Salvia rosmarinus Spenn. ‘Eretto Liguria’ is a regional rosemary ecotype from northwestern Italy with potential for sustainable pest control. This study aimed to characterize the essential oil (EO) and evaluate its bioinsecticidal activity against the tomato leaf miner (Tuta absoluta Meyrick), a major pest responsible for the destruction of tomato crops. The EO obtained from the fresh aerial parts was analyzed by GC-MS, and laboratory bioassays were conducted to measure larvicidal, antifeedant, and acetylcholinesterase (AChE) inhibitory activities at concentrations ranging from 0.05% to 5.0% (v/v). 29 constituents were identified, with α-pinene (29.40%), camphene (8.47%), β-myrcene (7.45%), and 1,8-cineole (6.19%) as the main volatile molecules of S. rosmarinus EO. Biological assays showed strong dose and time-dependent toxicity, resulting in 100% larval mortality at 2.5–5.0% within 72 h. The LC50 value decreased from 1.410% at 24 h to 0.384% at 72 h, while the FI50 value was 0.363% (v/v) at 72 h. Furthermore, an AChE inhibition was observed, with an IC50 of 10.32% (v/v), and in silico investigations suggested that α-pinene, β-myrcene, limonene, linalool, and bornyl acetate were the main potential enzyme inhibitors. No phytotoxicity was observed on tomato plants at the tested doses. Overall, these results demonstrate that S. rosmarinus EO is a promising, environmentally friendly approach for integrated pest management against T. absoluta.
Vetere et al. (Mon,) studied this question.