The incidence and spread of tick-borne diseases such as Japanese spotted fever and SFTS are increasing. Particularly in 2025, numerous cases were reported in the Kanto region, challenging the previous understanding that outbreaks were primarily concentrated in western  part of Japan. The expansion of endemic areas is suspected to be linked to changes in the habitat of the vectors, ticks, as well as shifts in the distribution of reservoir wildlife. Specifically, the three species Amblyomma testudinarium, Haemaphysalis flava, and Haemaphysalis longicornis account for a high number of tick-bite cases in humans and domestic animals in Japan. Distribution information for these ticks is essential for assessing tick-borne disease risks.
This study constructed species distribution models using collection site data and background data (land use, wildlife distribution, climatic information) from 2015 to 2025 to estimate current distributions. Furthermore, using background data from the 1970s and background data for the 2050s which is estimated based on climate change models (CDFDM method using CMIP6), we estimated the historical, current, and future tick distribution and their range shift through the time phases. We report key factors for each tick species. Based on estimated distributions and associated landscape and wildlife information, the ecology of vector ticks will be discussed. This information aims to alert individual researchers in fields. Furthermore, the study suggests and discusses the social implementation of risk management methods and barrier against the application.