How to identify a Western blacklegged tick
Ixodes pacificus
· Also called western deer tick, ixodes pacificus, california deer tick, lyme tick california
On the Pacific Coast, Lyme risk is Ixodes pacificus, the western blacklegged tick — a sister species to the eastern deer tick, not the ornate Pacific Coast tick.
Someone searching this page usually has a western blacklegged tick in a photo, on skin, or in a story about woods, coastal scrub, leaf litter. Use the marks, the bite, and the range together. On the Pacific Coast, Lyme risk is Ixodes pacificus, the western blacklegged tick — a sister species to the eastern deer tick, not the ornate Pacific Coast tick.
What does a western blacklegged tick look like?
Looks very like the eastern deer tick: black legs, unmarked dark scutum. Found west of the Rockies on trails through oak woodland and coastal forest. Larger ornate Dermacentor ticks in the same states are not the Lyme vector.
Western blacklegged tick (Ixodes pacificus) is Similar to the eastern deer tick; nymphs tiny. Colors people notice: black, dark brown, red. Field marks: Looks very like the eastern deer tick; Black legs, unmarked scutum; Found west of the Rockies; Often on trails through oak woodland or coastal forest. It is found outdoor. If those marks are missing, open Deer tick, Pacific Coast tick, American dog tick before you force this name. Search phrases that belong on this page include what a western blacklegged tick looks like and western blacklegged tick identification.
Identification marks
- Looks very like the eastern deer tick
- Black legs, unmarked scutum
- Found west of the Rockies
- Often on trails through oak woodland or coastal forest
Size: Similar to the eastern deer tick; nymphs tiny
Colors: black, dark brown, red
Where: outdoor
What a typical western blacklegged tick bite looks like
Small attachment red spot; possible expanding rash with Lyme. Same tweezer removal and 30-day watch as eastern deer ticks.
People searching “western blacklegged tick bite identification” want the pattern, not a single anonymous bump. Small attachment red spot; possible expanding rash with Lyme. Same watch-outs as eastern deer tick. Immediate steps on this page: Tweezers removal, clean, monitor 30 days; Discuss testing or treatment with a clinician if symptoms appear; Check clothing and pets after coastal or foothill hikes. This species does bite or sting people. Fever, spreading redness, trouble breathing, or a child with many stings is professional care.
If you were bitten
- Tweezers removal, clean, monitor 30 days
- Discuss testing or treatment with a clinician if symptoms appear
- Check clothing and pets after coastal or foothill hikes
Western blacklegged tick vs Deer tick
Western blacklegged tick looks like the eastern deer tick. Pacific Coast tick is larger and ornate (white on the shield). If you hiked oak woodland in California, the small unmarked Ixodes is the Lyme species.
- Deer tick identification (Ixodes scapularis)
- Pacific Coast tick identification (Dermacentor occidentalis)
- American dog tick identification (Dermacentor variabilis)
Range and season
California, Oregon, Washington, southern B.C. Nymphs often late winter–early summer in much of CA.
Pacific Coast trails, oak woodland, and coastal forest. Nymphs can be out in late winter in much of California.
Pacific Coast from British Columbia through California, with inland pockets. Lyme risk exists but is generally lower than in the Northeast.
Nymphs late winter–early summer in much of CA; adults cooler, wetter months
Common questions
Is the western blacklegged tick the same as the deer tick?
They are sister species. I. pacificus is the West Coast Lyme vector; I. scapularis is the East/Midwest vector.
Where is it found?
Primarily California, Oregon, Washington, and southern British Columbia.
When is Lyme risk highest in California?
Often late winter through early summer when nymphs are active, depending on the region.
What tick carries Lyme in California?
The western blacklegged tick (Ixodes pacificus), not the ornate Pacific Coast tick.
Is there Lyme disease in California?
Yes, via Ixodes pacificus, not the ornate Pacific Coast tick.
Western blacklegged tick vs Pacific Coast tick?
Ixodes: small, unmarked, dark. Dermacentor occidentalis: larger, white-marked scutum.