Chemotactic Responses of Oscheius myriophilus to Mollusk Mucus

Terrestrial slugs and snails can significantly harm agriculture. Due to environmental concerns associated with chemical molluscicides, biological control methods are increasingly being explored. Oscheius myriophilus (Poinar, 1986), a nematode species recently discovered in association with Arion vulgaris Moquin-Tandon, 1855, holds promise as a biocontrol agent for gastropod pests. In this study, we investigated the chemotactic response and motility of O. myriophilus when exposed to the mucus of five mollusk species: Helix pomatia Linnaeus, 1758, Cernuella virgata (Da Costa, 1778), Deroceras reticulatum Müller, 1774, A. vulgaris, and Tandonia budapestensis Hazay, 1880. Our experiments were conducted at two temperatures (20 °C and 25 °C) to assess how environmental conditions influence nematode behavior. The results demonstrated that the chemoattractiveness of mollusk mucus to O. myriophilus was significantly influenced by both the species of mollusk and the temperature. Overall, nematode motility was higher at 20 °C than at 25 °C, indicating that lower temperatures may enhance the activity of O. myriophilus. Among the tested mollusk species, C. virgata mucus consistently attracted the highest number of nematodes, especially at the lower temperature. Our findings indicate that the chemotactic response of O. myriophilus to mollusk mucus may have potential for the targeted biocontrol of pest mollusks. While C. virgata demonstrated strong attractant potential at the tested temperatures, particularly under cooler conditions (20 °C), further research is needed to confirm whether this represents a consistent temperature-related effect. Future studies should aim to identify the specific chemical cues in mollusk mucus that trigger nematode attraction and examine how these signals interact with a broader range of environmental variables, including temperature, to influence nematode behavior.