Climate change influences on the geographic distributional potential of the spotted fever vectorsAmblyomma maculatumandDermacentor andersoni

Abstract

Amblyomma maculatum(Gulf Coast tick), andDermacentor andersoni(Rocky Mountain wood tick) are two North American ticks that transmit spotted fevers associatedRickettsia.Amblyomma maculatumtransmitsRickettsia parkeriandFrancisella tularensis, whileD. andersonitransmitsR. rickettsii,Anaplasma marginale,Coltivirus(Colorado tick fever virus), andF. tularensis. Increases in temperature causes mild winters and more extreme dry periods during summers, which will affect tick populations in unknown ways. Here, we used ecological niche modeling (ENM) to assess the potential geographic distributions of these two medically important vector species in North America under current condition and then transfer those models to the future under different future climate scenarios with special interest in highlighting new potential expansion areas. Current model predictions forA. maculatumshowed suitable areas across the southern and Midwest United States, and east coast, western and southern Mexico. ForD. andersoni, our models showed broad suitable areas across northwestern United States. New potential for range expansions was anticipated for both tick species northward in response to climate change, extending across the Midwest and New England forA. maculatum, and still farther north into Canada forD. andersoni.