Invasive tick new to East Tennessee found on animals
KNOXVILLE, Tenn. — There’s a new kind of creepy-crawly to look out for in East Tennessee this summer. The invasive Asian longhorned tick, which can reproduce without mating, has been found on animals in Union, Roane and Knox counties.
The parasite was first discovered about two years ago on sheep in New Jersey.
“We kind of found the tick accidentally, and that’s led a lot of people to question what ticks are here and if there are others missing from what we know of ticks in the country,” said Dr. Rebecca Trout-Fryxell, a medical and veterinary entomologist at the University of Tennessee Institute of Entomology and Plant Pathology.
Trout-Fryxell is part of a team of multiple agencies studying the tick: University of Tennessee Department of Agriculture, Tennessee Wildlife Resources Agency, the state Health Department, and the U.S. Department of Agriculture.
“We got together and said well, we’re just going to check all the ticks we can,” she said. “What we’re really trying to do is get a general assessment of what ticks are present in Tennessee.”
There are no reports of the tick farther south than Tennessee. It has also popped up in Arkansas, Connecticut, Kentucky, Maryland, North Carolina, New Jersey, New York, Pennsylvania, Virginia, and West Virginia, according to the Centers for Disease Control and Prevention.
Outside of the United States, the ticks have been shown to carry multiple infections and viruses, but to date, no infectious agents have been identified in the Asian longhorned ticks found in the United States.
The Centers for Disease Control has started colonies of the ticks to test whether or not they are able to carry and transmit pathogens found in the United States, like Lyme Disease or Rocky Mountain Spotted Fever.
So far, only two people have been bitten in the United States, and Trout-Fryxell said she has found the ticks crawling across her body while collecting them in the field, but has never been bitten.
“They’re feeding on other things; it doesn’t seem like they’re really choosing to feed on humans,” she said, adding that many arthropods feed on specific species, but the Asian longhorned tick has been found on a hawk and 17 different species of mammals, though on very few humans.
Dogs, cattle, white-tailed deer and small ruminants like sheep and goats may be at risk of being bitten though.
Scientists don’t yet know how the invasive tick will survive in Western hemisphere habitats or how the tick moves to new areas, though Trout-Fryxell said it’s likely they came in on an infested animal.
“We don’t know where it came from, though it’s suspected to be from one of the areas the ticks live now, like southeast Asia,” said Trout-Fryxell. The ticks are also found in New Zealand and Australia.
So far, the University of Tennessee has only recovered female ticks in the field, but the females collected have both male and female reproductive organs.
Most ticks can lay between to 2,000 to 4,000 eggs per year, though it takes each egg two to three years to develop into a reproducing adult. But, Trout-Fryxell said, the Asian longhorned tick has been known in other parts of the world to develop from egg to adult much faster.
“And because it doesn’t have to find a mate to reproduce, the population can expand really quickly,” she said, adding that scientists don’t know if an explosion of the invasive ticks in the hemisphere could displace native tick populations.
“It will likely be a thing where when we find one in a location, we’ll find a lot of them.”
Trout-Fryxell said if you find a tick outside or on an animal, you can participate in the study by sending it to the University of Tennessee.
To do so, place the tick in a zip-close bag labeled with the date, location it was found and the animal the tick was found on, and mail it to 370 Plant Biotechnology Building, 2505 E.J Chapman Drive, Knoxville, Tennessee 37996.
You can also submit it to your local county extension agent. Entomologists analyze each tick presented with the proper information, but only respond to submitters if the tick is indeed an Asian longhorned tick.
If a tick is found on a human, Trout-Fryxell said after removing the tick with its mouthparts, it’s best to keep the labeled zip-close bag in your freezer to present to a medical professional if you begin to have symptoms of tickborne illness.
“Again, it’s important not to be an alarmist on this,” she said. “This tick is not very common right now. Ticks like the lone star tick are more common.”