Morpho-molecular characterization of tick species prevalent in domesticated and semi-domesticated bovine species in three districts of Arunachal Pradesh.

Ticks are small, blood-sucking arthropods that pose a significant threat to public health and animal welfare worldwide. However, information on the relationships between tick species diversity, altitudinal gradients and hosts in Arunachal Pradesh is limited. This study investigates tick prevalence across five locations in Arunachal Pradesh, India, at altitudes ranging from 140 m to 1200 m. Scanning electron microscopy (SEM) and sequencing of the mitochondrial 16S ribosomal RNA gene (rRNA) and nuclear second internal transcribed spacer (ITS2) were used for morpho-molecular identification of tick species. Morphological and molecular phylogenetic analyses confirmed the presence of tick species: Rhipicephalus microplus, Amblyomma integrum, Haemaphysalis longicornis, Haemaphysalis bispinosa and Ixodes ovatus. This study provides the first report on the ITS2 gene sequence and phylogenetic analysis of A. integrum. Among the tick species, R. microplus emerged as the most dominant tick species across all altitudes and seasons in the study areas. Host-specific observations showed that Bos frontalis hosted a larger variety of ticks compared to Bos indicus in most locations. This study describes the use of SEM and 16S rRNA/ITS2-based molecular analysis for tick species identification and highlights the seasonal predominance and species richness of ticks across different altitudes and hosts.