What you need to know about Asian longhorned ticks – A new tick in the United States

What do Asian longhorned ticks look like?

Nymph and adult female longhorned ticks

Nymph and adult female, top view.

Undersides of nymph and adult female longhorned ticks

Nymph and adult female, underside.

What we know about Asian longhorned ticks in the U.S.

Can this Tick's Bite Make Me Sick?

Many species of ticks live in the United States. Each tick species can carry and spread different types of germs.

When a scientist discovers a new germ in a tick, studies are needed to determine if the tick can carry and spread germs to a person or animal. Scientists need to determine:

  • Can the germ survive and multiply in the tick?
  • Can (enough) germs be passed through a tick bite to cause an infection?
  • Not normally found in the Western Hemisphere, these ticks were reported for the first time in the United States in 2017.
  • Asian longhorned ticks have been found on pets, livestock, wildlife, and people.
  • The female ticks can lay eggs and reproduce without mating.
  • Thousands of ticks may be found at a time in grass or shrubs or on an animal.
  • Researchers are looking for these ticks to find out where they live and if they prefer wooded or more open areas.
  • As of April 13, 2023, longhorned ticks have been found in Arkansas, Connecticut, Delaware, Georgia, Indiana, Kentucky, Maryland, Massachusetts, Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, and West Virginia.
  • Compared with well-known native ticks (such as the blacklegged tick, lone star tick and American dog tick), the Asian longhorned tick appears to be less attracted to human skin.
  • In other countries, germs spread via bites from these ticks can make people and animals seriously ill.
    • With ongoing testing of ticks collected in the United States, it is likely that some ticks will be found to contain germs that can be harmful to people. However, we do not yet know if and how often these ticks are able to pass these germs along to people and make them ill. (See sidebar.)
    • One recent experimental study found that this tick is not likely to contribute to the spread of Lyme disease bacteria in the United States.
    • Another laboratory study found that this tick has the ability to carry and spread the bacteria that causes Rocky Mountain spotted fever (Rickettsia rickettsii). The germs that cause Rocky Mountain spotted fever have not yet been found in these ticks in nature.
    • Research is ongoing.
  • You can protect yourself from tick bites.  CDC-recommended personal protective measures such as the use of EPA-approved insect repellents and 0.5% permethrin-treated clothing are effective against Asian longhorned ticks.

What you should do if you think you have found an Asian longhorned tick

  • Remove ticks from people and animals as quickly as possible.
  • Save the ticks in rubbing alcohol in a jar or a ziplock bag, then:
    • Contact your health department about steps you can take to prevent tick bites and tickborne diseases.
    • Contact a veterinarian for information about how to protect pets from ticks and tick bites.
    • Contact your state agriculture department or local agricultural extension office about ticks on livestock or for tick identification.


Asian longhorned tick videos from the Northeast Regional Center for Excellence in Vector-Borne Diseases

Additional Resources

USDA National Haemaphysalis longicornis (Asian longhorned tick) Situation Report [PDF – 8 pages] (updated monthly)

Beard CB, Occi J, Bonilla DL, et al. Multistate infestation with the exotic disease-vector tick Haemaphysalis longicornis – United States, August 2017-September 2018. MMWR Morb Mortal Wkly Rep. 2018 Nov 30;67(47):1310-1313.

Breuner NE, Ford SL, Hojgaard A, et al. Failure of the Asian longhorned tick, Haemaphysalis longicornis, to serve as an experimental vector of the Lyme disease spirochete, Borrelia burgdorferi sensu stricto. Ticks Tick Borne Dis. 2020 Jan;11(1):101311.

Foster E, Fleshman AC, Ford SL, et al. Preliminary evaluation of human personal protective measures against the nymphal stage of the Asian longhorned tick (Acari: Ixodidae). J Med Entomol. 2020 Feb 19. Ahead of press.

Pritt BS. Haemaphysalis longicornis is in the United States and biting humans: Where do we go from here? Clin Infect Dis. 2020 Jan 2;70(2):317-318.

Rainey T, Occi JL, Robbins RG, Egizi A. Discovery of Haemaphysalis longicornis (Ixodida: Ixodidae) parasitizing a sheep in New Jersey, United States. J Med Entomol. 2018 May 4;55(3):757-759.

Stanley HM, Ford SL, Snellgrove AN, et al. The ability of the invasive Asian longhorned tick, Haemaphysalis longicornis (Acari: Ixodidae) to acquire and transmit Rickettsia rickettsii (Rickettsiales: Rickettsiaceae), the agent of Rocky Mountain spotted fever, under laboratory conditions. J Med Entomol. 2020 Apr 27. Ahead of press.

Tufts DM, VanAcker MC, Fernandez MP, et al. Distribution, host-seeking phenology, and host and habitat associations of Haemaphysalis longicornis ticks, Staten Island, New York, USA. Emerg Infect Dis. 2019 Apr;25(4):792-796.

Wormser GP, McKenna D, Piedmonte N, et al. First recognized human Bite in the United States by the Asian longhorned tick, Haemaphysalis longicornis. Clin Infect Dis. 2020 Jan 2;70(2):314-316.