(the rotund tick)
This hard tick occurs throughout western North America and occasionally in the east. Its distribution in the USA includes AZ, CA, CO, IA, ID, KS, MI, MS, MT, NC, ND, NE, NM, NV, OK, OR, SD, TX, UT, and WY; collections in the eastern USA (GA, MD, and OH) are dubious. In Canada, it occurs in Alberta, British Columbia, Manitoba, and Saskatchewan. It is commonly found in prairie habitats, but may also occur in shrubland and forested habitats.
This species has a wide range of host associations: 19 species of carnivores including domestic dogs and cats, weasels, and American badgers; 40 species of rodents; 5 species of lagomorphs; and humans. Differences in morphometrics have been found in host associations in areas west and east of the Rocky Mountains with smaller ticks from gophers, kangaroo rats, and sigmodontine mice in areas west, and larger ticks from carnivores (including domestic dogs and cats), ground squirrels, and prairie dogs in areas east.
The agents of Q fever, tularemia, and Colorado Tick Fever Virus have been isolated from this tick species.
H Joel Hutcheson, James W Mertins, Boris C Kondratieff, Monica M White, Ticks and Tick-Borne Diseases of Colorado, Including New State Records for Argas radiatus (Ixodida: Argasidae) and Ixodes brunneus (Ixodida: Ixodidae), Journal of Medical Entomology, tjaa232, https://doi.org/10.1093/jme/tjaa232