Kentucky’s temperate climate is an ideal habitat for a new invasive tick species that clusters on livestock, reproduces without mating and remains a potential vector for disease.
The Asian longhorned tick is the first new tick species detected in the United States in the last several decades and its range is growing rapidly.
“This tick is kind of playing by unfair rules in that it can reproduce asexually,” said Kelly Giesbrecht, Kentucky’s state public health veterinarian. “It’s like, ‘Mother Nature, that’s just not fair.’”
First discovered on the East Coast in 2017, researchers have already identified the tick species in 11 states stretching from New York to Arkansas. And Kentucky is right in the center of its known distribution area.
It also happens that Kentucky’s forests, rolling hills, farms and pastures make a comfortable home for the critter that’s similar to its native home in Eastern Asia.
“We’ve all been waiting for it to show up because we are surrounded by it in other states so that it skipped over Kentucky is unlikely,” Giesbrecht said.
Kentucky researchers first found the Asian longhorned tick on an elk in Martin County in July of last year then again in the same county in April of this year, Giesbrecht said.
The ticks are characteristically brown and difficult to distinguish from other species, which may be one reason why more haven't been identified.
They’re attracted to large herd animals including deer, elk and cattle where they cluster in the dozens to the thousands, engorging themselves on the blood of their hosts.
And because of their unusual ability to reproduce without mating, about 99 percent of all the Asian longhorned ticks discovered in the U.S. are female.
In China, Japan and Korea, scientists have found the tick can carry a virus that causes severe fevers. So far researchers haven’t found any similar diseases in the U.S. population of ticks.
But researcher Ilia Rochlin with the Rutgers Center for Vector Biology said the virus found in Asia is similar enough to another U.S.-based virus that the tick species could become a new vector for disease.
“So now you take this vector that can transmit a very similar virus and you put in the same area as the heartland virus then the outcome is very unclear, but it definitely should be closely monitored,” Rochlin said.
For now, the species appears to be more interested in large herd animals than humans, but it remains to be seen whether that will change, he said.
Giesbrecht, Kentucky's public health veterinarian, has recently begun to join calls with surrounding states and the U.S. Centers for Disease Control and Prevention to learn more about the invasive species.
She said Kentucky’s research into the Asian longhorned tick is only just beginning and that more funding will be necessary to keep that research going.
“Right now there is a giant question mark surrounding this tick and it’s going to take time,” Giesbrecht said.
