Six tick species live in Maryland, and most of them can transmit diseases. Whether you’re hiking in the Appalachian foothills, walking your dog in a suburban park, or working in your backyard, knowing which ticks you might encounter helps you identify them quickly and understand the real risks each one carries.
Blacklegged Tick (Deer Tick)
The blacklegged tick is Maryland’s most medically significant tick and the one behind the state’s Lyme disease burden. In 2021 alone, more than 900 Lyme disease cases were reported in Maryland, making it the most commonly reported tickborne illness in the state. These ticks are small, especially in the nymph stage, when they’re roughly the size of a poppy seed and easy to miss on your skin.
Adult blacklegged ticks have a dark brown to black shield behind the head, with an orangish-red body on females. They’re noticeably smaller than American dog ticks. One important detail: a blacklegged tick must be attached for at least 36 hours before Lyme disease transmission occurs. That window is why daily tick checks matter so much. If you find and remove one the same day, your risk drops significantly. These ticks are most active from late spring through early fall, though adults can also be active on mild winter days when temperatures climb above freezing.
American Dog Tick (Wood Tick)
The American dog tick is one of the easiest ticks to identify in Maryland. It’s larger than the blacklegged tick, and its shield has distinctive whitish or silvery markings on an oval-shaped plate. Females are especially recognizable, with a large pale shield contrasting against a dark brown body. Males have more extensive mottled patterning across their backs.
This species is the primary carrier of Rocky Mountain spotted fever in Maryland and across the eastern United States. Despite the name, this disease has nothing to do with the Rockies and is well established in the mid-Atlantic. It’s a rapidly progressive illness that can become fatal within days without treatment. Symptoms start 3 to 12 days after a bite and typically begin with sudden fever and headache. A rash usually appears 2 to 4 days after the fever starts, though not everyone develops one. Nausea, body aches, and swelling around the eyes or the backs of the hands are also common. If you develop a fever after a tick bite, that’s worth urgent medical attention.
Lone Star Tick
The lone star tick is aggressive, fast-moving, and increasingly common throughout Maryland. Females are easy to spot thanks to a single white dot in the center of their back. Males have scattered white streaks or spots along the edges of their body. This tick bites humans readily and at all life stages, including as tiny larvae that sometimes attach in large numbers.
Beyond the standard tickborne infections, the lone star tick carries a unique risk: alpha-gal syndrome, a delayed allergic reaction to mammalian meat. A bite from this tick can trigger the immune system to produce antibodies against a sugar molecule called alpha-gal, which is found in beef, pork, lamb, venison, goat, and rabbit. People who develop the syndrome experience allergic reactions, sometimes including severe anaphylaxis, several hours after eating red meat or products derived from mammals. The delay between eating and reacting makes it tricky to diagnose. Maryland sits squarely in the lone star tick’s range, and alpha-gal cases have been rising across the mid-Atlantic.
Asian Longhorned Tick
The Asian longhorned tick is a relatively recent arrival to the eastern United States and has been confirmed in Maryland. It’s a small, round tick with a dark brown to blackish shield and no distinctive markings, which can make it hard to tell apart from other species without magnification. One unusual trait sets it apart: females can reproduce without mating, meaning a single tick can establish a new population. This allows infestations to build rapidly, sometimes covering livestock or wildlife in large numbers.
In its native range across East Asia, this tick transmits diseases to both humans and animals, including parasitic blood diseases that can kill cattle and reduce milk production in dairy herds. Whether it can effectively transmit North American pathogens is still being studied. For now, the biggest concern in Maryland is its potential impact on livestock and the sheer volume of ticks a single introduction can produce on a property.
When Ticks Are Most Active
Tick season in Maryland runs primarily from late spring through early fall, with peak activity during May, June, and July. This overlaps with when nymphs, the juvenile stage of blacklegged ticks, are feeding. Nymphs are the life stage responsible for most Lyme disease transmission because they’re tiny enough to go unnoticed for the 36-plus hours needed to pass the bacteria along.
Adult ticks are active in both spring and fall, and some species, particularly blacklegged ticks, remain active well into November and even during warm spells in winter. American dog ticks and lone star ticks are most active in the warmer months. The practical takeaway: tick awareness shouldn’t be limited to summer. If you’re outdoors in Maryland from March through November, tick checks should be part of your routine.
How to Identify a Tick You’ve Found
The quickest way to tell Maryland’s common ticks apart is by looking at the shield, the hard plate directly behind the head.
- Blacklegged tick: Small body, dark shield, orangish-red abdomen on females. No white markings on the shield.
- American dog tick: Larger body, oval shield with prominent whitish or silvery markings.
- Lone star tick: Medium-sized, with a single bright white dot on the female’s back. Males have faint white streaks along the edges.
- Asian longhorned tick: Small and round with a uniformly dark brown to black shield. No distinctive markings.
If you remove a tick, save it in a small sealed plastic bag. Many county health departments and extension offices in Maryland can help with identification, and knowing the species helps your doctor assess your risk for specific diseases.
Protecting Yourself Outdoors
Two repellent strategies work best when used together. DEET, applied directly to exposed skin at concentrations of 20% to 35%, makes it harder for ticks to detect you. A product with 20% to 35% DEET lasts two to four hours, while higher concentrations extend that protection up to eight hours against ticks. Concentrations above 30% aren’t more effective, just longer lasting. DEET products with 10% to 30% concentration are safe for children over two months old. Only apply DEET to skin that will actually be exposed, not under clothing.
Permethrin is the second layer. It’s an insecticide that kills ticks on contact and goes on your clothing and gear, never directly on skin. You can buy 0.5% permethrin spray at pharmacies and outdoor retailers and treat your own shoes, pants, socks, hats, and backpacks. Spray each item for 30 to 45 seconds on both sides, outdoors, and let everything dry completely before wearing it. A single treatment lasts about six weeks or through six washes.
For tick removal, use fine-tipped tweezers. Grasp the tick as close to the skin as possible and pull straight up with steady, even pressure. Don’t twist or jerk, which can break the mouthparts off in your skin. Clean the bite area with antiseptic afterward. The faster you remove an attached tick, the lower your risk of disease transmission.