Chemical composition and insecticidal activity of essential oils from cultivated and native aromatic plants of Argentina against Carpophilus dimidiatus (Fabricius) (Nitidulidae) and Oryzaephilus mercator (L.) (Silvanidae).

Essential oils from aerial parts of six aromatic plants were analysed by GC-MS. The major compounds identified were γ -terpinene (11.5%), cuminaldehyde (26.6%) and γ -terpinen-7-al (40.6%) in Cuminum cyminum , trans -anethol (95.2%) in Pimpinella anisum , α-pinene (11.6%), limonene (21.0%), β-caryophyllene (22.3%) and α-humulene (16.7%) in Lippia integrifolia , limonene (40.8%) and artemisia ketone (19.3%) in Lippia junelliana , trans -β-ocimene (15.6%), 4-ethyl-4-methyl-1-hexene (24.5%), trans -tagetone (20.5%) and verbenone (27.2%) in Tagetes minuta , 1,8-cineole (17.9%),elixene (10.3%) and spathulenol (13.8%) in Aloysia gratissima . Oils with strong insecticidal activity on Carpophilus dimidiatus and Oryzaephilus mercator were from P. anisum (LC ₅₀ = 4 µl/L; LC ₁₀₀ = 10 µl/L) and T. minuta (LC ₅₀ =10.19-12.57 µl/L; LC ₁₀₀ =20 µl/L). Scents of C. cyminum and L. junelliana were strong insecticides on O. mercator (LC ₅₀ =7.02-7.17 µl/L; LC ₁₀₀ =10.00-20.00 µl/L). The insecticidal activity was associated to the whole content of C10 molecules and oxygenated constituents. The P. anisum oil is promising as protective agent of nut products.