Thirty years of slug control using the parasitic nematode Phasmarhabditis hermaphrodita and beyond

Abstract

Several slug species are highly pestiferous and threaten global sustainable agriculture. Current control methods rely heavily on metaldehyde pellets, which are often ineffective, harm nontarget organisms and have been banned in some countries. A viable alternative is the parasitic nematode Phasmarhabditis hermaphrodita (and recently P. californica), which has been formulated into a biological control agent (Nemaslug®) to control slugs across northern Europe. Nematodes are mixed with water and applied to soil where they seek out slugs, penetrate behind the mantle and kill them in 4–21 days. Phasmarhabditis hermaphrodita has been on the market since 1994 and since then there has been ample research on its use. Here we review the research carried out on P. hermaphrodita over the last 30 years since its development and release as a commercial product. We provide information on life cycle, worldwide distribution, history of commercialisation, gastropod immunity, host range, ecological and environmental factors that affect its success in the field, bacterial relationships, and summarise results of field trials. Finally, we suggest future directions for P. hermaphrodita research (and other Phasmarhabditis species) to enhance its use as a biological control agent to control slugs for the next 30 years. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Immune-Related Gene Profiles and Differential Expression in the Grey Garden Slug Deroceras reticulatum Infected with the Parasitic Nematode Phasmarhabditis hermaphrodita

“…Currently the most common slug control methods rely on chemical pesticides that are primarily mixed into pellet bait-based products [8,9]. For crop protection purposes, the efficacy of these products is highly variable.…”

“…Among these, 47 nematode species from eight families utilize mollusks as definitive hosts [4], some of which are lethal parasites, and thus offer potential as biological control agents due to their natural associations with terrestrial gastropods [26,27]. Notably, only the facultative parasitic nematodes Phasmarhabditis hermaphrodita and Phasmarhabditis californica (Rhabditida: Rhabditidae) have been developed as commercial biological agents of pest slugs and snails in the U.K. and Europe [9]. However, both of these species and other species of Phasmarhabditis have also been found throughout the west coast of the United States [28][29][30][31][32], and P. californica has been found in Alberta, Canada [29].…”