Species diversity of tick and tick-borne pathogens from roe deer (), including new record of (Acari: Ixodidae), in Jeju Island, Republic of Korea.

Hard ticks (Ixodidae family) are primary vectors of zoonotic diseases, including severe fever with thrombocytopenia syndrome (SFTSV), anaplasmosis, babesiosis, Lyme borreliosis, and ehrlichiosis. The roe deer (), a key host for tick-borne diseases, is widely distributed on Jeju Island, Republic of Korea (ROK). Although the increased interactions between deer, livestock, and humans have raised concerns about zoonotic disease transmission, this area has remained understudied. Therefore, this study aimed to investigate the species diversity of ticks infesting roe deer and the prevalence of major tick-borne diseases in this region. From 2018 to 2020, 1832 ticks were collected from 154 roe deer. Four tick species were identified: (50.1 %), . (47.9 %), (1.7 %), and . (0.3 %). This study reports the first detection of in the ROK. Pathogen screening detected spp. (minimum infection rate, MIR: 0.38 %), spp. (0.05 %), and spp. (0.44 %); however, sequencing was only successful for spp. These findings highlight the importance of continued tick surveillance and research on the zoonotic risks associated with emerging tick species in the ROK.