Chemical composition and fumigant acaricidal activity of Salvia officinalis essential oil against Rhipicephalus...

Ticks are major ectoparasites of livestock worldwide, causing severe economic losses through blood feeding, reduced productivity, and the transmission of several diseases. The intensive use of synthetic acaricides has led to resistance in tick populations and raised concerns about environmental contamination and animal health. Consequently, there is increasing interest in plant-derived products as safer and more sustainable alternatives for tick management. This study investigated the chemical composition and fumigant acaricidal activity of Salvia officinalis essential oil against the tick Rhipicephalus microplus (Acari: Ixodidae). A total of 36 compounds were identified by gas chromatography coupled with mass spectrometry (GC-MS). The major constituents were dextro-camphor (26.90%), linalool (20.85%), and eucalyptol (20.37%), indicating a predominance of oxygenated monoterpenes. The essential oil exhibited marked fumigant toxicity against adult ticks under laboratory conditions. The median lethal concentration (LC₅₀) values were 3.19 and 1.89 µL L^-¹ air after 12 h and 24 h of exposure, respectively. The median lethal time (LT₅₀) ranged from 26.31 h at the lowest concentration (1.66 µL L^-¹ air) to 1.50 h at the highest concentration (26.66 µL L^-¹ air), showing a clear dose- and time-dependent effect. These findings suggest that S. officinalis essential oil could be a promising botanical fumigant for controlling R. microplus, with potential applications in integrated tick management strategies.