Toxicity of Essential Oils of Origanum vulgare, Salvia rosmarinus, and Salvia officinalis Against Aculops lycopersici

The tomato russet mite (TRM), <i>Aculops lycopersici</i>, is a destructive pest of tomato crops worldwide. It poses a significant challenge to growers in both greenhouse and open-field conditions. Traditional chemical control methods are often ineffective, promote resistance, and have negative environmental impacts. This has prompted the search for alternative strategies, such as biological control and eco-friendly botanical pesticides. In this study, we evaluated the acaricidal effects of essential oils (EOs) extracted from three officinal plants, <i>Origanum vulgare</i> L., <i>Salvia rosmarinus</i> Spenn., and <i>Salvia officinalis</i> L., cultivated using precision aromatic crop (PAC) techniques. Their efficacy was evaluated against <i>A. lycopersici</i> under laboratory conditions. The chemical composition of the EOs was determined by solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The dominant component of <i>O. vulgare</i> EO was carvacrol (83.42%), followed by ρ-cymene (3.06%), and γ-terpinene (2.93%). In <i>S. rosmarinus</i>, α-pinene (28.0%), 1,8-cineole (11.00%), and borneol (7.72%) were the major components. <i>S. officinalis</i> EO was characterized by high levels of 1,8-cineole (27.67%), camphor (21.91%), and crisantenone (12.87%). We tested multiple concentrations (320-5000 μL L-¹) and exposure times (1-4 days) to assess mite mortality. The results revealed both dose- and time-dependent toxic activity, with significant differences among EOs. <i>O. vulgare</i> EO was the most toxic, causing 90% mortality at 0.5% (<i>w</i>/<i>v</i>) concentration after 4 days. <i>S. rosmatinus</i> and <i>S. officinalis</i> EOs had more limited effects, with 46% and 42% mortality, respectively. Lethal concentration (LC₅₀) values were 2.23 mL L-¹ (95% CI: 1.74-3.05) for <i>O. vulgare</i>, 5.84 mL L-¹ (95% CI: 3.28-22.29) for <i>S. rosmarinus</i>, and 6.01 mL L-¹ (95% CI: 2.63-261.60) for <i>S. officinalis</i>. These results indicate that <i>O. vulgare</i> EO shows efficacy comparable to commercially available botanical pesticides. Our findings support the potential of <i>O. vulgare</i> EO as a viable alternative for the control of <i>A. lycopersici</i>, contributing to integrated pest management (IPM) strategies.