The Ability of Terrestrial Mollusks of Moscow Oblast to Feed on Invasive Species of the Genus Solidago (S. canadensis and S. gigantea )

Invasive species have to overcome the biotic resistance of the environment for successful distribution in the secondary range; this resistance can be effectively made by unspecialized phytophages. We carried out a series of laboratory experiments on studying the ability of generalist phytophages, such as terrestrial mollusks, to feed on invasive goldenrod species ( Solidago canadensis L. and S. gigantea Aiton). A significant number of terrestrial mollusks of six species were found on the stems and leaves of goldenrods; however, the results of laboratory experiments have shown that most of them cannot consume this plant as food, and Fruticicola fruticum (O.F. Müller) (Bradybaenidae) and Deroceras sp. (Agriolimacidae) do not choose goldenrod when there are other alternatives, although they can potentially feed on goldenrod. Therefore, snails and slugs in natural populations have a negligible effect on the vital activity of S. canadensis and S. gigantea and cannot suppress the expansion of these species.