Post-harvest losses, dwindling biodiversity, and the extensive use of synthetic pesticides in grain storage systems pose a growing threat to global food security. There is an urgent need for natural solutions that protect terrestrial ecosystems and guarantee safe and efficient food preservation. Bioactive native plants are an underutilized resource, particularly in areas where local species and traditional ecological knowledge have not been thoroughly studied. This study assessed the Mediterranean native plant Inula viscosa's biopesticidal potential for protecting stored grains. Shade-dried leaf powder and essential oil obtained by hydrodistillation using a Clevenger-type apparatus and diluted in 70% ethanol were the two formulations that were tested. Three replicates of each treatment, each containing ten adult insects, were used to apply three dose levels in a hierarchical design. A 70% ethanol solvent control and an untreated control were used to compare the treatments. Repellency was evaluated using two-choice preference tests, and mortality was measured after 24, 84, and 5 days. Within the first 24 hours, the essential oil treatments caused rapid toxicity, which increased by 84 hours and five days. Later on, the powder performed well, achieving extremely high mortality values. These findings align with published research on the insecticidal and repellent properties of essential oils and extracts from Inula viscosa.Overall, Inula viscosa shows great promise as a sustainable botanical agent for lowering post-harvest losses. Its combined effects of repellency and mortality offer an eco-friendly substitute for synthetic pesticides.