Three longhorned ticks: from left, a fully engorged female, a partial engorged female and an engorged nymph.
Three longhorned ticks: from left, a fully engorged female, a partial engorged female and an engorged nymph. (Jim Occi / Rutgers University via AP)

A longhorned tick was found on a white-tailed deer in Washington County last month — the first sighting of this tick species this season.

A test by the National Veterinary Services Laboratories confirmed the tick, also known as the Haemaphysalis longicornis tick, the East Asian tick and the bush tick.


The tick, which is not native to Maryland and can be mistaken for more common types of ticks, was found July 27 in the Western Maryland county.

Frequent rain and flooding in May and June have helped mosquito populations multiply across Maryland — to three times their normal early summer numbers. The state has increased spraying to limit the public health threat and nuisance.

Hard to see with the naked eye, the brown-colored tick has distinctive “horns” that can be seen under a microscope, according to the Maryland Department of Natural Resources. It can reproduce asexually and can lay anywhere from 800 to 2,000 eggs after feeding on a host.

If too many of this species of tick attach to an animal, it could cause stunted growth, decreased production and major blood loss, and has the potential to spread disease, Dr. Michael Radebaugh, the Maryland Department of Agriculture’s state veterinarian, said in a statement.

Officials from the departments of agriculture health and natural resources are cautioning residents to protect livestock, pets and fellow humans from the tick.

The spread of illnesses from mosquito, tick Lyme disease and other illnesses spread from mosquito, tick and flea bites more than tripled from 2004 to 2016 in what the Centers for Disease Control has called an increasing public health risks.

“In order to keep livestock and pets safe, we encourage owners to check their animals for a high concentration of tick bites or abnormal ticks,” Radebaugh said. “This species of ticks are known to cling to hosts in high numbers.”

The longhorned tick has been found in eight states: New Jersey, West Virginia, Virginia, Arkansas, North Carolina, New York, Pennsylvania and now Maryland. The tick can carry several diseases, but none in the United States have been found to carry infectious pathogens.