Tick Identification Chart: Common U.S. Ticks

Ixodes scapularis

Blacklegged (deer) tick

Markings

Small, reddish-brown to black, with no ornate white markings. Unfed nymphs can be about the size of a poppy seed.

Range

Eastern and central United States

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Photo: Scott Bauer, USDA ARS, public domain. Adult female. Black legs and shield over an orange-red body.

Ixodes pacificus

Western blacklegged tick

Markings

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

Range

Pacific Coast, especially northern California

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Photo: Kaldari, CC0. Adult female. Nearly identical to the eastern blacklegged tick; location is the main clue.

Amblyomma americanum

Lone star tick

Markings

Reddish-brown. Adult females usually have one distinct pale dot on the back; adult males have pale markings around the body edge.

Range

Southern, eastern, and midwestern United States

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Photo: James Gathany, CDC PHIL #4407, public domain. Adult female. The single white dot on the back is the classic field mark.

Dermacentor variabilis

American dog tick

Markings

A larger brown tick with mottled cream or gray markings on the shield behind the mouthparts.

Range

Widely distributed east of the Rocky Mountains and in parts of the Pacific Coast

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Photo: U.S. Fish and Wildlife Service, public domain. Adult male and female. The male is above; the female is below.

Dermacentor andersoni

Rocky Mountain wood tick

Markings

Brown with ornate pale markings; adults resemble American dog ticks, making geography and close dorsal photos important.

Range

Rocky Mountain states and southwestern Canada

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Photo: James Gathany, CDC PHIL #10865, public domain. Adult female. A pale ornate shield over a reddish-brown body, much like the American dog tick.

Rhipicephalus sanguineus

Brown dog tick

Markings

Uniform reddish-brown without ornate markings; has a narrow, elongated body and is strongly associated with dogs and kennels.

Range

Worldwide, often in and around buildings where dogs live

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Photo: @dineshphotography7797, CC BY 4.0. Adult. Reddish-brown without the ornate pale markings of an American dog tick. Resized and converted to WebP.

Amblyomma maculatum

Gulf Coast tick

Markings

Long mouthparts and ornate pale markings; adults are often found on larger animals and people.

Range

Atlantic and Gulf Coast states, with an expanding inland range

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Photo: Christopher Paddock and James Gathany, CDC PHIL #10878, public domain. Adult male. Ornate pale lines cover the back; note the long mouthparts at the front.