The Asian Longhorned Tick in New Jersey: What to Know

How It Got Here

In 2017, a tick found on a sheep in Hunterdon County, New Jersey was identified by the Rutgers Center for Vector Biology as Haemaphysalis longicornis, the Asian longhorned tick, native to East Asia. It was the first time established populations of this species had been detected in the United States. Later research by Rutgers scientists found the tick had actually been present in New Jersey since at least 2013, quietly building populations before anyone noticed.

How it first arrived remains unknown, though researchers believe it came from northeastern Asia, possibly on imported animals or with travelers, sometime in or before 2010. From that foothold, it spread quickly. By 2023 the CDC had confirmed it in 19 states across the East and Midwest, and it continues to expand its range.

What Makes It Different From Our Native Ticks

Two traits set the Asian longhorned tick apart:

• It clones itself. The US population is parthenogenetic: females lay viable eggs without mating. One female can lay up to 2,000 eggs, according to USDA, so a single tick dropped in a new area can seed an entire infestation. Native ticks need to find a mate, which slows them down.
• It swarms hosts. Because of that reproductive strategy, infestations can be enormous. Researchers have described finding hundreds of these ticks on a person after a brief walk through infested vegetation. Heavy infestations on cattle have caused deaths from blood loss.

It is also easy to misidentify. The Asian longhorned tick looks similar to the native rabbit tick and bird tick, so Rutgers researchers published an identification key to help professionals tell them apart. If you think you have found one, save the specimen and have it identified rather than guessing.

The Real Risk to People

Here is the honest, current picture. In its native range in Asia, this tick transmits pathogens that cause serious human disease. In the United States, the CDC states that experts do not yet know whether local tick populations will make people sick. Laboratory studies have shown it is unlikely to transmit Lyme disease in any meaningful way.

That is not the same as saying it is harmless, and it is not the same as saying it is dangerous. It is an honest unknown, and it is the reason public health agencies are watching it closely. The sensible response is the same tick precautions you should already be taking in New Jersey.

Pets and Livestock: The Clearer Concern

Where the evidence is firmest is animals. The Asian longhorned tick feeds readily on dogs, cats, cattle, sheep, goats, and wildlife. In the US it has been associated with Theileria orientalis, a parasite that infects cattle red blood cells, and heavy infestations have killed cattle through blood loss. Dogs in New Jersey should stay on a veterinarian-recommended tick preventive year-round, and livestock owners should work with their veterinarian and extension service on monitoring.

How to Identify One

Asian longhorned ticks are small, reddish-brown, and lack the white markings of the lone star tick or the ornate patterning of the American dog tick. But visual identification by a homeowner is unreliable, especially for nymphs. The practical rule: any tick you cannot confidently identify should be saved in a sealed container or bag with the date, and shown to your veterinarian, your county health department, or a tick identification service. Do not try to identify a tick from a blurry phone photo alone.

What to Do If You Find One on Yourself, Your Pet, or Your Property

• Remove it the standard way: fine-tipped tweezers, grasp close to the skin, pull straight up with steady pressure, clean the area. See our tick bite guide for the full steps.
• Save the tick in a sealed bag or container with the date written on it, in case identification matters.
• Watch for symptoms in the following weeks and call your doctor if anything develops.
• Check pets thoroughly, especially after time in tall grass or brush, and keep them on preventive treatment.
• Reduce tick habitat in your yard: clear leaf litter, trim vegetation at lawn edges, and consider professional treatment of the areas where ticks quest.

Laurie’s field note: What keeps me up at night about this tick is not the disease question, it is the math. One female, no mate needed, thousands of eggs. When I treat a property bordering open fields or farmland, I am thinking about exactly this species. Early treatment of the habitat beats trying to deal with an established population later.

FAQ: Asian Longhorned Tick

The Takeaway: Respect It, Do Not Fear It

The Asian longhorned tick is a genuine newcomer worth taking seriously, especially for pet owners and anyone bordering fields or farmland. But the playbook has not changed: check yourself and your pets, remove ticks promptly, and keep your yard’s tick habitat under control. The species is new. The defense is the same one that works against every tick in New Jersey.

Trusted sources: Rutgers NJAES: Where did the Asian longhorned ticks in the US come from? • CDC: About Ticks