Sensory Quality of Essential Oils and Their Synergistic Effect with Diatomaceous Earth, for the Control of Stored Grain Insects.

Essential oils (EOs) have gained increasing interest as a low-toxic, eco-friendly alternative to synthetic repellents and insecticides against insect pests. However, they have scarce practical application in the protection of stored grain because of their limited efficacy and their interference with the organoleptic properties of the grain. In this study, we evaluated the olfactory profile of the EOs of , , and and their toxicity against the main stored grain pest . Trained assessors identified and , as more suitable than the EO for the wheat treatment. In laboratory tests, the most toxic EO was the (LC = 36.36 μL∙kg) while, the least toxic, was the one (LC = 77.59 μL∙kg). The EOs were also tested combined with diatomaceous earths (DEs) showing synergistic effects (co-toxicity coefficient values ranging from 1.36 to 3.35 for and EOs, respectively). Overall, resulted as the best EO for the wheat treatment, considering its insect toxicity and olfactory profile. In real storage conditions, the wheat co-treated with EO and DEs showed a significantly lower mean infestation (1.5 insect kg) than the non-treated wheat (7.0 insect kg).