Species distribution modeling of the castor bean tick, Ixodes ricinus (Linnaeus, 1758), under current and future climates, with a special focus on Ukraine and Latvia

This study assesses the impact of climate change on the distribution of Ixodes ricinus ticks, that is transmitting Lyme disease, a growing public health concern. Utilizing ensemble models from the R package flexsdm and climate data from WorldClim, ENVIREM, and CliMond, we project habitat suitability changes for the focus species. The models, validated against Lyme disease incidence rates, predicted a 1.5-fold increase in suitable habitats in Latvia opposite to a 4.5-fold decrease in suitable habitats within Ukraine over the coming decades. SHAP values were analyzed to determine the most influential climatic features affecting tick distribution, providing insights for future vector control and disease prevention strategies: here name the drivers in decreasing order. This implies an increased presence of ticks in Scandinavian countries (Sweden, Norway, Finland), Baltic states (Estonia, Latvia, Lithuania), Denmark, and Belarus. These findings largely coincide with our projections regarding bioclimatic suitability for ticks in Ukraine and Latvia. These shifts reflect broader patterns of vector redistribution driven by global warming, with potential expansions in higher altitudes and latitudes. Our findings highlight the urgent need to adapt public health planning to the evolving landscape of vector-borne diseases under climate change.