Southern tick species infestation in newly established wild boar and indigenous Japanese black bears in Yamagata Prefecture, northern Japan

Recently, a growing concern has been observed regarding the increasing incidences of tick-borne infectious diseases and expansion of the endemic areas in multiple locations worldwide. In the Japan Sea coast area of Tohoku region, the establishment of wild boar over several years, alongside potential increases in the Japanese black bear, have raised concerns about tick community change. However, data on tick infestations of wildlife in this area remain limited. Therefore, this study explored tick infestations on newly established wild boar and indigenous Japanese black bears in the area, with ticks collected from one wild boar and three Japanese black bears captured for agricultural and human health protection in Tsuruoka City, Yamagata Prefecture. Results revealed adult Amblyomma testudinarium infesting wild boar as well as several adult Dermacentor bellulus infesting wild boar and Japanese black bears. Dermacentor bellulus was the predominant tick species on both host species in the current study. These findings highlight the role of newly established wild boar and indigenous Japanese black bears as hosts of southern tick species in the Japan Sea coast area of Tohoku region. Further research is necessary to determine contemporary changes in tick community and the associated risks of tick-borne diseases this area.