Story copied from CNN: https://www.cnn.com/2018/12/13/health/asian-longhorned-tick-us-spread-study/index.html
(CNN)The Asian longhornedtick most likely began invading the United States years ago. Now found in ninestates, the tick may soon occupy a large swath of eastern North America as wellas coastal regions of the Pacific Northwest, according to research published Thursday in theJournal of Medical Entomology.
“This tick can bite humans, pets, farm animals and wildlife,” said Ilia Rochlin, author of the study and an entomologist and researcher associated with the Rutgers University Center for Vector Biology.
Until recently, this species was found only in China, Japan, Korea and southeastern Russia as well as in parts of Australia, New Zealand and the Pacific islands. Then, in 2017, the first established Asian longhorned tick population was discovered in New Jersey, followed by detections in Virginia, West Virginia, Pennsylvania, North Carolina and Arkansas.
Although the tick is capable of causing infectious disease, no cases of illness, either in humans or in animals, have been reported in the United States.
“There is a good chance for this tick to become widely distributed in North America,” Rochlin said. “Mosquito control has been very successful in this country, but we are losing the battle with tick-borne diseases.”
Unusual reproductive abilities
Dina M. Fonseca, director of the Center for Vector Biology, a Rutgers professor of entomology and co-author of a previous report published by the US Centers for Disease Control and Prevention, explained the Asian longhorned tick’s strange capacity to reproduce asexually.
“These ticks are parthenogenetic, which means that females create diploid eggs (with a full set of the mother’s DNA) that develop into adults without needing the DNA of a male,” she wrote in an email. (Fonseca did not contribute to the new study.)
Of nearly 700 species of “hard” ticks — of which the Asian longhorned tick is one — only a handful are known to be parthenogenetic. “So it is a rare ability but not exceptional,” said Fonseca. This unusual method of creating clones means it is possible for the tick to cause “massive” infestations of its hosts. “We have seen very large numbers on livestock as well as on dogs.”
One of the diseases Asian longhorned ticks can transmit is severe fever with thrombocytopenia syndrome, a hemorrhagic illness that has recently emerged in China, South Korea and Japan, according to the previous CDC report.
This syndrome, which also causes nausea, diarrhea and muscle pain, results in hospitalization for most patients and leads to death for up to nearly a third of those infected. This possibility is a concern because a close relative of the illness, the Heartland virus, circulates in Midwestern and Southern states, Rochlin noted.
Two Asian longhorned ticks: a nymph or immature tick at left and an adult female.
In Australia and New Zealand, the Asian longhorned tick has transmitted theileriosis to cattle. Also called “bovine anemia,” the illness causes lethargy, lack of appetite and, in pregnant cows, spontaneous abortion or stillbirth. “In some regions of New Zealand and Australia, this tick can reduce production in dairy cattle by 25%,” the CDC report says.