As if there weren’t enough ticks in the U.S., another species from Asia has been found in rapid occurrences in the past few years.

The Asian longhorned tick—Haemaphysalis longicornis (H. longicornis)—is usually never found in the Western Hemisphere. However, the first reported sighting of the foreign tick in the U.S. was in 2017, according to the Centers for Disease Control and Prevention (CDC). Since then, sightings have rapidly increased on the eastern side of the country.

The Asian longhorned tick originates from East Asia. It is characterized by its outstretched front legs appearing to resemble Texas Longhorn cattle’s horns. Adults are brown in color without distinct markings or colorings, according to Pennsylvania State University (PSU) Extension.

The Asian longhorned tick has three life stages: larva; nymph; and adult, and infests a different host during each stage.

What makes this species different from others is the female’s ability to reproduce without a male, allowing rapid reproduction. Females generally tend to lay their eggs during late spring or early summer, according to PSU Extension. Hatched larvae will crawl onto vegetation to find a host in late summer and once full of blood, will fall off and overwinter. Molting into a nymph the following spring, the tick will find another host. After dropping off for the last time, the tick will molt into an adult and find its final host, producing up to 2,000 eggs over a period of only a couple of weeks.

The ticks may be confused with rabbit or bird ticks, but if identified on other hosts, they are likely to be H. longicornis. Nymph ticks may also be confused with immature lone star ticks.

The adults tend to feed on the ears, brisket, neck, shoulders, inside flanks, and groin areas of animals.

U.S. sightings

The first sighting of the tick in the U.S. was in New Jersey on a sheep in 2017. Since then, there have been 11 states with confirmed populations, USDA Animal and Plant Health Inspection Service Spokeswoman Joelle Hayden told WLJ.

Virginia now has the most infested counties, with 24 confirmed so far, the North Carolina Cooperative Extension said in a released statement.

States with recorded infestations as of June 24 include Arkansas, Connecticut, Kentucky, Maryland, North Carolina, New Jersey, Pennsylvania, Tennessee, Virginia, and West Virginia.

There’s a new tick in town

Two Asian Longhorned ticks atop a dime. The smaller of the two ticks on the left is a nymph. The larger tick is an adult female. Males are rare. This tick can reproduce asexually. 

The tick is likely to be established in the U.S. and is now considered an invasive pest. Animals found hosting the tick include sheep, goats, dogs, cats, horses, cattle, deer and other wildlife, and humans.

In other countries, the Asian longhorned tick can transmit bovine theileriosis or babesiosis, blood infections that can lead to fever and anemia.  Although Asian longhorned ticks in the U.S. have not been found carrying these diseases, Hayden said the agency is continuing to closely monitor the situation.

Although not yet found to be carrying the diseases from its home countries, the tick still poses a threat to both livestock and humans.

One North Carolina rancher in Surry County had five cattle die from acute anemia by ticks; the cattle were drained of blood by the rapid infestations. A young bull was brought into a diagnostic lab with more than 1,000 ticks on his body.

A May 2019 study from a collection of research institutions described a man in New York who removed the Asian tick from his leg after working on his lawn. Although he did not develop an infection, researchers surveyed his yard and the nearby park in open sun for additional populations and found the first known collections of the species in New York. Prior to this incident in June 2018, there was no record of a human being bit in the U.S.

Hayden recommends completing regular tick treatments for animals and consulting a veterinarian for preventative products to use. Livestock should be checked regularly for ticks and any unusual looking ticks should be reported to a local health department or state animal health official. Keeping grass and weeds trimmed and brush cleared are important tick prevention practices.

People should take care to wear long-sleeved clothing while outside and apply insect repellant containing DEET.

“Agencies involved in animal and public health are working together to monitor the distribution of the tick, test for pathogens, and treat for the tick when necessary to potentially stop the spread to new areas in the U.S.” Hayden said. — Anna Miller, WLJ editor

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