Mustapääetana – Krynickillus melanocephalus

The species occurs naturally in the Caucasus region, Crimea, in north-eastern Turkey and north-western Iran. It has been discovered in the 2010s as an invasive species at least in Estonia, Latvia, Germany, Belarus and Russia (Oblasts of Moscow, Novgorod and Tver). In Sweden, the species was first found in 2019. In Finland, the first observations were made in a private garden in Sipoo as early as 2018 but was confirmed only in 2019, in connection with the investigation of the observation in an arboretum in Helsinki.

In its natural range, the Krynickillus slugs live in forests, including the forested areas of the mountains, on rotten stumps and under rocks and fallen trees. It also thrives under leaves and other debris in deciduous forests. The species may also prefer moist locations near water bodies. The Finnish deposits have been found in a park (arboretum) and a garden. It probably overwinters both as an adult and as an egg. The species seems to be very resistant to cold. In Finland, it has been found to be active even after the first frosts.