A Review of Acaricides and Their Resistance Mechanisms in Hard Ticks and Control Alternatives with Synergistic Agents.

Ticks are significant ectoparasites that transmit a variety of pathogens, leading to serious human and animal diseases, including Lyme disease, Rocky Mountain spotted fever, anaplasmosis and many others. The emergence of acaricide resistance in hard ticks presents a formidable challenge for public health and livestock management, exacerbated by the increasing incidence of tick-borne diseases and associated economic losses, estimated at $20 billion annually in the livestock sector alone. This review examines the mechanisms underlying acaricide resistance, focusing on genetic mutations, metabolic detoxification processes, and behavioral adaptations in tick populations. We detail the role of commercial acaricides in tick control while emphasizing the adverse effects of their overuse, which contributes to the development of resistant strains. Innovative control strategies are explored, including using pesticide synergists that enhance the efficacy of existing acaricides by targeting the tick's phosphagen system. Additionally, this review highlights the importance of understanding the synergistic interactions between various control methods, including non-chemical approaches such as personal protection measures and landscape management. The review concludes by underscoring the urgent need for novel acaricides with new modes of action and implementing regular monitoring practices to combat acaricide resistance effectively. Addressing these challenges is vital for the sustainable management of tick populations and protecting public health and livestock productivity.