Kentucky Correspondent

LEXINGTON, Ky. – One of the weirder – and dangerous – species of ticks has found its way into the Bluegrass State. The tick is known to be lethal to cattle and pets, having caused “significant losses” to cattle in New Zealand and Australia. The tick has been found in small numbers on elk in Martin County and black bear in Floyd County. It was found in large numbers on a bull in Metcalfe County in the south-central part of the state. It is a species which is also able to multiply without breeding.

According to a recent study by Rutgers University published in the journal Zoonoses and Public Health, an invasive population of Asian longhorned ticks in the United States likely began with three or more self-cloning females from northeastern Asia. Although this species transmits serious illnesses to people and animals in other countries, experts don’t know whether the tick populations in the United States will make people sick, according to the U.S. Centers for Disease Control and Prevention. Once in the United States, the ticks were most likely carried from place to place by wildlife, livestock and pets. The researchers said dogs in particular are effective carriers that allow ticks to cross state and international lines.

“Many countries require dogs to be treated for ticks and other parasites before entering the country, but the United States does not. We urge greater awareness of this issue to prevent future exotic tick introductions,” said Dina Fonseca, the study’s senior author and director of the Rutgers University Center for Vector Biology.

The small redish-brown species has two forms: one with males and females, and one with self-cloning females which lay eggs without needing to mate, a process called “parthenogenesis.” The self-cloning tick, free from the need to look for mates, is especially likely to thrive and spread. A single female can establish a fast-growing population. This type entered Australia and New Zealand in the early 1900s and now causes significant losses in the cattle industry.

“The Metcalfe County ticks were submitted by a veterinarian who answered a call about a bull so infested that it was showing signs of severe fatigue,” said Anna Pasternak, a University of Kentucky (UK) entomology graduate student who manages the Kentucky Tick Surveillance Program. “With the first two findings being in Eastern Kentucky, the Metcalfe County finding is particularly troubling as it means the tick may have already spread farther across the state.”

The Asian tick was first found in 2017 in the United States. In addition to Kentucky, it has also been confirmed in Arkansas, Connecticut, Delaware, Maryland, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, Tennessee and West Virginia. Among a plethora of wild animals, it has also been observed to prey on cattle, sheep, goats, horses and chickens. As it gets further established in the state, the tick is expected to have adverse effects on the state’s deer and wildlife population. 

“This tick is an aggressive biter and frequently builds intense infestations on domestic hosts that can cause stress, reduced growth and severe blood loss,” said Jonathan Larson, extension entomologist at UK. “One reason for their rapid buildup is that the female ticks can lay eggs without mating. It only takes a single fed female tick to create a population of ticks. Potentially, thousands can be found on an animal.”

Individuals who find a usually large number of ticks on their pet or livestock should contact their local veterinarian. Those who find single ticks they think might be an Asian longhorned tick should work with their county extension agent for agriculture and natural resources to submit the sample to UK entomologists for positive identification.