Trichoniscoides albidus (Budde-Lund, 1880)

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 : 30

10. Trichoniscoides albidus (Budde-Lund, 1880)

( Fig. 11 f , Fig. 12 , Map 10 , Table 12)

A small species found in a wide variety of habitats. In the ecological region of the polders Trichoniscoides albidus is almost exclusively found in open landscape, further inland the species is also recorded in forests and anthropogenic habitats ( Map 10 ). T. albidus is an atlantic species in Belgium and very rare in the continental part of the country. In the northern part of the country the species is completely absent in the Campine ecological region, where the soil is mostly sandy and acidic. The species is in forests, compared to open landscape habitat, less bound to water. In forest habitat, 42.4% of the records are close to ditches, stream- and riverbanks and dykes of canals and rivers, while this is 76.5% of the records in open habitat ( Table 12). Since T. albidus has a low desiccation resistance ( DIAS et al., 2013), this can be attributed to the higher and more stable moisture conditions in forests.

In both open landscapes and anthropogenic habitats, T. albidus is more commonly found during winter months ( Fig. 12 ), which can be explained by the dryer conditions in these habitats during warmer months. The corrected number of records in forests is rather constant throughout the year, with the exception of March–April. The reason for the increased number of observations during March–April could be high ground water levels, which peak in this period in Belgium, forcing the species to higher soil layers.

Figures

Map 10. Distribution map for Trichoniscoides albidus.

Fig. 11. a, Ligidium hypnorum; b, Androniscus dentiger; c, Haplophthalmus mengii; d, Hyloniscus riparius; e, Metatrichoniscoides leydigii; f, Trichoniscoides albidus; g, Trichoniscoides helveticus; h, Trichoniscus provisorius.

Fig. 12. Corrected number of observations per two-month period for Trichoniscoides albidus (N = 97).