Black Currant (Ribes nigrum) as a Living Volatile Organic Compound-Mediated Deterrent against Wild Boar (Sus scrofa): A Novel Hypothesis, Mechanistic Rationale, and Proposed Research Programme

Wild boar cause severe agricultural and ecological damage across Europe and beyond, yet effective non-lethal deterrent strategies remain elusive. Scent-based repellent trials have consistently failed, a result attributed to rapid habituation and chemical degradation of applied preparations—a conclusion valid for extracts but never tested against living aromatic plants. This paper aims to identify a foundational methodological gap in the botanical deterrence literature and advance the first formal hypothesis that a living, constitutively aromatic perennial shrub can function as a self-sustaining olfactory deterrent against Sus scrofa. Through a systematic literature review conducted in May 2026 across Google Scholar, Web of Science, and CAB Abstracts, no published study was identified in which a living, metabolically active plant was used as the experimental deterrent source. All existing trials used processed, extracted, or non-living material. Drawing on published VOC chemistry, field-documented mammalian avoidance data, and recent molecular evidence that plant VOCs activate TRPA1—a conserved mammalian aversion ion channel confirmed in Sus scrofa—a mechanistic rationale and structured five-study experimental programme are presented. This paper represents the first formal scientific proposal that living aromatic plants constitute an untested and potentially highly effective class of mammalian deterrent, and the first hypothesis linking Ribes nigrum specifically to Sus scrofa deterrence via the TRPA1 mechanism.