4-Ethylacetophenone from Potato Plants Repels Phthorimaea operculella and Inhibits Oviposition: A Sustainable Management Strategy

The potato tuber moth ( Phthorimaea operculella ) is a destructive pest that infests potato crops by boring into and eating the tubers. Although chemical pesticides are frequently employed to manage these moths, their efficacy is inconsistent and they can cause environmental damage. In this study, we investigated a natural alternative by examining specific volatiles emitted by potato plants that may repel the moths and inhibit oviposition. We identified five plant-based compounds, one of which, 4-ethylacetophenone, exhibited strong repellent effects against the moths at all tested concentrations and significantly reduced egg-laying behavior. This finding suggests that 4-ethylacetophenone could serve as an eco-friendly way to protect potato crops from P. operculella , providing a safer alternative to conventional pest control strategies. The potato tuber moth, Phthorimaea operculella (Zeller), is an important pest of potato crops capable of boring into and consuming the potato tubers. Although chemical insecticides are employed to control P. operculella populations, their efficacy is frequently limited, raising environmental concerns. Host plant volatiles are important allelochemicals that can be exploited for the management of pests. In our previous studies, we identified five volatile organic compounds (3-ethylacetophenone, 4-ethylacetophenone, geranylacetone, ethylbenzene, and 4-hydroxy-4-methyl-2-pentanone) as allelochemicals potentially influencing the oviposition behavior of P. operculella . Using electroantennography (EAG) and behavioral assays, we found that 4-ethylacetophenone significantly repelled P. operculella at all tested concentrations (1 μg, 10 μg, and 100 μg; p < 0.05), while 3-ethylacetophenone showed no significant effects ( p > 0.05). Finally, the effect of 4-ethylacetophenone on preventing P. operculella from laying eggs was determined by an oviposition selection experiment. Our findings indicate that 4-ethylacetophenone derived from potato plants not only repels P. operculella and prevents egg-laying but also has the potential to reduce the number of eggs, making it a promising green alternative for controlling this pest.