Integrative morpho-molecular delineation of five medically significant tick species: facilitating precision-based vector surveillance.

Abstract

Ticks serve as major vectors of zoonotic pathogens, posing significant threats to public health and livestock. However, morphological similarity among closely related species complicates accurate identification. This study employed an integrative taxonomic approach combining morphological and molecular methods to delineate five medically important tick species in Xinjiang, China. From April to July 2024, a total of 1,128 ticks were collected from livestock across four ecological regions (Ürümqi, Turpan, Jimsar, and Aksu). Morphological features-including basis capituli, scutum, and genital aperture-were analyzed via stereomicroscopy, while molecular characterization targeted mitochondrial (16S rDNA, COI) and nuclear (ITS2) markers. Phylogenetic trees were reconstructed using the maximum likelihood method. Morphological identification confirmed five species:, and, supported by high-resolution imaging. Molecular data revealed notable interregional genetic affinities:from Turpan shared COI similarity with strains from Kazakhstan;from Turpan clustered with Iranian populations;from Jimsar showed 16S rDNA similarity to Saudi Arabian lineages;from Aksu grouped with Egyptian COI sequences; andfrom Jimsar aligned with populations from Alashankou, China. Notably, single-gene phylogenies posed taxonomic limitations-for example, ITS2 misclassifiedas. These issues were mitigated through morphological diagnostics such as scutal enamel spots inand the distinctive genital plates in. The integrative approach improved taxonomic resolution, with 16S rDNA providing genus-level insight, COI enabling species-level discrimination, and ITS2 offering strain-level resolution. Additionally, high-resolution morphological imaging addressed gaps in existing reference databases. Overall, multi-locus strategies combined with morphological validation are essential for accurate tick identification, improving our capacity to monitor vector-borne pathogen transmission and contributing to One Health surveillance frameworks.