Who let the ticks in?


There’s a new tick in town, and nobody’s sure how it got here.

A team of researchers at Oklahoma State University’s (OSU) Center for Veterinary Health Sciences has confirmed the existence of an exotic species of tick in the United States.

The particular tick they examined was found on a dog in Arkansas. Classified as a nymphal longhorned tick, or bush tick, Haemaphysalis longicornis was discovered through a national tick surveillance project being conducted by the OSU team, led by Susan Little, DVM, PhD, DACVM (Parasitology). The lab confirmed the morphologic identification through gene sequencing and reported the finding to the US Department of Agriculture.

According to Little, the team wasn’t exactly blown away by the findings.

“We knew to be on the lookout for this tick given recent reports in New Jersey, Virginia, and West Virginia,” said Little. “We are very glad we were able to assist on efforts to understand the current distribution of this new species.”

In the New Jersey case, a resident brought tick samples to the Hunterdon County Health Office after shearing Hannah, her 12-year-old Icelandic sheep, and discovering hundreds of ticks swarming on her skin.

Originally from East Asia, the longhorn tick successfully established itself in other areas of the world, including Australia, New Zealand, and now, perhaps the eastern United States. It feeds on cattle, small ruminants, horses, dogs, cats, people, and several common wildlife species.

According to a report in the journal Entomology Today, H. longicornis is a unique species of tick because of its capacity for parthenogenesis (reproduction without fertilization). In parthenogenesis, females produce offspring that are more or less clones of herself. And that’s what appears to have enabled the infestation in New Jersey; among 27 adults, 41 nymphs, and 1,058 larvae collected on the site, just a single specimen was male.

In the United States, H. longicornis has been intercepted at quarantine stations on several occasions, and then only in small numbers. But a potentially established population of multiple life stages has never before been documented in the US.

None of the ticks collected in New Jersey were found to be carrying disease, according to the New Jersey Division of Fish and Wildlife.

Little’s team is doing ongoing surveillance to see where else H. longicornis might turn up in North America and what diseases—if any—they may be transmitting. And the team is happy to have your help. If you find unusual ticks on animals, please feel free to submit them to OSU’s veterinary center for identification.

Most modern tick-control products are effective against this tick in other areas of the world.

Photo credit: © iStock/adogslifepohoto

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