295. Leptoiulus belgicus (Latzel, 1884

Iulus belgicus Latzel, 1884.

Julus gracilis Rothenbühler, 1899.

Leptoiulus albolineatus auct.

Distribution

AT, BE, CH, DE, ES-SPA, FR-FRA, GB-CI, GB-GRB, GB-NI, IE, IT-ITA, LU, NL. Extended Atlantic from northern Spain to Germany.

Habitat

Eurytopic but showing a tendency to occur along river courses and in coastal areas, whether in forests, bushy areas, hedges, grasslands, or on sandbanks and dunes. Found in large numbers under stones in the intertidal zone on a sandy beach on the south coast of Wales (Kime 2004). It climbs readily, occurring in vegetation and moss on old roofs in Southwest France. Apparently thermophile, while it shows no clear preference for one type of soil, it favours warm sites in well-drained positions on limestone, light loams or sand. It was found in xeric scrub societies in Saxony-Anhalt, Germany (Voigtländer 2011), and has been regarded as a eurytopic xerobiont woodland species with preference for thermophilous oak woods. Known, too, from a well-drained Fagus silvatica forest with Pinus and Cytisus at an altitude of just below 1000 m in the Haute Loire Department of France, it has been recorded at 1100 m in Spain (Kime 1990) and 1800 m on a south-facing slope in Switzerland (Pedroli-Christen 1993). Sometimes on spoil heaps of old coal mines. L. belgicus is most active in late summer and autumn (Morgan 1989; Pedroli-Christen 1993; Kime 1997).

Remarks

According to the literature it has a highly patchy distribution, more than might be deduced from its supposed preferences. Of the many regions investigated, some have yielded many records and others scarcely any. In Italy, reported only near Aosta (Manfredi 1937) and doubted by Strasser (1978a). It is found nearby in the Upper Rhône Basin.

The white dorsal stripe mentioned in its description is not always present; moreover, marbled specimens possessing absolutely typical gonopods have been found in France. Its regional variability and abundance not only, but particularly in SW France, Benelux and SW England, together with S Wales, suggest that it is a relict species indicative of survival during glacial times.