n a tick that feeds on dusky-footed wood rat and bites humans; principal vector for Lyme disease in western United States especially northern California
n parasitic on sheep and cattle as well as humans; can transmit looping ill in sheep (acute viral disease of the nervous system); a vector for Lyme disease spirochete
n parasitic on mice of genus Peromyscus and bites humans; principal vector for Lyme disease in eastern United States (especially New England); northern form was for a time known as Ixodes dammini (deer tick)