It would be an understatement to say the Asian longhorned tick (Haemaphysalis longicornis) is a prolific breeder because the female can copy itself through asexual reproduction, or reproduce sexually, laying 1,000-2,000 eggs at a time.
According to a new Columbia University study published in the journal Emerging Infectious Diseases, the invasive tick species may pose a greater risk in New York than previously thought.
The ticks are typically found in grass in addition to the forested habitats preferred by the deer tick, and this has added a new complication to public health warnings, and they may have come too late because the population has expanded so rapidly.
“The fact that longhorned tick populations are so high in southern Staten Island will make control of this species extremely difficult,” says Meredith VanAcker, a member of Diuk-Wasser’s lab who collected the data as part of her Ph.D. thesis. “And because females don’t need to find male mates for reproduction, it is easier for the population to spread.”
The Asian longhorned tick – what we know
The tick was identified for the first time on a farm in Ames, Iowa in Hunterdon County on November 9, 2017. Livestock and the property were treated to eliminate the ticks. There has been ongoing surveillance of the surrounding forests.
At the time, the tick was not known to be present in the U.S., although there are records of at least a dozen previous collections of this species in the country on animals and materials presented for entry at U.S. ports.
Easily confused with other tick species, especially the rabbit tick, H. longicornis – also known as a bush tick – is known to carry several diseases that infect hogs and cattle, as well as humans in Asia. As of March 11, 2019, ticks examined in the U.S. do not carry any infectious pathogens.
Since the initial finding in November 2017, the longhorned tick has been found in eight states, including New Jersey, Virginia, West Virginia, North Carolina, Pennsylvania, New York, Arkansas, and most recently, Maryland.
Because this tick can reproduce by parthenogenesis, asexual reproduction, it is especially concerning. When the first 100 or so ticks from the Ames, Iowa farm were examined, health officials found only one male. And the female tick will lay eggs after she has fed on her host, without any help from a male tick.
“The concern with this tick is that it could transmit human pathogens and make people sick,” Columbia researcher Maria Diuk-Wasser, whose lab led the study and comprehensive “tick census” on Staten Island, said in a statement.
The CDC is suggesting that people who think they have found one of the ticks should remove the tick from any person or animal it is found on, preserve it a jar or ziplock bag and contact their local health department for advice.
