Fumigation Toxicity of the Essential Oils of Ferula persica against Tribolium castaneum and Ephestia kuehniella

For the first time, the potential fumigation toxicity of the essential oils (EOs) extracted from the flower and root tissues of Ferula persica were evaluated against the adult insects of Tribolium castaneum and the fourth instar larvae of Ephestia kuehniella. The EOs from the flower and root tissues of F. persica were initially prepared using the water distillation method and subsequently utilized for fumigation toxicity assays. To this end, four different series of EO concentrations (each one contained a group of six different concentrations) belonging to both tissues were applied for T. castaneum and E. kuehniella. The experiment was based on a completely randomized design with three replicates, and the mortality rate after 24 hours was employed as a dependent criterion. According to the four individual ANOVA results, in all cases, EO concentration substantially affected the mortality rate of both storage pests of interest. Furthermore, the median lethal concentrations (LC50) of EOs from the flower and root of F. persica against T. castaneum were calculated as 220.832 and 371.475 μL L−1 air, respectively. However, higher LC50 values of 860.041 μL L−1 air and 1268.148 μL L−1 air were respectively detected upon exposure of the fourth instar larvae of E. kuehniella versus EOs from flower and root tissues. Considering LC50 values of the current fumigant assay, it seems that the insecticidal activity of EOs from both flower and root tissues of the plant is less toxic against E. kuehniella rather than T. castaneum. Altogether, the results revealed that these EOs could be possibly nominated as safe botanical pesticides for biocontrol of storage pests, including E. kuehniella and particularly T. castaneum.