Tick species identification

Western blacklegged tick

What to look for

Dark legs and a reddish-brown body without ornate white markings; closely resembles the eastern blacklegged tick.

Western blacklegged tick photo

Compare more than color alone. Sex, life stage, feeding, angle, and lighting can change what the markings look like.

Adult western blacklegged tick with black legs and a reddish-brown body on a leaf — Adult female. Nearly identical to the eastern blacklegged tick; location is the main clue. Photo: Kaldari, CC0.

Known disease associations

— Lyme disease
— Anaplasmosis
— Borrelia miyamotoi disease

Finding this species does not mean the tick carried a pathogen or that transmission occurred.

Photos need context

Feeding, life stage, image angle, and damage can change how a tick looks. A useful identification weighs several visible traits together and states uncertainty when the photo does not show enough detail.

References: CDC tick information.