The Asian longhorned tick has emerged as the first invasive tick species in the United States in 80 years, according to the Centers for Disease Control and Prevention.
The parasite, known scientifically as Haemaphysalis longicornis, was first found in 2017 on a sheep in New Jersey. Asian longhorned ticks have since spread west and been collected in 16 other states: Arkansas, Connecticut, Delaware, Georgia, Kentucky, Maryland, Missouri, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia and West Virginia. The tick is native to China, Japan and Korea.
Asian longhorned ticks are parthenogenic, which means the female does not need a male to lay viable eggs. Each adult female can spawn up to 3,000 clones in a few weeks without mating.
The ticks can transmit serious diseases such as Theileria orientalis, Rickettsia rickettsii, Heartland virus and Powassan virus. However, no special precautions are advised.
“At this point, personal protection against ALTs is the same as what we recommend for other human biting ticks,” said Neeta Connally, Ph.D., who leads Western Connecticut State University’s Tick Lab team. “They do commonly feed on dogs, so treating pets with an effective tick-preventative product all year long is also important.”
The ticks’ westward expansion is thought to be caused by the travel of cattle, horses, pets and wildlife. Deer, especially, are excellent hosts for numerous tick species.
According to the Entomological Society of America, “The confluence of environmental, ecological, sociological and demographic factors has created a near perfect storm, leading to more ticks in more places throughout North America.”
Recent projections suggest that the Asian longhorned tick has the potential to inhabit most of the Eastern U.S. and the coastal Pacific Northwest.
ALTs, in their various life stages, are active from spring through fall — nymphs from late spring through midsummer, adults from June to August, and larvae in August and September.
Surveillance programs have been initiated in areas where ALTs are present or may soon appear. Some experts think that keeping grass short and removing woody debris from lawns and pastures might reduce Asian longhorned tick populations.