Hard ticks (Ixodidae) play a critical role in transmitting various tick-borne diseases (TBDs), posing significant global threats to human and animal health. Climatic factors influence the abundance, diversity, and vectorial capacity of tick vectors. It is imperative to have a comprehensive understanding of hard ticks, pathogens, eco-epidemiology, and the impact of climatic changes on the transmission dynamics of TBDs. The distribution and life cycle patterns of hard ticks are influenced by diverse ecological factors that, in turn, can be impacted by changes in climate, leading to the expansion of the tick vector’s range and geographical distribution. Vector competence, a pivotal aspect of vectorial capacity, involves the tick’s ability to acquire, maintain, and transmit pathogens. Hard ticks, by efficiently feeding on diverse hosts and manipulating their immunity through their saliva, emerge as competent vectors for various pathogens, such as viruses, parasites and bacteria. This ability significantly influences the success of pathogen transmission. Further exploration of genetic diversity, population structure, and hybrid tick vectors is crucial, as they play a substantial role in influencing vector competence and complicating the dynamics of TBDs. This comprehensive review deals with important TBDs in India and delves into a profound understanding of hard ticks as vectors, their biology, and the factors influencing their vector competence. Given that TBDs continue to pose a substantial threat to global health, the review emphasizes the urgency of investigating tick control strategies and advancing vaccine development. Special attention is given to the pivotal role of population genetics in comprehending the genetic diversity of tick populations and providing essential insights into their adaptability to environmental changes.

Hard ticks are important vectors for several human and zoonotic pathogens, transmitting diseases such as Crimean–Congo hemorrhagic fever, Lyme disease, Kyasanur forest disease, Powassan virus disease, Tick-borne encephalitis, Rickettsiosis, and Anaplasmosis. Morphological identification of ticks relies on taxonomic keys but is often challenging due to damaged, engorged, or immature specimens and requires expertise. Molecular taxonomy can be a supplement to species identification and usually requires nucleotide sequencing of the genetic markers. PCR-RFLP is an important tool for tick identification and can be supplemented to the classical taxonomy. The current study focused on the morphological identification of important hard tick vectors from India, their phylogenetic positioning, and developing a PCR-RFLP based diagnostic tool for easy identification of hard tick vectors. The primer sets were designed to amplify the ITS-2 region from important tick vectors causing human and zoonotic diseases in India. These ticks were morphologically identified with taxonomical keys, and the extracted genomic DNA were used for ITS-2 based PCR amplification. The nucleotide sequences from each vector were used for their phylogenetic positioning. We obtained variable sizes of ITS-2 amplicons from each species and utilized the sequence for RFLP assays design. We have successfully shown PCR-RFLP based assays with two different restriction enzymes (Hae III & Rsa I) with specific restriction sites on the amplified regions. The PCR-RFLP tool showed different DNA fragment patterns on the agarose gel, specific for each hard tick vector. This study presents the phylogenetic positioning of Indian tick vectors and demonstrates the development and applicability of a molecular tool for their identification.