Common Ticks

Western Black-legged Tick (Ixodes pacificus)

The Western Black-Legged Tick is a common tick found throughout the west coast of North America. This species of tick is a vector of both the Lyme disease spirochete and Equine Granulocytic Ehrlichiosis Rickettsia in California.

Immature stages (larvae and nymphs) feed mostly on lizards (e.g. Western Fence Lizard) and small rodents while the adults feed on large mammals such as deer, dogs, coyotes, horses and humans. This species is most active from late winter to summer, with the immature stages feeding primarily during the spring and summer months.

Pacific Coast Tick, (Dermacentor occidentalis)

This species is widely distributed throughout California except for the very arid areas of the central valley and south eastern desert region. It has also been found in Oregon and Baja California.

The immature stages feed on rodents, especially squirrels, while the adults prefer large mammals such as cattle, horses, deer and humans.

Brown Dog Tick, (Rhipicephalus sanguineus)

The Brown Dog tick is a widespread tick that is an important pest of dogs. This species feeds on dogs as a larva, nymph and adult. Within California it is most frequently encountered on dogs housed within dog kennels.

The Brown Dog Tick is known to vector Rocky Mountain Fever, canine ehrlichiosis and canine babesiosis.

American Dog Tick, (Dermacentor variabilis)

This tick is found throughout the United States as well as parts of Canada and Mexico. Within California it is most frequently found along the coastal ranges and central valley. This species is an important vector of Rocky Mountain Spotted fever rickettsia and the bacterium responsible for Tularemia. The saliva of this tick has also been known to cause tick paralysis.

The immature stages feed primarily on rodents, rabbits and hares, while the adults prefer large mammals, especially dogs, coyotes and humans.