UC Riverside

The invasive terrestrial gastropod, the slug Lehmannia valentiana, is distributed throughout California. It originates from Europe and is a serious pest of gardens, plant nurseries, and greenhouses. Terrestrial slugs frequently ingest soil and plant bacteria from dead and living plant material while also picking up bacteria on their bodies and in their mucus. These bacteria can then be dispersed as they travel which could possibly cause disturbances to native soil microbial community functioning, as well as cause concern for human health or agricultural crops. Altering soil microbial community composition by slugs, such as interrupting the action of free-living microbes, altering rates of nutrient supply and the portioning of resources may be detrimental to plant communities. Horticulturalists, agronomists, and land managers are recognizing the need to control slug populations in an ecologically sound and effective manner.

Prior to this research, little was known about slug bacterial dispersal. Additionally, information regarding whole slug bacterial microbiomes is limited. This knowledge could provide valuable information for biocontrol studies. Moreover, this research provides evidence for the potential of slugs to disperse bacteria. With the advances of next-generation sequencing, focus on host-microbiome systems have expanded and now include a wider range of plants and animals, notably invertebrates. Bacteria associated with invertebrates may be ecologically significant as these microbes potentially perform many functions, including supporting overall fitness and health. Although invertebrates make excellent study models, minimal work has been conducted on characterizing bacterial associations with terrestrial slugs.

This novel research investigated an invasive California slug, L. valentiana, and documented the ability of this slug to disperse bacteria while providing critical information about its bacterial microbiome and effect on soil bacterial communities. This research may raise awareness to the adverse contributing factors slugs have in environmental and agricultural settings. Additionally, these findings fill a gap in current malacological research, provide material on new methods of slug DNA extraction, and assist in slug bacterial microbiome discovery, which could offer valuable information for future biocontrol studies.