The Asian longhorned tick (Haemaphysalis longicornis) has emerged as a growing concern for livestock producers in the United States, including the beef industry. First confirmed by the USDA in 2017, this invasive tick species may have arrived on animals, pets, or people as early as 2010. Since then, it has been detected in multiple U.S. states and continues to spread.
Originally native to East Asia, the tick is already established in countries like Australia and New Zealand, where it is known to cause economic losses in cattle herds. This tick can reproduce without mating, meaning that a single female can rapidly establish a population, laying up to 2,000 eggs at a time. The rapid reproduction rate, combined with a wide range of warm-blooded hosts—including cattle, horses, pets, and wildlife—makes this tick a formidable threat to livestock health and productivity.
What It Looks Like and Where It’s Found
Asian longhorned ticks are small and reddish-brown, often smaller than a sesame seed. Adult females, when engorged with blood, reach about the size of a pea. Infestations can be difficult to detect due to the tick’s small size and mobility.
They thrive in grassy, wooded environments and have now been identified in counties with high populations of cattle, sheep, and horses across the eastern and southern United States.
Impact on Cattle and Tick-Borne Diseases
Heavy infestations can stress animals, reduce growth, and lower production. In dairy cattle, infestations have been associated with up to a 25% drop in milk yield. In severe cases, excessive blood loss from multiple bites can lead to death.
Asian longhorned ticks are known to carry diseases such as Theileria orientalis Ikeda, which causes bovine theileriosis. Although not currently known to transmit Lyme disease in the U.S., laboratory testing has shown they can carry and potentially transmit Rickettsia rickettsii (Rocky Mountain Spotted Fever), Heartland virus, and Powassan virus.
Steps for Beef Producers
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Monitor livestock regularly for unusual tick infestations, particularly during the warmer months.
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Implement tick control programs in consultation with your veterinarian.
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Maintain pastures by trimming grasses, managing brush, and creating buffer zones between wooded areas and grazing land.
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Report unusual tick sightings to your local health or agriculture authorities for identification and monitoring.
Protecting Human and Animal Health
These ticks do not limit themselves to animals. Humans and pets can also be hosts, which raises public health concerns. After spending time outdoors, especially in grassy or wooded areas, check for ticks and remove them promptly using fine-tipped tweezers.
Reducing Habitat and Wildlife Risks
Wildlife can spread ticks to new areas. Keeping livestock areas well-maintained and creating physical barriers between grazing lands and forests can help reduce the risk of infestation.
As the Asian longhorned tick continues to expand its range, proactive management and education are critical for protecting U.S. cattle herds. Stay informed, stay vigilant, and work with your veterinarian or animal health official to implement an effective tick control strategy.
