Ecological niche and potential geographic distributions of Dermacentor marginatus and Dermacentor reticulatus (Acari: Ixodidae) under current and future climate conditions

Abstract. Dermacentor marginatus is a vector disease of both humans and animals and transmits the causative agents of Q fever (Coxiella burnetii) and the spotted fever group (Rickettsia raoultii and R. slovaca), as well as of Crimean–Congo hemorrhagic fever. Dermacentor reticulatus can transmit various pathogens such as Francisella tularensis, Babesia spp., tick encephalitis virus, Coxiella burnetii, Omsk hemorrhagic fever virus, and Rickettsia spp. and can cause serious skin lesions. Herein, ecological niche modeling (ENM) is used to characterize the niches of these two ticks and describe their potential distributional patterns under both current and future climate conditions, as a means of highlighting geographic distributional shifts that may be of public health importance. We assessed distributional implications of five general circulation models (GCMs), under two shared socio-economic pathways (SSP245 and SSP585) for the period 2041–2060. Predictions for D. marginatus showed broad suitable areas across western, central, and southern Europe, with potential for expansion in northern and eastern Europe. Dermacentor reticulatus has suitable areas across western, central, and northern Europe. Under future scenarios, new expansions were observed in parts of northern and eastern Europe and highland areas in central Europe. Despite broad overlap between the niches of the ticks, D. marginatus has a broader niche, which allows it to show greater stability in the face of the changing climate conditions. Areas of potential geographic distributional expansion for these species should be monitored for actual distributional shifts, which may have implications for public health in those regions.