This species replaces the Deer Tick (I. scapularis) in the western U.S. and western Canada. It is the principal vector of Lyme Disease in the west and may be found in most habitats, including forested areas where it often will be on moss-covered trunks of trees, in scrub areas, grasslands, and high brush. It is active throughout the year where the temperatures are mild and may spread Lyme Disease in the winter as well as the summer. Early stages feed on smaller vertebrates that are close to the ground, such as lizards and small rodents, while adults feed on larger animals such as deer, coyotes, livestock, and humans. The much lower incidence of Lyme Disease in the west is thought to be tied to the feeding on fence lizards, which may have an ability to kill the bacterium and prevent it from being moved from these animals. This is a 3-host tick that requires 2 to 3 years to complete its development from egg to adult.
Tick management relies on managing the environment to discourage ticks. This includes keeping grasses mowed short and eliminating rodents that may be nesting on the property and serving as alternate host animals. Excluding larger animals from a property also can reduce the number of ticks present. Pet owners need to be educated on inspecting pets daily for ticks and on the proper way to remove and dispose of ticks. Exterior areas where ticks are present can be treated with a labeled insecticide residual and interior areas also treated carefully. This should involve thorough crack and crevice applications into all possible crevices where the engorged ticks may have secluded themselves following feeding.