Chemical composition and insecticidal activity of five essential oils: Cedrus atlantica, Citrus limonum, Rosmarinus officinalis, Syzygium aromaticum and Eucalyptus globules

The use of essential oils as bio-insecticides presents many previous world works particularly in Morocco. In addition, the present work is concerned with the measurement of the insecticidal activity of five essential oils: Cedrus atlantica, Citrus limonum, Rosmarinus officinalis, Syzygium aromaticum and Eucalyptus globulus, against insect pests of the flour (Tribolium confusum). After extraction by a Clevenger distiller of the five species, the chemical composition of the extracted essential oil was studied by gas chromatography coupled with mass spectrometry (GC-MS). The majority of the identified compounds of Cedrus atlantica are: alpha-himachalene 15.63%, beta-himachalene 31.24% and gamma-himachalene 14.46%. The major components of Citrus limonum are: Neral 13.60%,Neryl acetate 10.77% and alpha-Pinene 9.46 %. The majority compounds of Rosmarinus officinalis are: (-)-camphor31.16%, beta-Caryophyllene 18.55% and 2,4-hexadiene, 3,4-dimethyl-, (Z, Z) 9.08%. The main Syzygium aromaticum compounds are: 1,1,4,8-tetramethyl-cis, cis, 4,7,10-cycloundecatriene 28.74%, Caryophyllene oxide 25.34% and Eugenol 18.63%. The main compounds of Eucalyptus globulus are: Estragole 28.14%, Terpinolene 7.12% and 1,4-Hexadiene, 5-methyl-3-(1-methylethylidene) 7.01%. The insecticidal properties of the oils studied give an interesting anti-appetizing effect. A preliminary study showed that these oils have a high toxicity towards this insect. Published by Elsevier Ltd.