Repellent activity of Origanum vulgare and Artemisia herba-alba essential oils and their major components against the spotted wing Drosophila suzukii

The widespread use of synthetic pesticides in agricultural contexts has caused various environmental and health issues, including contamination of food, soil and water, as well as the development of resistance in target pests. Biopesticides and plant-derived natural compounds are increasingly promoted as sustainable alternatives due to their reduced toxicity, enhanced biodegradability and compatibility with organic farming. Drosophila suzukii is an invasive pest that poses a significant challenge due to its preference for ripe, ready-to-eat fruits, and the limited effectiveness of biological control methods. This study investigates the repellent activity of Origanum vulgare and Artemisia herba-alba essential oils, as well as their key constituents (carvacrol, camphor, and α-thujone), against D. suzukii. The composition of essential oils was determined by GC-MS and their main compounds-α-thujone (9.6%) and camphor (26.02%) in A. herba-alba, and carvacrol (67.05%) in O. vulgare-exhibited a repellent activity against D. suzukii. Repellency index values in the two-choice trap assay were 0.37 ± 0.11 for α-thujone, 0.28 ± 0.07 for camphor, 0.58 ± 0.13 for carvacrol, and -0.57 ± 0.13 for O. vulgare EO. In no-choice oviposition bioassays, carvacrol reduced egg-laying by 51% compared to controls, whereas in paired-choice oviposition assays, O. vulgare EO stimulated egg-laying. Overall, our results contribute to the development of alternative pest management strategies against D. suzukii that align with the principles of integrated pest management and organic farming, thereby reducing dependence on synthetic chemical pesticides.