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Species profile

Asian longhorned tick

Haemaphysalis longicornis

An invasive hard tick established in parts of the eastern United States and a major livestock concern. U.S. populations reproduce parthenogenetically.

Adult female Haemaphysalis longicornis Asian longhorned tick climbing a blade of grass
Adult female

Image credit:James Gathany / CDC Licence termsSource

Also known as: Bush tick, Cattle tick, Scrub tick

Image gallery

Adult female Haemaphysalis longicornis Asian longhorned tick climbing a blade of grass
Adult female

Image credit:James Gathany / CDC Licence termsSource

Quick facts

Family: Ixodidae. Genus: Haemaphysalis. Hard tick.

Identification

Unfed stages are small and reddish-tan to dark reddish-brown. Adult females can become grey-green after feeding. Definitive identification requires expert examination.

Photographs and location alone may be insufficient for confirmation; use expert morphological examination when reliable species identification is required.

Photographs alone cannot always confirm this species. Geographic location and host are supporting context, not conclusive identification.

Sex and appearance differences

APHIS reports that males are rare in established U.S. parthenogenetic populations. Adult females can reproduce without mating.

Life cycle

Three-host hard-tick life cycle with egg, larva, nymph and adult stages.

Life stages

  • Egg
  • Larva
  • Nymph
  • Adult

Seasonal activity

APHIS reports general activity from March to November, varying by year and locality.

Hosts

  • Humans (Homo sapiens)
  • Cattle (Bos taurus)
  • Sheep
  • Goats
  • Horses
  • Dogs (Canis lupus familiaris)
  • Deer
  • Wildlife

Habitats

  • Pasture
  • Grassland and shrubland
  • Woodland edges and trails

Distribution

Introduced and established in multiple eastern U.S. states. Official county records and establishment status should be read from current USDA surveillance.

Presence, established populations, habitat suitability and disease risk are distinct evidence categories.

Countries and regions

  • United States — introduced_established

    Introduced and established in multiple eastern U.S. states. Official county records and establishment status should be read from current USDA surveillance.

  • Oceania — present

    New Zealand MPI identifies Haemaphysalis longicornis as the established New Zealand cattle tick.

  • Asia — present

    Peer-reviewed pooled distribution evidence identifies Haemaphysalis longicornis as native to and predominantly distributed in eastern Asia.

  • Delaware — present

    Delaware DNREC lists the Asian longhorned tick among the five species commonly found in Delaware.

  • Indiana — present

    Indiana Department of Health identifies the Asian longhorned tick among tick species of public-health relevance in Indiana.

  • New Jersey — present

    New Jersey DEP records the Asian longhorned tick in multiple New Jersey counties.

  • Ohio — present

    The Ohio state-commissioned study reports the first detection of the Asian longhorned tick in Ohio.

  • Pennsylvania — present

    Pennsylvania DEP frequently collects Asian longhorned ticks during statewide surveillance.

  • South Carolina — present

    South Carolina DPH lists the Asian longhorned tick among six species often encountered in South Carolina.

  • Tennessee — present

    Tennessee Department of Health lists the Asian longhorned tick among six key species and notes it was recently found in eastern Tennessee.

Medical and veterinary relevance

Bites humans but CDC describes it as less attracted to people than several common native U.S. ticks. Potential and laboratory competence must be separated from confirmed field transmission.

High veterinary importance because heavy infestations can affect livestock and it transmits Theileria orientalis Ikeda.

Pathogens and diseases

  • Theileria orientalis Ikeda infection — veterinary_disease
  • Heartland virus disease — disease

    CDC identifies the lone star tick as the vector of Heartland virus.

Detection of a pathogen in a tick does not by itself establish that the species is a confirmed vector.

Vector and pathogen evidence

Confirmed vector of Theileria orientalis Ikeda in cattle. Laboratory Heartland virus transmission does not establish its field role in U.S. human disease. U.S. evidence indicates incompetence for Borrelia burgdorferi and Anaplasma phagocytophilum.

Medical importance

Veterinary importance

Prevention and removal guidance

Use current public-health and veterinary guidance, avoid known tick habitats where practical, use suitable repellents or protective clothing, and check people and animals after exposure.

Remove attached ticks promptly using fine-tipped tweezers or an appropriate tick-removal tool. Seek medical or veterinary advice when symptoms or concerns arise.

Important identification and health information

Educational information and limitations

Photographs and visible features may be insufficient for definitive identification.

This educational information is not a diagnosis or a substitute for medical or veterinary advice.

This educational information does not replace examination or advice from a qualified veterinary professional.

Presence, established populations, habitat suitability and disease risk are distinct evidence categories.

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