Several tick species spread diseases to humans, including American dog ticks (Dermacentor variabilis), blacklegged ticks (Ixodes scapularis), western blacklegged ticks (Ixodes pacificus), and lone star ticks (Amblyomma americanum). With international trade transporting arthropods among continents, warming temperatures expanding habitable ranges, changes in land use, and increases in host populations, invasive tick species are a growing problem in North America. And, when invasive tick species do become established, they raise the concern of spreading diseases to humans, pets, and livestock. Over 100 tick species from other countries have arrived in the continental U.S. already.