Asian longhorned ticks were recently found in Michigan for the first time. A team of students and researchers at Calvin University discovered the species in a routine environmental surveillance check in Berrien County.
William Miller is an Assistant Professor of Biology at Calvin University and a certified wildlife biologist. He said the discovery was surprising, because ticks are usually found through veterinary animal examinations.
He said he had to look closely at the tick through a microscope to confirm that it was an Asian longhorned tick.
The Michigan Department of Agriculture and Rural Development said this species of tick is very small; females grow to the size of a pea when they're full of blood, but other life stages of the tick are about the size of a sesame seed or smaller.
MDARD said the species has spread to 21 other states since being first spotted in New Jersey in 2017.
William Miller said both MDARD and the Michigan Department of Health and Human Services (MDHHS) viewed the emergence of the Asian longhorned tick in Michigan as a problem that would surface eventually.
Miller said that the closest states with populations of this tick species are Indiana and Ohio. Miller said the ticks could have traveled to the Michigan area through migratory or highly mobile species such as white-tailed deer and birds. He said people bringing pets or their farm animals to different areas could have played a role in the spread of the species as well.
Miller said this species can easily invade new areas, and once the ticks are in a new place, it is easy for them to reproduce. That's because they do not require males to reproduce. In a process known as parthenogenesis, a single female can lay viable eggs on her own and seed a new population.
Miller said while this tick species has the potential to transmit pathogens associated with human diseases, there is no current epidemiological link from exposure to this tick and subsequent diseases in the United States. MDARD said this tick species is not known to carry Lyme disease.
Miller said this species of tick doesn't usually bite people, but they are huge agricultural pests, especially for cattle.
“The primary concern with this species is its role as an agricultural pest,” Miller said. “Since they can reproduce quickly and establish large populations relatively fast, we can often see high infestations.”
While it is difficult to manage the spread of these ticks, it is important to provide as much info as possible to relevant stakeholders so they can make informed decisions on how to manage their particular areas, he said. This is especially crucial during the early stages of tick development, Miller said.
MDARD recommends regular tick treatments for animals.
Miller said the number of ticks in Michigan varies over the years as populations fluctuate, but this year he said his team has seen a higher density of ticks.
He said to avoid encountering ticks, you can stick to established trails, regularly do tick checks when you come in from outdoors, and use EPA regulated repellents. This can also limit the possibility of someone inadvertently picking up a tick and taking it to a new location.
“We encourage folks in Michigan to become tick aware, but not tick afraid,” Miller said.
