Insecticidal properties and chemical composition of essential oils of some aromatic herbs from Morocco

The essential oils (EOs) of Artemisia herba alba, Rutachalepensis and Satureja calaminthaaerial parts were analysed by GC/MS and the EOs were tested for their toxicity against two flour beetles, Tribolium castaneum and Tribolium confusum. EO composition showed that the major compounds were pulegone, menthone and menthol for S. calamintha, camphor and β-thujone for A. herba alba and 2-undecanone for R. chalepensis. Contact bioassay showed that all EOs were toxic to adults of T. castaneum and T. confusum. Higher toxicity was found with the EOs from S. calamintha and R. chalepensis (LD₅₀ of 0.09–0.13 μL/cm² and LD₉₀ of 0.17–0.29 μL/cm²). In fumigant toxicity test, A. herba alba and S. calamintha EOs produced insecticidal activity with S. calamintha EO being more toxic with LD₅₀ and LD₉₀ values of 10.5 and 19.1 μL/L air, respectively, for T. confusum against 7.8 and 17.4 μL/L air, respectively, for T. castaneum.