Rhipicephalus microplus (Acari: Ixodidae), is a major ectoparasite causing substantial economic loss to the livestock industry particularly, in the tropical and sub-tropical regions. Although, it primarily parasitizes cattle and other bovids, a variety of other domestic as well as wild animals can also be infested. Its one-host life cycle, requiring three consecutive blood meals from a single host imposes a heavy physiological burden on the animals. Infestations result in direct losses including blood depletion, reduced milk production and hide damage as well as indirect impacts through the transmission of pathogens such as Babesia species and Anaplasma marginale (Oyen and Poh, 2025). These infections collectively cause high morbidity, reduced productivity and mortality in the affected herds (Guerrero et al., 2014). In India, the estimated annual economic loss due to tick and tick-borne diseases exceeds 787.63 million USD (Singh et al., 2022), with similar patterns reported across Latin America, Africa and Southeast Asia (Grisi et al., 2014; Lew-Tabor and Valle, 2016; Rodríguez-Vivas et al., 2017). Additionally, expanding trade and climate change have facilitated the spread of R. microplus, heightening the threat of tick-borne diseases in previously unaffected areas. Given its economic and health impacts, effective tick control remains critical for ensuring sustainable livestock production.

Effective tick control typically necessitates a multifaceted strategy integrating chemical, immunological and management approaches. Among these, use of synthetic acaricides including organophosphates, carbamates, synthetic pyrethroids, phenylpyrazoles, isoxazolines, formamidines and macrocyclic lactones remains the predominantly adopted method worldwide, largely due to their rapid action and broad-spectrum effectiveness (FAO, 2025). However, heavy reliance on synthetic acaricides has led to the widespread selection of resistance including emergence of multi-acaricide resistant R. microplus populations (Singh et al., 2019). This multi-acaricide resistance not only limits the effectiveness of conventional treatments but also increases input costs for farmers and raises the concerns over environmental and food safety. As a result, there is growing interest in identifying the alternative, sustainable tick control strategies that can be integrated into existing tick management programs.

Among the various alternative approaches, plant-derived compounds, particularly, essential oil components (EOCs) are increasingly being explored for their acaricidal potential. The EOCs offer several advantages including diverse bioactivity, natural origin and and high effectiveness (Benelli and Pavela, 2018). Moreover, they provide consistent chemical profiles thereby improving reliability of their biological effects when compared to essential oils (EOs) which are chemically complex and can exhibit batch-to-batch variability (Rosado-Aguilar et al., 2017). However, despite their acaricidal potential, most recent studies have primarily focused on EOs but the systematic comparative evaluation of acaricidal efficacy of the individual EOCs against R. microplus under standardized conditions remains limited.

Therefore, the present study was planned with an objective to evaluate the acaricidal activity of six selected EOCs against acaricide-resistant R. microplus population to address this research gap. The test compounds included three monoterpenes (menthol, citral and limonene), two phenylpropanoids (eugenol and cinnamaldehyde) and one sesquiterpene (cedrol). The selection of these components was based on prior evidence of bioactivity of EOs reported in our earlier studies (Jyoti et al., 2019; Vangchhia et al., 2024) and other reports highlighting their acaricidal potential (Lima et al., 2016; Marchesini et al., 2021; Flor-Weiler et al., 2022; Gonzaga et al., 2023; Oliva Chávez et al., 2023; Ferreira et al., 2024). By comparing the acaricidal responses of these EOCs, this research seeks to identify promising candidates for further development of eco-friendly alternatives to the synthetic acaricides, contributing towards sustainable and integrated tick management (ITM) strategies.