Biocidal Potential and Chemical Composition of Industrial Essential Oils from Hyssopus officinalis, Lavandula x intermedia var. Super, and Santolina chamaecyparissus

This work presents the biocidal (insecticidal, ixodicidal, nematicidal, and phytotoxic) effects and chemical compositions of three essential oils obtained from the industrial steam distillation (IEOs) of hyssop (Hyssopus officinalis L.), lavandin (Lavandula x intermedia or L. x hybrida var. Super), and cotton lavender (Santolina chamaecyparissus L.). Their chemical composition analyzed by gas chromatography coupled to mass spectrometry showed 1,8-cineole (53%) and -pinene (16%) as the major components of H. officinalis, linalyl acetate (38%) and linalool (29%) of L. x intermedia; and 1,8-cineole (10%) and 8-methylene-3-oxatricyclo[5.2.0.0(2,4)]nonane (8%) in S. chamaecyparissus. The biocidal tests showed that L. x intermedia IEO was the most active against the insect Spodoptera littoralis and toxic to the tick Hyalomma lusitanicum, IEO of H. officinalis was strongly active against S. littoralis, and finally, S. chamaecyparissus IEO was a strong antifeedant against the aphid Rhopalosiphum padi, toxic to H. lusitanicum and with moderate effects against Leptinotarsa decemlineata, S. littoralis, and Lolium perenne.