New Jersey is home to three major disease-carrying tick species and ranks as the fourth highest state in the country for reported Lyme disease cases. Whether you’re hiking the Pine Barrens, gardening in your backyard, or walking your dog through a suburban park, ticks are a real and growing concern across the state. Here’s what you need to know about the species you’ll encounter, the diseases they carry, where the risk is highest, and how to protect yourself.
Tick Species Found in New Jersey
Three native tick species are responsible for transmitting disease in New Jersey: the blacklegged tick (commonly called the deer tick), the lone star tick, and the American dog tick. Each one looks different, favors different hosts, and carries different pathogens.
The blacklegged tick is the smallest of the three and the most medically significant. Adults are roughly the size of a sesame seed, with dark brown or black legs and an orange-red body. Nymphs, the immature stage most likely to bite people undetected, are about the size of a poppy seed. This is the tick behind Lyme disease, anaplasmosis, babesiosis, and Powassan virus in New Jersey.
The lone star tick is easy to identify: adult females have a single white dot on the center of their back. These ticks are aggressive biters and will actively pursue a host rather than simply waiting on a blade of grass. They transmit ehrlichiosis and are strongly linked to alpha-gal syndrome, a potentially life-threatening allergic reaction to red meat.
The American dog tick is the largest of the three, with distinctive white or gray markings on its back. It’s most active in spring and summer and is the primary carrier of Rocky Mountain spotted fever in the state.
A fourth species, the Asian longhorned tick, is an invasive newcomer. First detected in Hunterdon County in November 2017, it was the first confirmed population of this tick in the Western Hemisphere outside of a port inspection site. It has since spread across much of the eastern United States. What makes this tick unusual is that females can reproduce without mating, essentially cloning themselves, which allows populations to explode quickly. A single animal can become covered in hundreds or thousands of ticks. So far, this species has not been shown to transmit Lyme disease or anaplasmosis to humans, but it does carry a cattle pathogen and is being closely monitored.
Diseases Ticks Carry in New Jersey
The New Jersey Department of Health tracks nine tick-borne diseases in the state: Lyme disease, anaplasmosis, babesiosis, ehrlichiosis, Rocky Mountain spotted fever (and related spotted fever infections), Powassan virus, tularemia, Borrelia miyamotoi infection, and alpha-gal syndrome.
Lyme disease dominates the list. New Jersey is classified as a high-incidence state, with an average of about 69 cases per 100,000 residents per year since the case definition was updated in 2022. Early symptoms typically include a spreading rash (often but not always in the classic bull’s-eye pattern), fever, fatigue, and joint pain. Caught early, it responds well to antibiotics. Left untreated, it can progress to joint inflammation, nerve problems, and heart issues.
Babesiosis is worth knowing about because it attacks red blood cells and can be severe in older adults or anyone with a weakened immune system. Many people with babesiosis never develop symptoms, but those who do experience flu-like illness that can become dangerous. Anaplasmosis causes similar flu-like symptoms and is also transmitted by the blacklegged tick.
Alpha-gal syndrome is a newer concern. Triggered by lone star tick bites, it causes an allergic reaction to a sugar molecule found in most mammalian meat, including beef, pork, and lamb. Reactions typically occur three to six hours after eating and can range from hives to anaphylaxis. New Jersey began statewide surveillance for alpha-gal syndrome in January 2022 to better track where cases are rising.
Powassan virus is rare but serious. Unlike Lyme disease, which typically requires a tick to be attached for 36 to 48 hours, Powassan virus can be transmitted in as little as 15 minutes. There is no specific treatment, and severe cases can cause brain inflammation.
When Tick Season Peaks
Tick season in New Jersey runs from April through September, with May and June being the most dangerous months. May is officially designated Tick Awareness Month in the state. This peak aligns with when blacklegged tick nymphs are most active. Because nymphs are tiny and their bites are painless, most people who contract Lyme disease are bitten by nymphs they never noticed.
Adult blacklegged ticks have a second active window in fall and early winter, remaining active on days when temperatures stay above freezing. American dog ticks and lone star ticks are primarily warm-weather species, with activity dropping off sharply by late September. The bottom line: peak risk is late spring and early summer, but you shouldn’t let your guard down completely until the ground is consistently frozen.
Highest-Risk Counties
Tick-borne disease is not evenly distributed across New Jersey. The northwestern counties carry dramatically higher Lyme disease rates than the rest of the state. Based on 2024 data from the New Jersey Department of Health, Hunterdon County leads the state with an incidence rate of 457 per 100,000 residents. Warren County follows at 373, and Sussex County at 294. Morris and Somerset counties round out the top five.
These counties share common features: large tracts of forest, abundant white-tailed deer populations, and suburban neighborhoods that border wooded areas. That edge habitat, where lawn meets forest, is prime tick territory. But even densely populated counties like Bergen, Middlesex, and Passaic report consistent Lyme disease cases. Urban and suburban residents who visit parks, walk trails, or have yards bordering green space are still at risk.
Southern New Jersey counties like Cumberland, Salem, and Cape May have lower rates, though lone star ticks are well-established in parts of the southern Pine Barrens and coastal areas. If you spend time outdoors anywhere in the state, tick precautions apply.
How to Protect Yourself
Prevention comes down to two strategies: keeping ticks off your body and finding them quickly if they get on.
For repellents, DEET at concentrations between 20% and 35% is effective for most outdoor activities. Picaridin at 20% concentration works comparably and has less odor. Oil of lemon eucalyptus is an EPA-registered plant-based option. These go on exposed skin. For clothing, permethrin is the gold standard. It kills ticks on contact and remains effective through several washes. You can buy pre-treated clothing or spray your own gear. Permethrin should never go directly on skin.
After spending time outdoors, do a full-body tick check. Pay attention to hidden spots: behind the ears, along the hairline, in the armpits, behind the knees, around the waist, and in the groin area. Shower within two hours of coming inside. Tossing clothes in a hot dryer for 10 minutes kills any ticks hitchhiking on fabric, even if the clothes are dry.
If you find an attached tick, use fine-tipped tweezers to grasp it as close to the skin as possible and pull straight up with steady, even pressure. Don’t twist, squeeze the body, or use nail polish, petroleum jelly, or a hot match. Clean the bite area with rubbing alcohol or soap and water. Save the tick if you can.
Free Tick Testing Through Rutgers
New Jersey residents have access to a valuable free resource. The Rutgers Center for Vector Biology runs a citizen science project called “NJ Ticks 4 Science” that accepts ticks found anywhere in the state and tests them for disease-causing pathogens at no cost. The program helps build a real-time map of tick distribution and pathogen prevalence across New Jersey’s counties, and every submission contributes to the state’s understanding of where risks are shifting. If you pull a tick off yourself, a family member, or a pet, sending it to Rutgers can tell you whether that specific tick was carrying anything concerning, which can help guide conversations with your doctor about whether preventive treatment makes sense.