| ixodes pacificus | (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, Syn. western black-legged tick |
| ixodes scapularis | (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), Syn. black-legged tick |