Introduction to Ticks and Their Resistance to Acaricides

This chapter describes the significant economic and health challenges posed by ticks of the genus Ixodidae, particularly Rhipicephalus species, infesting livestock in tropical and subtropical regions and worldwide. It addresses the limited understanding of tick-borne diseases caused by hemoparasites, bacteria, and protozoa. These pathogens, transmitted through the bite of an infected vector tick, infect animals and occasionally humans, leading to morbidity and mortality and significant economic losses. It elaborates on the available tick control strategies using acaricides and its environmental repercussions. The increasing resistance to chemical treatments, categorized into acquired, cross-, and multiresistance, is discussed. The intricate process of evolution of resistance to acaricides, influenced by intrinsic and extrinsic factors, including tick genetics and environmental issues, is also examined. Moreover, various resistance mechanisms against commonly used acaricides are outlined, including organochlorines, organophosphates, carbamates, amidines, pyrethrins/pyrethroids, and macrocyclic lactones. The chapter suggests integrated management strategies encompassing rational acaricide use, vaccination, nutritional management, and the utilization of natural products. It also emphasizes the importance of genetic resistance in livestock breeds, environmental management, and diagnostic resistance tests. Lastly, it highlights the potential of PCR-based assays for rapid and specific resistance detection, aiding in the selection of effective acaricides.