A single female Asian longhorned tick can produce 4 million disease-carrying ticks in one generational life cycle.
The Asian longhorned tick (Haemaphysalis longicornis) or ALT for short, poses a growing threat to cattle producers in the United States. Originating from eastern China, Japan, the Russian Far East, and Korea, it has spread to Australia, and New Zealand.
This invasive pest was first identified in the US in 2017 but is suspected to have arrived here as early as 2010. The Asian longhorned tick is now spreading in the U.S., increasing the risk of Theileria orientalis Ikeda infections in cattle.
Tick Characteristics
A unique aspect of the Asian longhorned tick is its ability to reproduce without a male (called parthenogenesis), potentially producing millions of ticks by the second generation.
The Asian longhorned tick is a three-host tick, meaning it attaches and feeds on three different hosts throughout its life cycle, complicating control efforts.
“This three-host tick attaches to a new host at each molting phase of its development, feeding and then dropping off to molt before finding another host. This can include a variety of mammals, making control challenging,” explains Dr. M. Wayne Ayers, Elanco beef technical consultant.
In comparison, a single-host tick has one host animal through its three molds before becoming an egg-laying adult. Both single-host and three-host female ticks die after egg laying.
Disease Risk
The primary concern of Asian longhorned tick infestations is Theileria orientalis Ikeda resulting in the development of bovine theileriosis disease, which causes severe anemia in cattle, affecting all ages from calves to mature cows.
This contrasts with anaplasmosis, another tick-borne cattle disease, which typically impacts older cattle the most. Symptoms to watch for include anemia with or without jaundice, weight loss, inappetence, decreased milk production, abortions, and death. There are no approved treatments for theileriosis disease.
“Even a single tick can transmit disease, and with cattle bearing numerous ticks, the risk is high if they aren’t swiftly removed,” notes Dr. Ayers. “Once a cow is infected, there is concern that further spread can occur through blood by needles, biting flies, and other tick species, all potentially serving as mechanical vectors.”
What to do if an infestation is suspected
- Collect suspect ticks preserve them in alcohol.
- Deliver samples to your veterinarian, state veterinarian, or Extension office for identification.
- Submit aborted fetuses and blood samples from affected cows for testing.
- Once one has a herd affected by Theileriosis, use ranch-raised heifers for replacements. Avoid the risk of introducing unexposed animals without natural immunity.
“Diagnostics are important to being aware of where the Asian longhorned tick is currently located and where they may be moving,” Ayers says.
Management Strategies
- Pre-treat animals arriving at your farm with approved insecticides labeled for ticks.
- Quarantine new arrivals in a dirt-floored corral for several days.
- Ensure thorough spray coverage, focusing on hidden areas where ticks embed.
- Minimize tick habitats by maintaining clean pastures and reducing brush.
- Utilize backrubs, oilers, and automatic sprayers in pastures so cattle periodically self-apply insecticide treatment.
Currently, there are no insecticides labeled explicitly for the Asian longhorned tick nor related disease in the United States.
Understanding and managing the Asian longhorned tick is crucial for beef producers to protect their herds. Stay informed and proactive to mitigate the risks associated with this invasive species.
Please review the current USDA policy thoroughly to ensure understanding and applicability to your operations. To learn more about controlling ticks on your operation, visit Elanco.com or reach out to your local Elanco representative.
