Asian longhorned tick identified in Oklahoma

Originally from eastern Asia, the Asian longhorned tick, Haemaphysalis longicornis, has established itself in Australia, New Zealand, several Pacific Region island nations, and now the United States. Detection of the tick in 2017 on a sheep in New Jersey was thought to be the first recognition of the tick in the United States, however, upon further analysis the tick was found in samples from as early as 2010.

In 2018, researchers at the Oklahoma State University College of Veterinary Medicine identified the tick species on a dog from Arkansas. In the summer of 2024, the tick was identified on cattle in Mayes County in northeast Oklahoma.

The Asian longhorned tick parasitizes multiple species including humans, pets, livestock and wildlife, including birds. Relatively small in size as compared to native ticks, it is a three-host tick. It spends 90% of its life off its host. The larvae, often referred to as seed ticks, feed on smaller animals, while the nymph and adult stages target larger animals, including humans and cattle. The four most common animals this tick has been found on within the United States are dogs, white-tailed deer, raccoons and cattle.

The female tick can reproduce without mating and may produce 1,000 to 2,000 eggs at a time. A single female tick has the potential to create an established population in a newly introduced location in two to three weeks.

The tick does not move far from available hosts when transitioning between life stages. High humidity areas regularly visited by grazing livestock, such as wooded or tall grass areas, will more likely sustain the tick. Dehydration is one of the most limiting factors in tick populations.

Severe infestations of the Asian longhorned tick in cattle can lead to death from the stress of excessive blood loss. Production losses, including decreased milk production and growth are substantial. The Asian longhorned tick has also been recognized as a vector for multiple diseases of both humans and animals including viral, bacterial and protozoan agents.

In other countries, the tick is the primary vector of Theileria orientalis Ikeda genotype in cattle . The protozoan causes clinical signs like anaplasmosis-anemia, fever, lethargy, jaundice and death. The mortality rate for cattle infected with Theileria orientalis Ikeda genotype varies from three to 90%. Theileria oreintalis Ikeda genotype has been identified in the United States, but as of this time not in Oklahoma. Research into the connection between the Asian longhorned tick and Theileria orientalis Ikeda genotype in the United States is ongoing.

Treatment and preventative measures for the Asian longhorned tick are similar to those used currently for populations of ticks in the United States. Most modern tick control products are effective against this tick. Producers should select products as directed by their veterinarian. Pasture management programs may be effective control measures. Controlled burning and mowing the pasture boundaries adjacent to wooded areas may also be useful.

If producers suspect that a tick is different from other ticks seen previously in their area, then the tick should be submitted for identification. Veterinarians, as well as OSU Extension Educators, can assist with the submission process. Samples should be submitted for identification to the Oklahoma Animal Disease Diagnostic Laboratory.

The best method for tick submission is to place the tick into a sealable glass vial with 70% ethanol. The sample should include where the tick was collected (GPS coordinates or street address), type of animal or if it was collected from a person, and the date of collection. All of this will be required for identification. If a tick is presumed to be the Asian longhorned tick, then the Oklahoma Department of Agriculture, Food & Forestry will be notified as to the location of the positive tick sample.