Chemical Composition and Efficacy of leaf and Stem Essential Oils and Their Fractions from Ferula Tunetana Pomel ex Batt. as Promising Botanical Insecticides Against Tribolium castaneum (Herbst)

As synthetic insecticides cause many adverse effects, plant-based materials, mainly essential oils, are becoming popular as safer alternatives. It is in this context that the current study was included to show for the first time the chemical profiles and the insecticidal efficacy of Ferula tunetana (F. tunetana) leaf (LEO) and stem (SEO) essential oils and their fractions resulting from chromatographic separation against Tribolium castaneum adults. Fifty-three constituents were detected in LEO, with (Z, E)-farnesol (17.5%), bulnesol (13.9%), alpha-cadinol (11.0%) and guaiol (10.2%) as dominant compounds. The SEO was rich in alpha-cadinol (19.9%) and oplopanone (19.9%), as well as forty-seven other compounds. The chromatographic simplification of both EOs led to the identification of additional constituents. At a concentration of 0.12 mu L/cm(2), the LEO, SEO and the most of their fractions showed excellent repellent effects with percentages ranging from 63 to 97%. The fumigation bioassay proved that crude LEO was more potent than SEO and the most interesting insect mortality rates were found for the L-4, L-5 and S-5 fractions with median lethal doses of 199.87 mu L/L, 162 mu L/L and 187 mu L/L, respectively. The S-3 fraction showed the most interesting topical toxicity at a concentration of 10% with LD50 = 8.2%. A molecular docking study of the main phytoconstituents of LEO and SEO revealed the two studied EOs as efficient botanical insecticides even on larval stages. This work highlighted the considerable potential of F. tunetana in pest control during storage.