Asian Longhorned Tick

Several tick species spread diseases to humans, including American dog ticks (Dermacentor variabilis), blacklegged ticks (Ixodes scapularis), western blacklegged ticks (Ixodes pacificus), and lone star ticks (Amblyomma americanum). With international trade transporting arthropods among continents, warming temperatures expanding habitable ranges, changes in land use, and increases in host populations, invasive tick species are a growing problem in North America. And, when invasive tick species do become established, they raise the concern of spreading diseases to humans, pets, and livestock. Over 100 tick species from other countries have arrived in the continental U.S. already.

A species of exotic tick arrived in Ohio in 2021 in such huge numbers that their feeding frenzy on a southeastern farm left three cattle dead of what researchers believe was severe blood loss. The scientists from The Ohio State University have reported in the Journal of Medical Entomology on the state’s first known established population of Asian longhorned ticks, and are now conducting research focused on monitoring and managing these pests.

Ohioans are encouraged to help with research efforts: People who think they’ve spotted an Asian longhorned tick can email ticks@osu.edu for instructions on how to collect the specimen and send it to Ohio State scientists as part of ongoing surveillance. To date, the lab has received Asian longhorned ticks from residents of 11 Ohio counties. More information about spotting Asian longhorned ticks and preventing tick exposure is available on Ohio State’s Bite Site hosted by the College of Food, Agricultural, and Environmental Sciences Knowledge Exchange.

The Asian Longhorned tick (ALT), which was first discovered in the United States in 2017 has now be found in 19 states including Virginia. Currently, there are 38 Virginia counties with established ALT populations. As ALT populations have increased, a concern for the health of livestock in affected areas has increased as well. ALT is a vector for the parasite Theileria orientalis Ikeda which can cause theileriosis in livestock, including cattle.

The Centers for Disease Control and Prevention is working with public health, agricultural, and academic experts to understand the possible threat posed by the spread of the Asian longhorned tick (Haemaphysalis longicornis) in several U.S. states since its discovery in 2017, according to today’s Morbidity and Mortality Weekly Report. "The full public health and agricultural impact of this tick discovery and spread is unknown," said Ben Beard, Ph.D., deputy director of CDC's Division of Vector-Borne Diseases. "In other parts of the world, the Asian longhorned tick can transmit many types of pathogens common in the United States. We are concerned that this tick, which can cause massive infestations on animals, on people, and in the environment, is spreading in the United States."

Ticks may not seem dangerous, but they can cause disease and even death in livestock and pets. There are hundreds of tick species in the world, about 10 percent of these species are found in the United States. Now there’s one more to watch out for. In 2017, the U.S. Department of Agriculture (USDA) confirmed the presence of the Asian longhorned tick (Haemaphysalis longicornis). It probably arrived in the United States in or before 2010. Exactly how or when is unknown, but one thing is certain: it may have entered on domestic pets, horses, livestock or people. While we know the impact of this tick in other parts of the world, we are still studying how they may affect U.S. agriculture, and our environment.
See also: APHIS in Action to explore plant and animal health or wildlife damage management data and Interactive Story Maps