The invasive Asian longhorned tick has been spotted in a new part of the U.S. Click to Know!

An invasive tick species that has been reported in more than 20 states has been found in Maine for the first time, officials said.

The Asian longhorned tick was first discovered in New Jersey eight years ago. Experts say the Maine discovery marks the farthest the tick has been seen in the Northeastern United States.

"This discovery highlights the importance of continued tick surveillance in Maine," Griffin Diehl, director of the University of Maine Extension Tick Lab, a tick surveillance program, said in a news release last month. "While this appears to be an isolated incident, we are closely monitoring the situation and coordinating with state and federal partners." Diehl noted that early detection "is crucial to understanding and mitigating the potential risks associated with this species."

The tick in Maine was submitted through the University of Maine's tick lab and confirmed by the university and Maine's agriculture and forestry department, Maine officials said. The tick that was found was not fully grown and couldn't reproduce, and no additional ticks of the same species were found in the area during subsequent observation.

What is the Asian longhorned tick?

The Department of Agriculture's Animal and Plant Health Inspection Service describes Asian longhorned ticks as "invasive pests that pose a serious threat to livestock in the United States."

"They can form large infestations on one animal and spread diseases that impact both animals and people," it says.

The pests — also called bush, cattle or scrub ticks — are tiny and light brown. Female ticks are able to reproduce on their own, and only one tick is needed to populate an area. 

To survive, they attach to and feed on their hosts, which can be humans, pets, wildlife or livestock.

The Asian longhorned tick is native to East Asia and is uncommon in the Western Hemisphere, according to the USDA. Although the first case of the Asian longhorned tick in the U.S. was discovered in Hunterdon County, New Jersey, in late 2017, the tick "likely" arrived in the U.S. in 2010 or earlier, according to the USDA Inspection Service.

It's unclear exactly how and when the tick was introduced to the United States, "but one thing is certain: it likely entered the country via domestic pets, horses, livestock, or humans," the inspection agency said.

Where has the Asian longhorned tick been found?

A USDA map shows that the tick has been found in the Northeast, Midwest, and Southeast United States, as far west as Oklahoma.

The first confirmed sighting of the Asian longhorned tick was in Michigan earlier this year.

What diseases do Asian longhorned ticks carry?

Species of the tick in the U.S. have been discovered to carry Theileria orientalis, which is a pathogen that causes disease in cattle, according to Michigan's agriculture department. 

Asian longhorned ticks are also able to cause diseases such as Rocky Mountain spotted fever, heartland virus and Powassan virus, although they have not been confirmed to carry them in the U.S. outside of a lab setting, according to Michigan's agriculture department.  

Large infestations of the tick can harm animals, and even kill them. 

"Unlike other ticks, a single female Asian longhorned tick can produce offspring-1,000 to 2,000 eggs at a time-without mating. That means individual animals could each host hundreds to thousands of ticks," the Department of Agriculture says. "This can cause great stress on a heavily infested animal and result in reduced growth and production. A severe infestation can kill the animal from excessive blood loss."

How to prevent Asian longhorned ticks People can pick up ticks in their yards, while walking their dogs, or while gardening. Officials recommend that people check their bodies and clothing upon entering their homes and immediately remove any ticks.

The Centers for Disease Control and Prevention (CDC) says people can prevent tick bites by treating clothing and other items, such as boots and camping gear, with products containing 0.5% permethrin. The CDC also recommends using certain insect repellents registered with the Environmental Protection Agency (EPA). Officials say it's also helpful to keep yards and pastures free of brush and to use gravel or mulch along borders to reduce tick habitat. Regular tick treatment is recommended for pets and livestock. Officials urge animal owners to check for ticks regularly and consult a veterinarian about preventative measures.