Researchers have identified the Asian longhorned tick in Maine, marking the furthest northeastern appearance of the invasive species in the U.S. The discovery was confirmed in July by the University of Maine and state conservation officials, they announced Monday.
Native to East Asia, the Asian longhorned tick is known to spread diseases such as spotted fever in its home range. It was first detected in the U.S. in New Jersey in 2017 and has since spread to over 20 states, primarily across the eastern part of the country. While its exact method of arrival remains unclear, experts believe it may have been introduced via pets, livestock, or wildlife.
“This discovery underscores the critical importance of continued tick surveillance in Maine,” said Griffin Dill, director of the University of Maine 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 juvenile tick was collected in southern Maine, and follow-up searches in the area have not revealed additional specimens. Since it was not yet an adult, the tick was incapable of reproducing, researchers said.
Interestingly, the species hasn’t been found in neighboring New Hampshire. Dill told Maine Public Radio that its sudden appearance in Maine could be due to migration via birds or travel with out-of-state pets.
Asian longhorned ticks feed on a wide range of animals, including livestock and humans. They are particularly concerning because female ticks can reproduce without mating, meaning a single tick can spark a local outbreak.
The lab emphasized that research is ongoing to understand the tick’s potential to transmit diseases in Maine and elsewhere in the U.S. Ticks remain a serious health concern in the Northeast, where other species, such as the blacklegged (deer) tick, are known carriers of Lyme disease.
Officials are urging residents to stay alert for unfamiliar ticks. According to Dill, this species can appear in unusual places, including lawns, pastures, and even gravel areas around buildings—places where people don’t typically expect to find ticks.