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Essential Oils (EOs) from aromatic plants were reported to have an insecticidal activity against several insects and could be an alternative to synthetic insecticides. The aim of this study is to determine the chemical composition of two plants (Schinus molle and Cupressus sempervirens) grown in Algeria and to investigate their insecticidal activity against the sawtoothed grain beetle Oryzaephilus surinamensis, a secondary pest that may alter seriously the proprieties of some food products. EOs were extracted by hydrodistillation using Clevenger apparatus and analyzed by Gas Chromatography/Mass Spectrometry (GC/MS). The analysis determined that the major components of S. molle EO are β-Eudesmol (15.19 %), Elemol (13.97 %), D-Limonene (9.89 %), Spathulenol (9.33 %) and β-Phellandrene (7.72 %) while those of C. sempervirens EO are Cedrol (44.81 %), α-Pinene (15.71 %) and neoiso-Dihydrocarveol acetate (9.7 %). The biological activity of EOs was evaluated by fumigation and repellency at different concentrations and exposure times. Fumigation toxicity bioassays showed maximum efficacy was reached at a concentration of 100 μL/L of air for the two kinds of EOs (90-100 %). Repellency tests revealed that S. molle EO was moderately repellent (55.62 %), while C. sempervirens EO was highly repellent (66.25 %). In fact, the EO of the experimental plants can be incorporated into insecticidal formulations and might be efficient as alternative to synthetic insecticides for O.surinamensis control. However, other tests need to be performed on other life stages of the insect. [ABSTRACT FROM AUTHOR]

This study was conducted to valorise a medicinal plant from the Algerian flora. The main aim is to investigate for the first time the influence of some pedo-climatic parameters on the chemical composition diversity of Cinnamomum camphora L.'s essential oil harvested in two different regions, Algeria. The essential oils were extracted by hydrodistillation method, physicochemical analysis was conducted on the essential oils in order to determine their physicochemical quality, as well as their composition, was analysed by GC-MS. The powder of the leaves and the rhizospheric soil of the two plants was analysed by infrared spectrometry and by X-ray fluorescence spectrometry in order to determine the difference of chemical and mineralogical composition of the powders and the soils from both regions. The GC-MS analysis of the two essentials oils showed a huge difference of their chemical composition and that the essential oil of the plant harvested from Chrea national park (116 compounds are richer than the one harvested in El hamma garden (76 compounds), however, the two essential oils presented some similar chemical compounds mainly: α-Pinene, sabinene, β-Pinene, 1,8- Cineole, camphor, Eugenol and (E)-Nerolidol. The results obtained in this study highlighted the fact that Cinnamomum camphora is a rich source of chemical compounds that can be used in food and pharmaceutical industry however, this chemical diversity is related and influenced by pedoclimatic parameters. [ABSTRACT FROM AUTHOR]