Abstract
In this study the chemical composition and insecticidal evaluation of the essential oil of Mentha suaveolens L. and Mentha pulegium L. which are growing in Morocco were investigated. The volatile extract was isolated using hydro-distillation technique followed by continuous liquid-liquid fractionation (Water / Ethyl acetate). The essential oil was then analyzed by gas chromatography (GC) and gas chromatography - mass spectroscopy (GC-MS). The major compounds which are characterized in the essential oil of Mentha suaveolens L. were piperitenone (1) (33.03%), pulegone (2) (17.61%), piperitone (3) (9.18%); and of Mentha pulegium L. were pulegone (2) (73.33%), menthone (4) (8.63%). The study of the insecticidal activity of the essential oils on two species of devastating insects of the stored foodstuffs: Sitophilus oryzae and Rizopertha dominica was investigated. The mortality percentage of the species of insects was recorded in the first hours of treatment by the essential oils in the amount of 3, 12 and 50 µL.