Gulella io Verdcourt, 1974 and Oxychilus alliarius (Miller, 1822): first reports of two greenhouse snails in Italy (Gastropoda: Streptaxidae, Oxychilidae)

Several species new for Italy, including Gulella io and Oxychilus alliarius, were found during surveys on alien slugs and snails in greenhouses of Italian botanical gardens and scientific museums. Gulella io is native to tropical Africa but has been described from specimens collected in European greenhouses since the 1930s. Two shells and living juvenile specimen of this species were collected in 2019 in the Botanical Garden of Padua. Oxychilus alliarius has a wide range in Europe but is absent from Italy: previous records have generally proved to be based on misidentification of other Oxychilus species. Several shells and living specimens were found in 2024 in the Aquarium of Genoa; a bleached shell probably belonging to O. alliarius had previously been found in the Citta Studi Botanical Garden, Milan. Easily transported with plants, this predatory snail has been unwittingly introduced to almost all countries of the world and in some areas is threatening the native fauna. Unlike tropical species, it may escape from greenhouses and acclimatize in Italy, but its impact is likely to be negligible since many members of this genus with a similar ecology are already present and widespread in the country.