NEW RECORDS OF EUCOBRESIA DIAPHANA ( DRAPARNAUD , 1805 ) IN WESTERN POLAND

Eucobresia diaphana (Draparnaud) is a European land snail which is distributed from France in the west to Bulgaria in the south-east. It is listed in the Red List of Threatened Species in Poland where it occurs in the Sudetes; its range is mainly limited to Lower Silesia. We found five localities of E. diaphana in the Lubuskie province (W. Poland), beyond the known range of this species.

Eucobresia diaphana (Draparnaud, 1805) is a Eu ropean terrestrial semi-slug of the family Vitrinidae.Its distribution range extends from France in the west to Bulgaria in the south-east (Kerney et al. 1983, iriKov & eröss 2008, HorsáK et al. 2013).The species is listed in the Red List of Threatened Species in Poland (wiKtor & riedel 2002).E. diaphana is frequent in the Sudetes in the southwestern part of the country (umińsKi 1980); its occurrence was thought to be limited mainly to Lower Silesia (red-colored, hatched area in Fig. 1; wiKtor 2004).Typical Polish habitats were described as moist places near creeks and covered with tall herbs, or on moist rocks (wiKtor 2004).
Besides the above mentioned mountain localities, urBańsKi (1958) reported that he found an empty shell of E. diaphana in the western, lowland part of Poland -near Łagów, Lubuskie province (square WT29 in Fig. 1).Based on this record, umińsKi (1980) suspected that E. diaphana was probably more widespread in the Lubuskie province, but this part of Poland had hardly been explored by malacologists in those days.
Our research was conducted in western Poland in 2011 and included 49 moist habitats such as sedge meadows, tall herbs near rivers or lakes, as well as grasslands.Each chosen site was searched for mol-luscs by the two authors for 30 minutes (total: 60 minutes).We found the following five new localities of E. diaphana in the Lubuskie province (Fig. 1 1. We did not find the species in other localities sampled on the same occasion, despite the presence of habitats described as adequate for the species by wiKtor (2004), such as moist, tall herbs near rivers.Thus, E. diaphana in the Polish lowlands most probably occurs under somewhat different ecological conditions than in the Sudetes.
Our studies indicate that E. diaphana is more common in western Poland than it was previously thought (cf.Kerney et al. 1983, wiKtor 2004).It is noteworthy that the species was not recorded in similar localities in the Wielkopolska province, ca.100-200 km to the east (KsiążKiewicZ et al. 2015).Considering the range of E. diaphana according to welter-scHultes (2012), it can be suspected that the species' distribution range covers the areas of western Poland, since it commonly occurs across Germany.However, the distributional data of Kerney et al. (1983) andZettler et al. (2006) indicate that the Polish localities of E. diaphana in the Lubuskie province are isolated, since the species was not recorded along the German-Polish border.Nonetheless, E. diaphana should be regarded as rare in Poland and, since its habitats are vulnerable and prone to the degradation, it should still be considered a threatened species in the country.

Fig. 1 .
Fig. 1.Distribution of E. diaphana: black squares -records presented by umińsKi (1980); red squares -new records where square VT83 contains 3 records of the species; area hatched in red -range of E. diaphana according to wiKtor (2004)