Becoming more attractive: Optimizing dead-end plant performance against spotted wing drosophila (Drosophila suzukii)

The invasive spotted-wing drosophila Drosophila suzukii has led to intensified insecticide use in soft-skinned fruit production, highlighting the need for alternative management strategies. Plant-based approaches, including trap cropping, have already been explored. However, field evidence for effective “dead-end” plants (species that elicit oviposition without successful offspring development) remains limited. In this study, we evaluated candidate ornamental species for their potential to function as demographic sinks under realistic conditions. We quantified both oviposition intensity and subsequent adult emergence to identify plant species where high oviposition intensity coincided with limited adult emergence. Field data revealed substantial variation in fruit acceptance and oviposition intensity among species. Several candidates, including Phytolacca acinosa and Prunus lusitanica received substantial oviposition but showed no successful adult emergence, indicating strong developmental constraints. However, overall oviposition levels on the selected species were low, limiting their effectiveness as sinks under field conditions. To enhance sink strength, we experimentally increased fruit attractiveness by application of a fermentation-based attractant solution (apple cider vinegar, red wine and sugar). In laboratory two-choice assays, this treatment significantly increased oviposition across most plant species while developmental success remained low. This effect was particularly pronounced for Pyracantha coccinea and Sorbus aucuparia . Our results suggest that combining behavioral manipulation with developmentally unsuitable host plants may enhance ecological trap function. Exploiting maladaptive host choice in polyphagous pests using attractant-enhanced dead-end plants may thus offer a novel pathway toward reducing dependence on insecticides in berry production systems.