Lone Star tick (Amblyomma americanum)
The Lone Star tick (Amblyomma americanum) is a fast, aggressive tick that bites people. It lives across the eastern, southeastern, and south-central United States. The adult female is easy to spot. She has a reddish-brown body with one bright white or cream dot in the middle of her back (the "lone star"). Males, nymphs, and the tiny larvae do not have the dot, so it only helps you identify adult females. Unlike the blacklegged (deer) tick, the Lone Star tick does not spread Lyme disease. But it is the main US cause of alpha-gal syndrome, a red meat allergy. It can also spread ehrlichiosis, Heartland virus, Bourbon virus, and tularemia, and it is linked to the STARI rash. This page is for learning and does not replace medical care. See a doctor about any bite, rash, or symptoms.
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How to identify it
- Adult female: a reddish-brown body with one clear white or cream dot in the middle of the hard shield on her back (scutum). The dot can look a little shiny. This dot, the 'lone star', is what identifies her.
- Adult male: darker reddish-brown, with no single dot in the middle. Instead, he has scattered white spots and streaks around the rear and outer edge of his body.
- Long mouthparts (capitulum) that clearly stick out in front. They are much longer than the short mouthparts of Dermacentor 'dog' ticks. This is a useful clue on males, nymphs, and larvae, which lack the dot.
- Festoons: a row of small rectangular blocks, split by grooves, along the rear edge of the body. Nymphs and adults have them.
- Rounded, teardrop-shaped body and fairly long legs. The overall look is 'roundish', not the flat, narrow shape of a blacklegged tick.
- Nymphs and larvae have no markings and are easy to confuse with other species. The white dot does not apply to them.
Size by life stage
Larva (six legs, the "seed tick"): about 0.5 mm, like a pinhead or a grain of sand. Nymph (eight legs): about 1–1.5 mm, close to a poppy seed. Unfed adult: about 3–4 mm, like a sesame seed. The female is a little larger than the male. Fully fed (engorged) female: swells to about 10–16 mm, the size of a pea or small grape, and turns slate-gray or olive. Females may take a week to 10 days or more to finish feeding.
Where it lives and when
CDC maps the Lone Star tick as widespread in the Northeast, South, and Midwest of the United States. Its core range, where it has lived the longest, runs from Texas and Oklahoma east across the South-Central and Southeastern states to the Atlantic coast. From there it runs up the coastal plain into the mid-Atlantic and southern New England. Tracking data and university extension reports show it is still spreading north and west. It has been found as far north as Maine and as far west as parts of Colorado and Wyoming. The spread is partly linked to white-tailed deer numbers bouncing back. If a county is not marked "established", that does not mean the tick is absent there.
Season
Active from spring through fall, with a longer season in the warm South. Adults are most active from about April through late August. Nymphs are common from late spring into summer (about May–July). Larvae peak in mid-to-late summer. These are the swarming "seed ticks" that can attach by the dozens or hundreds. All three stages (larva, nymph, and adult) bite people. This tick actively seeks out a host and moves quickly toward it.
Where it waits
- Woods with thick, brushy undergrowth, and the shady edges where forest meets field
- Tall grass, weedy field borders, fence lines, and overgrown trail edges
- Around places where animals rest and bed down, especially where white-tailed deer and wild turkeys live
- Leaf litter and low plants in humid, shady ground cover
- Suburban yards and edges next to woods or brush where deer and small mammals travel
Diseases it can carry
Tick presence is not the same as personal disease risk. Not every bite transmits a pathogen.
Look-alikes
Mix-ups are common outside the adult female stage. The American dog tick (Dermacentor variabilis) is often confused with it. It is a similar size, but its shield has a mottled, marbled white-to-gray pattern instead of a single dot. Its mouthparts are also much shorter. The tell is the female Lone Star's one clean central dot versus the dog tick's patterned shield. The Gulf Coast tick (Amblyomma maculatum) is a close relative that shares parts of the Southeast. It is larger, with silvery markings spread across the shield instead of a single spot. Blacklegged (deer) ticks (Ixodes scapularis) are much smaller and darker, with no white dot. They are worth telling apart because people often fear Lyme, which the Lone Star tick does not spread. Male Lone Star ticks (streaks, not a dot) and all nymphs and larvae lack the star. So the classic marking only confirms adult females. For the other stages, use body shape, long mouthparts, and festoons. You can also photograph the tick or ask a doctor or extension service to identify it.
Compare all tick speciesCommon questions
What does a Lone Star tick look like?
It is reddish-brown, and the adult female has one white dot. The dot is bright white or cream and sits in the center of her back. Males have scattered white streaks around the edge, not a single dot. Nymphs and larvae are tiny and have no markings. For stages without the dot, look for long mouthparts that point forward and a rounded body.
Does the Lone Star tick cause Lyme disease?
No. Blacklegged (deer) ticks spread Lyme disease, and the Lone Star tick is not considered a carrier (vector). A round, growing rash after a Lone Star bite may be STARI (Southern tick-associated rash illness) instead. STARI is not Lyme. Have a doctor check any rash or symptoms.
Can a Lone Star tick bite cause a red-meat allergy?
Yes. In the US, the Lone Star tick is the tick most often linked to alpha-gal syndrome (AGS). AGS is an allergy to alpha-gal, a sugar found in meat and other products from mammals. Once a person becomes allergic, they can react hours after eating red meat such as beef, pork, or lamb. A doctor diagnoses and manages AGS.
What diseases does the Lone Star tick actually carry?
It can spread ehrlichiosis (from Ehrlichia chaffeensis and E. ewingii), Heartland virus, Bourbon virus, and tularemia. It is the tick linked to the STARI rash. It is also the main US tick linked to alpha-gal syndrome. It is not a main carrier of Rocky Mountain spotted fever, anaplasmosis, babesiosis, Powassan virus, or Lyme disease.
Does the Lone Star tick spread Rocky Mountain spotted fever?
Not as a main carrier. Most US cases of RMSF are spread by the American dog tick, Rocky Mountain wood tick, and brown dog tick. Despite the name, most cases are reported in South-Central states such as Arkansas, Oklahoma, Missouri, Tennessee, and North Carolina.
How fast should I remove a Lone Star tick?
Right away. Grasp the tick close to the skin with fine-tipped tweezers. Pull straight out with steady pressure, then clean the area. Save or photograph the tick if you can. Contact a doctor if you get a fever, rash, aches, or other symptoms in the days or weeks after a bite.
Sources
- 1.Where Ticks Live (opens in a new tab) · CDC
The Lone Star tick is widely distributed in the Northeast, South, and Midwest U.S.
- 2.Lone Star Tick Surveillance (opens in a new tab) · CDC
County-level established vs. reported records. 'Established' = 6+ ticks or multiple life stages collected in 12 months.
- 3.Ehrlichiosis (opens in a new tab) · CDC
Bacterial illness transmitted primarily by the Lone Star tick; treatable with prompt antibiotics.
- 4.Heartland Virus (opens in a new tab) · CDC
Rare virus associated with Lone Star tick bites; no specific antiviral treatment.
- 5.Bourbon Virus (opens in a new tab) · CDC
Rare tickborne virus first identified in the U.S. in 2014; supportive care only.
- 6.Tularemia (opens in a new tab) · CDC
Bacterial illness that can be spread by tick bites (including the Lone Star tick) and other routes.
Educational information only, not medical advice. If you were bitten, use the tick bite tool and contact a licensed clinician if symptoms develop. Read our sources and disclaimer.