Armadillidium opacum (C. Koch, 1841)

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 : 58

23. Armadillidium opacum (C. Koch, 1841)

( Fig. 19 g , Fig. 27 , Map 23 , Table 25)

The vast number of records of Armadillidium opacum is situated in forest habitat (83.1% of the records, see table 25). Across the country it is characterised as a species with a strong forest affinity ( DE SMEDT et al., 2020b) and in the north it is a characteristic species from ancient woodland and closed forest habitat ( DE SMEDT & VANDEKERKHOVE, 2020). In the south and east of the country, the species is more common and more frequently found in other habitat types. Especially in the east of the country, the species can be found outside forest where it replaces A. vulgare as most common Armadillidium- species in (semi-)natural habitat. The species has been found in grasslands but always in close vicinity to ancient woodland. The correct number of records strongly peaks in May–June ( Fig. 27 ), coinciding with the species breeding period ( DEVAERE, 1999).

Figures

Map 23. Distribution map for Armadillidium opacum.

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. 27. Corrected number of observations per two-month period for Armadillidium opacum (N = 89).