The Black-legged tick (deer tick) I. scapularis is found in eastern North America including the New England, mid-Atlantic, southeastern states, and the midwestern states of Minnesota and Wisconsin. It has been observed in Michigan, Iowa, Illinois, and Indiana.
Distribution of the tick is associated with high humidity and mild mean winter temperatures. However, it is not restricted by winter temperatures as areas of tick activity occur in Minnesota and Wisconsin. The requirement for high humidity restricts this tick from spreading to arid areas and high mountains where desiccation is a limiting factor.
- Sonenshine DE: Biology of Ticks. Part 1, 1991, Oxford University Press, New York