Effects of Rosmarinus officinalis and Salvia officinalis essential oils on Tetranychus urticae Koch (Acari: Tetranychidae)

Laboratory trials were carried out to characterize Rosmarinus officinal and Salvia officinalis essential oils and to evaluate their pesticidal activities against Tetranychus urticae. Slide-dip and leaf-disk bioassays were employed to study the mortality caused by these plant oils on two-spotted spiders. Different dilutions of both essential oils (0.10-0.25%, v/v) caused acute contact toxicity, although the sage extract showed greater acaricidal activity than rosemary oil. Mortality rates of 95-100% were observed at all the sage oil dosages and when rosemary emulsions contained at least 0.20% of essential oil. In the residual contact experiments (leaf-disk assays), 0.15-0.25% of sage oil or …