Western blacklegged tick (Ixodes pacificus) surveillance

Surveillance for Ixodes pacificus and pathogens found in this tick species in the United States. [PDF – 30 pages] Print only

To access the data used for this dashboard go to data sets.

Western blacklegged tick (Ixodes pacificus) lifecycle

Ixodes pacificus typically lays eggs in the spring. These hatch into larva in the following spring. During the summer, larvae feed and then molt into nymphs the following spring. During the summer, nymphs feed and then molt into adults over the winter. Adults females will seek a winter or spring blood meal before laying eggs in spring, completing the lifecycle.

The lifecycle of Ixodes pacificus ticks generally lasts three years. During this time, they go through four life stages: egg, larva, nymph, and adult. After the eggs hatch, the ticks must have a blood meal at every stage to survive. Blacklegged ticks can feed from mammals, birds, reptiles, and amphibians. The ticks need a new host at each stage of their life.