The longhorn tick (Haemaphysalis longicornis), an exotic East Asian tick, has never previously established a population in the US. It is a known serious pest of livestock in the Australasian and Western Pacific Regions where it occurs. It is an aggressive biter and frequently builds intense infestations on domestic hosts causing great stress, reduced growth and production, and exsanguination. As the tick can reproduce parthenogenetically (without a male), a single fed female tick can create a population. It is also a known/suspected vector of several viral, bacterial and protozoan agents of livestock and human diseases.
Being a three-host tick, this tick has the ability to spread pathogens among a diverse host range, on which it feeds side-by-side with other tick species. The detections detailed here are the first time this tick has been seen out of quarantine in the United States. The establishment of this tick species is unprecedented in recent United States history regarding its geographic scope and might only be compared back to the spread of cattle fever ticks in the late 1800s.
Recent highlights of tick detections:
On June 25, 2018 NVSL confirmed a larval H. longicornis upon reexamination of a sample submitted in 2010 from a white-tailed deer from Tyler County, WV. This correct identification back dates the first collection of H. longicornis in the US to August 31, 2010 and is the fourth WV county.
On June 19, 2018 NVSL confirmed multiple H. longicornis from a dog in both Putnam and Ritchie County, WV. These are the second and third WV counties with confirmed infestations.
On June 5, 2018 NVSL confirmed a H. longicornis from Benton County, Arkansas submitted from a dog through a research project at Oklahoma State University. Although, a sample was not available for site identification at NVSL; NVSL was able to confirm via a photograph and via molecular typing to H. longicornis at Oklahoma State.
Four states (Arkansas, New Jersey, Virginia, and West Virginia) have NVSL confirmed infestations with H. longicornis. Both New Jersey and Virginia have activated a state incident management team (IMT). However, the NJ IMT was deactivated on June 14, 2018.
A sample submitted from a dog from Union County, NJ (Watchung Reservation) has backdated the first detection of the longhorned tick to 2013 (from the previously thought May of 2017).
The current host list from this introduction includes: dog, cow, goat, sheep, white-tailed deer, opossum, raccoon, and horse.
Download the full USDA report here.
Specific questions can be addressed to:
Lee C. Jones
Wildlife Health office
USFWS-Natural Resource Program Center
10 E. Babcock, Rm 105
Bozeman, MT 59715