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.”