Composition and acaricidal activity of Laurus novocanariensis and Laurus nobilis essential oils against Psoroptes cuniculi

The major components of Laurus nobilis and L. novocanariensis leaf oils were identified and their acaricidal activity against Psoroptes cuniculi evaluated. Monoterpenes were predominant in L. nobilis oil (91.8%), while sesquiterpenes were only 1.4%. The main components of this oil were 1,8-cineole (39.2%), alpha-terpinyl acetate (11.3%), sabinene (10.6%) and linalool (7.4%). The acaricidal activity of L. nobilis oil, at a concentration of 10%, led to a mortality rate of 73%; at 5% the average activity was significantly reduced to 51%, while dilutions of 2.5%, 1.25% and 0.625% were ineffective. Laurus novocanariensis oil, compared to L. nobilis, was richer in sesquiterpenes; the main constituents were alpha-pinene (10.4%), 1,8-cineole (9.6%) and beta-selinene (7.2%). After 24 h of contact, the oil of L. novocanariensis killed all the mites when used at 10% and 5% concentrations. At lower concentrations the mortality significantly decreased; a dilution of 0.625% was ineffective.