<i>Pellioditis ciscaucasica</i> n. sp. from Caucasian gastropods and a role of the invasive slug <i>Krynickillus melanocephalus</i> in dissemination of malacopathogenic nematodes

Invasive agriolimacid slug <i>Krynickillus melanocephalus</i> was found infected by several species of malacopathogenic nematodes of the genus <i>Pellioditis.</i> Now, this Caucasian slug is actively spreading across Europe. <i>Pellioditis</i> is a genus of nematodes capable of killing molluscs, and its two species have been developed into widely used biological control agents. As malacopathogenic nematodes can pose a threat to survival of native, susceptible gastropod species, the distribution of <i>K. melanocephalus</i> and examination of associated parasites are needed. All <i>Pellioditis</i> species found in association with <i>K. melanocephalus</i> were of Caucasian origin. The new <i>Pellioditis</i> species was found to belong to a different clade within the genus than the other five Caucasian species and is the first representative of the clade <i>Papillosa</i> in the Caucasus.