State Agriculture Department and Cornell Integrated Pest Manageme...

The New York State Department of Agriculture and Markets and Cornell Integrated Pest Management (Cornell IPM), a program of Cornell University’s College of Agriculture and Life Sciences, today urged New York livestock producers to take preventative measures against the Asian longhorned tick (LHT).  LHT is an invasive pest that, since it was first identified in the United States in New Jersey in 2017, has steadily expanded northward and is now becoming a serious concern for the health of livestock throughout the Hudson Valley.

State Agriculture Commissioner Richard A. Ball said, “Asian longhorned tick is increasingly becoming a concern for our livestock producers, particularly in the Hudson Valley area, where our partners at Cornell IPM have seen a significant uptick in activity. The good news here is that by being vigilant and taking proactive measures, our producers can keep their animals healthy and safe.  I urge all of our cattle, sheep and goat producers to take a look at the ways they can reduce the threat of the longhorned tick and follow their veterinarian’s guidance.”

Cornell IPM Associate Director and Livestock Coordinator Ken Wise said, "We are actively and vigilantly monitoring the spread of the Asian longhorned tick across New York State to better understand its distribution, habitat selection and potential impacts on livestock and animal health. Through ongoing surveillance efforts, we are tracking population levels and providing science-based management recommendations when tick populations reach levels that may pose a risk to animal health and productivity."

LHT is especially concerning because it can reach extremely high populations on animals, which can cause significant blood loss, leading to anemia, reduced performance, and in extreme cases, death of livestock animals.  LHT is also capable of transmitting a parasite that causes theileriosis, which can lead to reduced milk production, weakness and weight loss, pale, white, or jaundice mucous membranes fever, and even death. Theileriosis has now been detected in cattle in the Hudson Valley, and at least one livestock death associated with the disease has been confirmed in the region.

The disease may also infect sheep and goats, which do not get clinically ill and serve as “asymptomatic carriers”.  Swine do not get theileriosis.

While LHT is the primary vector for the spread of theileriosis in affected areas, biting flies and sharing needles between animals can also contribute to animal infection.  Posing an additional challenge, unlike blacklegged ticks and American dog ticks, which are usually concentrated along wooded edges and areas with heavy cover, LHT can thrive in open grassy pastures. 

Preventative Measures

There are a number of preventative and proactive measures that livestock producers can take to protect their animals.  These include ensuring introduced animals are tick-free; screening new cattle for theileriosis before introducing them to the herd; monitoring herds; making informed treatment decisions; and using integrated pasture management strategies will be critical for reducing impacts on livestock while preserving beneficial pasture ecosystems.

• Testing and Herd Monitoring
  Producers should work with veterinarians to determine herd infection status. Testing may be especially important before purchasing or introducing new animals, especially from regions endemic with theileriosis, such as the southern and southeastern US, and in areas where Asian longhorned ticks are established. 
• Pasture Management
  If a pasture has high levels of LHT, resting the pasture for one year can help reduce populations. Maintaining pasture edges by mowing and removing shrubs and bushes, both inside and outside fence lines, can also help minimize tick habitat. High-traffic areas, such as around gates, water sources, feeding areas and handling facilities, should be kept mowed and cleared of excess vegetation to reduce cover and limit pest buildup. Broadcast spraying pastures is generally not effective for controlling LHT and can otherwise negatively impact beneficial insects and pasture ecology.
• Spraying Animals 
  Direct application of approved acaricide products to livestock is one of the most effective methods for controlling Asian longhorned ticks.
• Ear Tags
  Ear tags provide control primarily in and around the ears and head region. They do not adequately protect the entire animal from Asian longhorned ticks. If ear tags are used: rotate active ingredients between years; avoid switching active ingredients during the same season; and follow all label directions carefully. 

Tick Expansion in New York and Identification

Since its discovery, the LHT has gradually spread in the Hudson Valley. During the 2026 season, established tick populations have been confirmed as far north as the Kinderhook area of Columbia County. High infestation rates have been observed in some herds. 

Asian longhorned ticks are very small, making early detection difficult. Adult ticks are typically only 2–3 mm long and 1–2 mm wide, appearing at first glance like tiny brown specks of dust. Nymphs and larvae are even smaller.

For additional information and resources on the LHT, please visit Cornell IPM’s website at: https://cals.cornell.edu/integrated-pest-management/outreach-education/whats-bugging-you/asian-longhorned-tick 

Products for use on livestock: https://cornell.app.box.com/v/tick-mgnt-products-livestock