The Illinois Department of Agriculture has reported that the Asian longhorned tick (H. longicornis) has been detected in the State.
On April 12, an Illinois Department of Public Health (IDPH) grant-funded active tick surveillance program in Morgan County detected a specimen of the longhorned tick. The detection was thereafter confirmed by entomologists at the National Veterinary Services Laboratory. Further surveillance of the impacted area confirmed the presence of at least two more longhorned ticks on April 27, suggesting more may be in the area.
With its detection in Illinois, the longhorned tick has now been encountered in 20 states since a population was found to have successfully infested a sheep farm in New Jersey in 2017. It is believed to have migrated into the Midwestern United States from the East Coast by parasitizing bird populations.
An invasive species in the continental US, the longhorned tick is native to a large area of eastern Asia, including China, Japan, Korea, and parts of Russia, as well as Pacific Islands including New Zealand, Fiji, and particularly Hawai’i. Adult females are between 2-2.6mm in length with a light-brown or reddish body. Regional populations of longhorned tick are generally capable of either sexual or asexual reproduction; those populations in the US have exhibited asexual reproduction, with females independently capable of both laying and fertilizing up to 2,000 eggs, allowing an infestation to grow rapidly. No tick native to the US reproduces asexually.
Although it can carry a number of human diseases including Lyme disease, the CDC does not currently consider the H. longicornis a hazard to human health as members of this species display less interest in human hosts than native tick species do. This does not mean the tick is fully harmless to humans, as unfed females may still feed on humans and therefore expose them to disease.
Nevertheless, the largest threat posed by the longhorned tick is to cattle: unchecked infestations have been known to kill livestock by gradually draining entire animals of blood. Longhorned ticks also are prone to theileriosis, a group of diseases caused by parasitic protozoans which exclusively target cattle, causing further blood loss and eventual heart failure. These ticks will easily spread among farm animals such as cows, horses, sheep, pigs, chickens, dogs, and cats. They will also parasitize wild animals such as bears, deer, foxes, and hares.
The Illinois Departments of Agriculture, Public Health, and Natural Resources are coordinating to monitor the continuing spread of the longhorned tick. While government agencies continue to study the longhorned tick’s behavior and how it may impact humans, they recommend that people take the following precautions:
- Use Environmental Protection Agency (EPA)-registered insect repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), paramenthane-diol (PMD) or 2-undecanone. Always follow product instructions.
- Treat clothing and gear with products containing 0.5 percent permethrin. Permethrin can be used to treat boots, clothing and camping gear and remain protective through several washings. Alternatively, you can buy permethrin treated clothing and gear.
- Check your body and clothing for ticks upon return from potentially tick-infested areas, including your own backyard. Use a hand-held or full-length mirror to view all parts of your body. Place tick-infested clothes in a dryer on high heat for at least 10 minutes to kill ticks on dry clothing after you come indoors.
- Shower soon after being outdoors. Showering within two hours of coming indoors has been shown to reduce your risk of getting Lyme disease and may be effective in reducing the risk of other tickborne diseases. Showering may help wash off unattached ticks and is a good time to do a tick check.
- Talk to your veterinarian about tickborne diseases in your area and prevention products for your pets and livestock.
The State agencies instruct that if anyone believes they have identified H. longicornis on an animal, the tick should be placed in a jar of isopropyl alcohol, and the Department of Agriculture should be contacted at 217-782-4944.
