Dermacentor variabilis

[vär′ē-ābə-lĭs]
n.
  1. A tick that transmits tularemia and is the principal vector of Rocky Mountain spotted fever in the central and eastern US; the American dog tick.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.