, pp. 1-95 : 76

32. Porcellio scaber Latreille, 1804

( Fig. 20 d , Fig. 36 , Map 32 , Table 34)

Porcellio scaber is probably the most abundant, widespread and most eurytopic species in Belgium. It can be found in a wide array of habitats across the whole country ( Map 32 ). However, compared to other eurytopic species like Oniscus asellus and Philoscia muscorum it occurs less in forests and more in anthropogenic habitats. In forest habitat, the species can reach very high numbers in forest edges, but numbers are generally lower in closed interior forest habitat ( DE SMEDT et al., 2016b, 2018d). It is one of the few species that can also be abundant in coniferous forest in the Campine ecoregion. Due to its high drought resistance ( DIAS et al., 2013) it can also be found higher up in the vegetation or on the bark of living trees. In open landscapes, the species occurs in similar numbers as other eurytopic species. Together with P. spinicornis , P. scaber is one of the few species that is also regularly found inside buildings and houses.

The corrected number of records for P. scaber throughout the year is rather constant ( Fig. 36 ). A slight drop appears in March–April in anthropogenic habitats and in September–October in forests. Generally speaking, P. scaber is observed at constant levels throughout the year whereas Armadillidium vulgare is found more during summer months and O. asellus less. This corresponds with the drought resistance for P. scaber lying in between the values for A. vulgare and O. asellus ( DIAS et al., 2013) . DE SMEDT et al. (2021) however, found a peak during the summer months in different habitat types, but this peak was less pronounced compared to the more drought resistant A. vulgare .

Figures

Map 32. Distribution map for Porcellio scaber.

Fig. 20. a, Eluma caelata; b, Cylisticus convexus; c, Porcellio monticola; d, Porcellio scaber; e, Porcellio spinicornis; f, Porcellionides pruinosus; g, Porcellium conspersum; h, Trachelipus rathkii.

Fig. 36. Corrected number of observations per two-month period for Porcellio scaber (N = 1373).