11 Dangerous Ticks In America That Transmit Diseases

America is home to numerous species of disease-transmitting ticks. They are a formidable threat to anyone’s health.

Dangerous ticks live wherever their hosts reside. Like all nasty parasites, they simply can’t live without a host to quench their bloodlust. However, during their feast, certain species transmit dangerous life-altering diseases such as Lyme disease, Ehrlichiosis and Tularemia.

In this article, we will focus upon the identification, location and diseases these dangerous menaces can potentially transmit to humans. 

LONE STAR TICK
  (Amblyomma americanum)

Image Courtesy of CDC

The Lone Star tick is extremely aggressive and notorious for biting humans. A female is immediately identifiable due to the white dot “hence lone star” located on her back. The rest of her body is a reddish-brown that easily blends in a natural environment. The smaller male is of the same color, but has a pale lacy white marking on the rear edge of the shield that covers his back. Newly hatched larvae and developing nymphs are a reddish-brown.

Adults are primarily active during the spring and early summer. However, larvae and nymphs stay around from spring until late fall. Nymphs pose a significant threat because they are less than 2 millimeters in size (which allows them to go undetected), bite and can transmit tick-borne infections to humans.  

Image Courtesy of CDC

The Lone Star tick is found throughout the southeastern, midwestern and eastern United States. However, climate change, shifts in animal migration patterns, deforestation, urbanization and globalization has permitted this deadly vector of diseases to expand into the northern hemisphere. 

The Lone Star tick transmits bacteria and viruses that causes several types of illnesses such as: 

• Bourbon Virus. 
• Ehrlichiosis. 
• Heartland Virus. 
• Tularemia.
• Stari. (Southern Tick Associated Rash Illness). 
• Alpha Gal Syndrome. (while this isn’t technically a disease, the Lone Star tick is notorious for causing red meat allergies in humans). 

ROCKY MOUNTAIN WOOD TICK
 (Dermacentor andersoni)

Image Courtesy of CDC

The Rocky Mountain Wood tick takes up residency in the Rocky Mountain states, west to the eastern slope of the Cascade Mountains, and south to Arizona and New Mexico. In the Pacific states, it is usually found in higher elevations from 4,000 to 10,500 feet. This sickening bloodsucker has even found its way to Alaska. 

Image Courtesy of CDC

The female has a silvery grey marking on her shield on the front third of her back; the rest is reddish-brown. Her male companion has silvery grey markings on the shield on all of his back. Larvae and nymphs are a dark reddish-brown.

During the winter, adults bury themselves in the soil and become extremely active in early summer. Larvae are also active during summer months. However, nymphs are active from spring to summer months. Nymphs are a constant threat outdoors because they can latch on and remain unseen for a prolonged period of time. Let’s not forget that they can also transmit tick-borne infections to humans. 

A bite from an infected Rocky Mountain Wood tick can transmit bacteria and a virus that causes the following illnesses:

• Colorado Tick Fever. 
• Powassan encephalitis.
• Rocky Mountain Spotted Fever. 
• Tularemia.
• Tick paralysis. (caused by a neurotoxin in the tick’s saliva). 

BLACKLEGGED TICK/DEER TICK
 (Ixodes Scapularis)

Image Courtesy of CDC

This disgusting formidable bloodsucker can be found all across the eastern two-thirds of the United States and into Canada. In the northeast, this tick is commonly called the deer tick because it was first discovered on deer. In the Midwest, it is often called the bear tick, hence its name because it was first discovered on bears. Either way it still poses a considerable threat to anyone enjoying the outdoors. 

Image Courtesy of CDC

The female is a very dark-reddish brown and has no markings on her back, although the shield on the front third of her body is visible. The male on the other hand is black. Both male and females have black legs “hence the name black-legged tick” unlike other species that generally have brown or brownish red legs. Larvae are very dark colored and the dreaded nymphs (that are the size of a poppy seed) are a dark reddish-brown. Be aware that infected nymphs are more than capable of transmitting disease-causing organisms.

Larvae are abundant from late July-August, nymphs April-July and adults mid-October to early December. Here is where it gets interesting. Unlike most ticks that hole up during the winter, this dangerous species will seek out a blood meal whenever the temperature is above freezing and the ground is not blanketed with snow. Just because it's winter, you still have to be aware of their presence.

The teardrop-shaped Blacklegged tick transmits pathogens that cause life-altering diseases such as: 

• Lyme disease.
• Babesiosis.
• Anaplasmosis previously known as Human Granulocytic Ehrlichiosis.
• Powassan encephalitis.
• Bartonellosis / Cat Scratch disease.
• Tick-borne encephalitis. 
• Borrelia Miyamotoi. 

WESTERN BLACKLEGGED TICK
(Ixodes Pacificus)

Image Courtesy of CDC

Now let's focus on another monstrosity: the Western Blacklegged tick. These ticks are found along the Pacific Coast as well as in parts of Arizona, Idaho, Nevada and Utah. They look virtually identical to the above-mentioned Blacklegged tick, and like them, adult females can lay between 2,000 to 3,000 eggs at one time. 

Image Courtesy of CDC

An adult female has a solid black shield covering a portion of its back and is a dark reddish-brown color, becoming grey, taupe then lighter after feeding. An adult male can have various colors from dark reddish-brown to black. Larvae are black but due to their transparency may take on a flesh-color when attached and feeding. A nymph's color can vary from brown to black.

Adults are active from November through May. Larvae and nymphs begin feeding from late winter through the summer.

Unlike other tick bites that go unnoticed, a bite from the Western Blacklegged tick isn’t as subtle. When you’re bitten, you’ll definitely know it. The bite generally hurts and it’s slow to heal.

Just like their east coast brethren (i.e. Blacklegged tick), it shouldn’t surprise you that adults and nymphs are capable of transmitting the following tick-borne illnesses:

• Anaplasmosis (previously known as Human Granulocytic Ehrlichiosis).
• Babesiosis.
• Bartonellosis / Cat Scratch disease.
• Borrelia Miyamotoi.
• Lyme disease.
• Powassan encephalitis.

GULF COAST TICK
(Amblyomma Maculatum)

Image Courtesy of CDC

This dangerous disease-transmitting tick can be found along the Atlantic Coast and specifically the Gulf of Mexico “hence the name Gulf Coast tick”. However, don’t let its name fool you. It has also been located in Arkansas, Oklahoma, South Western Tennessee and South Eastern Missouri. There is a serious public concern that this species may be expanding its range northward. 

Image Courtesy of CDC

The adult female is easily recognizable due to the dark brown scutum (back shell) with a silvery white ornamentation near her head that includes three lateral uninterrupted lines. Adult males have a dark brown scutum with interconnected silvery white lines. Adults can grow over 6mm in length. Nymphs on the other hand have a shiny appearance and can range in color from dark bluish gray to a dull white.

In the Southeast, this tick can be active year-round due to the warmer climate. Adults are typically active from spring to late fall, while nymphs are more active in winter months. In northern regions of the United States, the activity of this species may vary. 

The Gulf Coast tick is notorious for transmitting the following diseases:

• Rickettsia parkeri rickettsiosis, a form of spotted fever. 

AMERICAN DOG TICK
(Dermacentor variabilis)

Image Courtesy of CDC

In many places, this disease-transmitting tick is also known as the wood tick. It is widely distributed throughout the eastern half of the United States and along the West Coast. This dangerous species is also common in Canada and can be found from Saskatchewan east to the Atlantic Provinces. 

Image Courtesy of CDC

An adult female has silvery gray markings on the shield on the front third of her back and the rest of her body is a reddish-brown. Female American Dog ticks are very identical to female Rocky Mountain Wood tick and Pacific Coast tick. Adult males on the other hand have silvery grey markings all over their back. Larvae are dull yellow and nymphs are reddish-brown.

Adult American Dog ticks seek refuge in the soil during the winter. However, when they emerge from their slumber, they are active from spring to summer. Larvae and nymphs are also active from spring to summer. American Dog ticks are widely known to be the largest tick species. Depending on whether or not they have fed on a host, they can range in size from 5 to 15 millimeters. 

This species is another parasite you need to pay attention to because it is known to transmit the following diseases: 

• Rocky Mountain Spotted Fever.
• Ehrlichiosis.
• Tularemia. 
• Tick paralysis (caused by a neurotoxin in the tick’s saliva). 

PACIFIC COAST TICK
(Dermacentor Occidentalis)

This dangerous parasite is found predominantly in shrub-lands and along trails. They have quietly settled all the way from Oregon to northern Baja, California and crossed the border into Mexico. These little devils are commonly found throughout most of California and are sometimes confused with other less common ticks like the above-mentioned Rocky Mountain Wood tick and American Dog tick. 

The adult female has a pronounced silvery grey pattern on the shield of her back and the rest of her body is a reddish brown. Her male companion has silvery grey markings on all of his back. Unlike their parents, larvae and nymphs have less colorful features and are a dark brown color.

In the warmer regions of its southern range, these ticks are active throughout the year with a significant increase of occurrence during the spring. Remember, warmer climates help these unsightly parasites thrive and seek out blood meals all year round. In northern regions, larvae and nymphs hunt their meals down from spring to fall. Their adult parents are most active during the spring. 

Make no mistake this species is a human biter and responsible for transmitting the following diseases: 

• Pacific Coast Tick Fever (a form of spotted fever). 
• Tularemia.
• Colorado Tick Fever.
• Tick Paralysis (caused by a neurotoxin in the tick’s saliva). 

BROWN DOG TICK
(Rhipicephalus sanguineus)

Image Courtesy of CDC

This disgusting species is found throughout the world. We simply just can’t avoid this vicious bloodsucker. Although dogs are its primary host for each of its life stages, this tick will not hesitate to deliver a nasty disease-transmitting bite to humans. They are often mistaken for BlackLegged ticks (i.e. deer ticks). 

Image Courtesy of CDC

Time to raise the alarm. Frequently, when people report a tick infestation on their dogs or in their home, they immediately believe they have several species of ticks crawling about. However, they are actually observing multiple life stages of nasty Brown Dog ticks looking for a blood meal. Fed females will lay thousands of eggs in cracks along baseboards, window frames, door frames and even your rug.

Oh it gets better! As fed adults, larvae and nymphs drop off dogs, they start creeping about looking for a new host to attach on. Just thinking about it would make anyone’s skin crawl.

Mature females are a dark brown, with the front third of her back being darker than the rest of her body. When she feeds, her color changes to a brownish grey. Nasty right! The adult male is a uniform dark brown, and offspring (i.e. larvae and nymphs) are dark brown. 

They are a serious threat, because they are known to transmit tick-borne illnesses to both dogs and humans such as: 

Canine:

• Ehrlichiosis.
• Babesiosis. 

Humans:

• Rocky Mountain Spotted Fever. 

GROUNDHOG TICK
 (Ixodes Cookei)

Image Courtesy of CDC

We are not out of the woods yet. The Groundhog tick also known as Woodchuck ticks are another menace to be aware of. They are very similar in appearance to Blacklegged Deer ticks. Despite their similarities, Groundhog ticks have not been associated with Lyme disease transmission and do not typically deliver a nasty bite to humans. 

These disease-transmitting terrors are found anywhere east of the Rocky Mountains and have made their presence known in New England, the Northern Midwest, around the Great Lakes and Southern Canada. This is one of the most commonly encountered species in Maine.

Adult females are about the size of a sesame seed and have a tan to reddish-tan color with a darker dorsal shield or scutum on the back, behind their head. Males are smaller and similar in color. Their larvae and nymphs are a lighter tan color and definitely smaller than a sesame seed. 

The Groundhog tick is another threat to be vigilant of because it transmits the following disease:

• Powassan Virus ( can become life-threatening and people who survive experience long term complications). 

RELAPSING FEVER TICKS
 (Ornithodoros Hermsi, O. parkeri, O talajae and O turicata)

Image Courtesy of CDC

These four types of leathery soft ticks look alike and have similar life cycles. Adults are gray to pale blue and their oval-shaped soft bodies have a rough texture. Larvae and nymphs are grey.

Ornithodoros Hermsi is primarily found in Western North American in elevations ranging from less than 3,000 feet to over 8,000 feet in mountainous areas of California, Colorado, Utah, Idaho, Montana and Washington.

O. parkeri is primarily found in lower elevation and abundant throughout the Southwest.

O. talajae are geographically located in Arizona, California, Florida, Kansas, Nevada and extending its range along the Gulf Coast to Texas.

O. turicata is also found in lower elevations and widely distributed from California to Texas. This soft tick is also abundant in Florida.

Soft ticks do not search for their prey in tall grass or shrubs. Instead, they live in animal burrows. They feed as needed on the animal as it sleeps. For example, Ornithodoros parkeri soft ticks are commonly found in caves and burrows of ground squirrels and prairie dogs. As the animal is quietly tucked away in its burrow, these soft ticks creep up and start feeding.

We come into contact with these raisin-shaped parasites when we sleep in rodent-infested cabins. As we are enjoying a deep sleep, a soft shell tick quietly emerges at night and feeds on an unsuspecting guest. Bites are painless and you’ll never know what hit you. Once full, it detaches and quietly returns to the nesting material in the host’s burrow. Be extremely cautious if you decide to spend the night in an old cabin.

Soft ticks can live up to 10-20 years, which means once a cabin or homestead is infested, it will remain infested unless remedial methods are taken to locate and remove rodent nests.

As the name implies, all four of the above-mentioned soft ticks carry Tick-Borne Relapsing Fever. Most cases of (TBRF) occur in the summer months when more people are sleeping in rodent-infested cabins. However, TBRF can also occur in winter months when a fire is started to warm a cabin. The heat generated activates the ticks resting in the walls and woodwork. 

Cave explorers are also at risk of acquiring Tick-Borne Relapsing Fever. Ornithodoros Parkeri is one one the above-mentioned disease-transmitting soft ticks that is commonly found in caves.

ASIAN LONGHORNED TICK
(Haemaphysalis longicornis)

Image Courtesy of CDC

This invasive species hitched a ride somewhere and found its way into the United States. This new menace is native to eastern China, Japan, the Russian Far East and Korea. It’s speculated that it has been in the United States since 2010. However, in 2017, it was discovered on a sheep farm in New Jersey.

The CDC states that, “as of October 5, 2020, this species has been found in Arkansas, Connecticut, Delaware, Kentucky, Maryland, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia and West Virginia”. 

As with any other tick species, this menace can easily find its way into other states. Health officials are worried because this new aggressive biter is here to stay. As if we didn’t have enough to worry about.

The U.S. Centers for Diseases Control and the USDA Department of Agriculture are closely monitoring this exotic species because it can easily spread into other states and thrive. Unlike other ticks, a female Asian Longhorn can reproduce without mating and lay up to 2,000 eggs at a time. As a direct result, thousands can be found in localized areas on cattle, pets or people.

This tick is extremely worrisome because it feeds on humans, livestock, pets and wildlife. Most frightening is its ability to introduce new pathogens into the Western Hemisphere. 

This new invasive species is capable of transmitting the following diseases:

• Japanese Spotted Fever (Yet to be found in the United States but there is a risk of future introduction). 
• Human Hemorrhagic Fever (usually occurs in tropical climates).
• Heartland Virus.
• Powassan Virus (can become life-threatening and people who survive experience long term complications). 
• Lyme disease.
• Rocky Mountain Spotted Fever. 

FINAL NOTE.

We aim to raise awareness of the above-mentioned disease-transmitting ticks. The threats they pose should never go unrecognized because a single bite can have devastating consequences.

Be advised that this is not an exhaustive list, as other dangerous species (both invasive and domestic) may be lurking outdoors.

To best avoid becoming their host, it’s important to take preventative measures to keep you and your loved ones safe. Also, it's extremely important to perform a "tick check" when returning home from the outdoors.