Evaluation of biological activities of two essential oils as a safe environmental bioinsecticides: case of Eucalyptus globulus and Rosmarinus officinalis

Abstract

All works of this article were conducted to investigate chemical composition and insecticidal and antimicrobial properties of Eucalyptus globulus and Rosmarinus officinalis essential oils isolated by hydro-distillation of its aerial parts. Analysis of the essential oils on the basis of gas chromatography and mass spectrometry (GC/FID and GC/MS) revealed the presence of 82 organic volatiles representing 98.63% of the total constituents of Eucalyptus globulus and the presence of 45 organic volatiles representing 98.53% of the total constituents of Rosmarinus officinalis. The major compounds for Eucalyptus globulus were estragole (28.14%), terpinolene (7.12%), 1,4-hexadiene-5-methyl-3-(1-methylethylidene) (7.01%), linalool (5.54%) and furfural (4.66%) and for Rosmarinus officinalis were (-)-camphor (31.16%) and β-caryophyllene (18.55%), 3,4-dimethyl-(Z,Z)-2,4-Hexadiene (9.08%), α-fenchene (4.67%), cis-verbenone (4.33%) and Bornyl acetate (3.4%). The efficacy of the two essential oils was evaluated on the insect pests Sitophilus granarius of wheat and was remarkable with lethal doses of 50% tending towards 1 μL·cm–3. The broth microdilution method as a complementary test was conducted to test the antimicrobial activity of the essential oil against: Staphylococcus aureus, Enterococcus faecium, Listeria monocytogenes, Bacillus subtilis, Escherichia coli, Yersinia enterocolitica, Pseudomonas aeruginosa and Candida albicans, further for the two oils of shows promising activity against all strains.