Oniscus asellus Linnaeus, 1758

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 : 46

17. Oniscus asellus Linnaeus, 1758

( Fig. 19 a , Fig. 21 , Map 17 , Table 19)

Oniscus asellus is a eurytopic and very common species across the country ( Map 17 ). The species is very common in every habitat type and in every ecological region in Belgium. Forests are probably its most important natural habitat but the species has adapted to all kinds of anthropogenic conditions ( Table 19). Observed numbers of O. asellus in forest habitat are generally higher compared to other larger very common species like Porcellio scaber and Philoscia muscorum . In forest interiors, O. asellus is probably the most common species of woodlice ( DE SMEDT et al., 2018a). It is one of the few species common in coniferous forest. The species is almost always present in open landscapes when cover of sufficient size is available (like stones, logs etc.), otherwise more rarely detected.

The species is slightly less observed from March until August, with the largest decrease in corrected number of records in May–June ( Fig. 21 ).

Figures

Map 17. Distribution map for Oniscus asellus.

Fig. 19. a, Oniscus asellus; b, Philoscia affinis; c, Philoscia muscorum; d, Platyarthrus hoffmannseggii; e, Armadillidium album; f, Armadillidium nasatum; g, Armadillidium opacum; h, Armadillidium pulchellum.

Fig. 21. Corrected number of observations per two-month period for Oniscus asellus (N = 1221).