PORTLAND, Maine (AP) — Researchers have confirmed the presence of an invasive species of tick in Maine for the first time, marking the farthest northeast in the United States the pest has been discovered.

The University of Maine and state conservation officials said Monday they confirmed the presence of the Asian longhorned tick in the state in July. The tick is native to east Asia, where it is capable of spreading tickborne infections such as spotted fever.

The tick was first confirmed in the United States in New Jersey in 2017 and it has since spread to more than 20 states, clustering mostly around the eastern third of the country. Exactly how the tick arrived in the country isn’t certain, but public health officials have cited possible routes of entry including on pets and livestock.

“This discovery underscores the critical importance of continued tick surveillance in Maine,” said Griffin Dill, director of the UMaine Extension Tick Lab. “While this appears to be an isolated case, we are closely monitoring the situation and coordinating with state and federal partners.”

The tick specimen was not yet an adult and it was collected in the southern part of the state, the lab said in a statement. Follow-up surveillance didn’t turn up any additional specimens in the surrounding area, the lab said.

Asian longhorned ticks feed on numerous animals, including cattle and humans. They pose a challenge for pest control authorities because female ticks of the species can reproduce without mating, which means a single individual can create an infestation, the lab said. The specimen found in Maine could not reproduce yet because it was a juvenile, the lab said.

Research is still going on to determine the tick species’ ability to spread pathogens in Maine and elsewhere in the U.S., the lab said. Ticks are a major public health concern in the Northeastern U.S., where another species, the blacklegged or deer tick, spreads Lyme disease.

In the meantime, the public can prevent tick bites by taking steps such as conducting rigorous checks for them, avoiding overgrown vegetation and wearing protective clothing, public health officials said.