Androniscus dentiger Verhoeff, 1908

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 : 16

3. Androniscus dentiger Verhoeff, 1908

( Fig. 5 , Fig. 11 b , Map 4 , Table 6)

A species commonly found in anthropogenic habitats but there are also a number of records from forests and open landscapes ( Table 6). In the northern part of the country Androniscus dentiger is mostly found in anthropogenic habitats in urban areas, with other records situated in habitats with at least some degree of human influence, like gardens, river dykes and near buildings in open landscape. In southern Belgium the species also occurs in forests, with some locations having a clear human influence (roads or buildings) but others not. In the last case, it concerns observations of the species at stream- or riverbanks and mostly in areas with calcareous soil. Based on the numerous records in habitats with human influence, e.g. graveyards, gardens, parks and old quarries, it can be presumed that dispersion by human activity is an important vector for its dispersion. A. dentiger is known to be troglophile ( VANDEL, 1960; GREGORY, 2009) but no caves were searched for isopods during the 2014– 2020 field surveys. The species has been found in caves in Belgium in the 1930’s and 1980’s, see DE SMEDT et al. (2018b) for all literature references.

Androniscus dentiger seems to be more active in open landscape during winter months ( Fig. 5 ), possibly because these habitats are too dry in summer months. In anthropogenic habitats the lowest corrected number of records is in January–February, followed by the highest number in March–April. From May until August A. dentiger appears to be slightly less active than in the months September until December. Since this species has a Mediterranean origin ( VANDEL, 1960) and seems to prefer wet microhabitats, the pattern in phenology might be explained by a combination of low temperatures in January-February and dryer conditions in the summer months.

Figures

Map 4. Distribution map for Androniscus dentiger.

Fig. 5. Corrected number of observations per two-month period for Androniscus dentiger (N = 141).

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.