On today’s Cow-Calf Corner, Mark Z. Johnson, Oklahoma State University Extension Beef Cattle Breeding Specialist, talks about Asian Longhorned Ticks.
Asian longhorned ticks (Haemaphysalis longicornis) are invasive pests that pose a serious threat to cattle in the United States. They can form large infestations on one animal and spread diseases that impact both animals and humans alike. This species of tick is native to East Asia, including China, Japan, the Russian Far East and Korea. Asian longhorned ticks (ALHT) are not normally found in the western hemisphere but have become a concern since 2017, when public health officials in New Jersey reported the first detection of the ALHT outside of a U.S. port of entry inspection site. Since that time, the ALHT has spread to 19 states including: Arkansas, Connecticut, Delaware, Georgia, Indiana, Kentucky, Maryland, Massachusetts, Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia, and West Virginia.
The ALHT has the unique ability to reproduce quickly and in large numbers. Unlike other tick species, the ALHT is parthenogenetic, meaning an individual female they can lay eggs without mating, essentially cloning herself to create the next generation. This allows few individual female ALHT to establish large populations very quickly. This is one reason the ALHT is a successful invader of new geographic regions. In addition, they have been found to infest a wide range of hosts, including mammals, birds, and reptiles, which further increases their potential impact. As well, there are no known natural predators to the ALHT in the United States, which also contributes to their ability to spread into new areas.
One of the main concerns with the ALHT is their ability to transmit diseases. While there have been no reports of ALHT transmitting disease to humans in the United States, they have been found to be infected with several pathogens. Asian longhorned ticks in the United States successfully transmitted Theileria orientalis Ikeda to cattle in the laboratory. This pathogen has also been detected in field-collected ALHT. Clinical signs of theileriosis are similar to anaplasmosis in cattle and include anemia, jaundice, and weakness. Therefore, there is a potential risk for disease transmission if these ticks are not properly managed.
While the risk of disease transmission from ALHT to humans in the United States is currently low, their potential to establish populations and transmit diseases makes them a concern. Proper management and control measures, such as tick checks, pesticide treatments, and removal of potential tick habitats, can help reduce the risk of exposure to these ticks and the diseases they may carry. It is important to be aware of the potential risks and take precautions to protect yourself and your cattle. The ALHT may be introduced to new areas through the movement of host animals, contaminated clothing or equipment, or other means of transport. Once introduced, these ticks can quickly establish populations and become a nuisance. Methods of tick control are addressed in the third USDA reference below.
References:
https://www.aphis.usda.gov/livestock-poultry-disease/cattle/ticks/asian-longhorned
https://www.aphis.usda.gov/sites/default/files/theileria-orientalis-ikeda-notice.pdf
https://www.aphis.usda.gov/sites/default/files/monitoring-h-longicornis-plan-final-january-2024.pdf
Dr. Justin Talley has information about the Asian Longhorned tick and Dr. Barry Whitworth explains how it impacts livestock from SunUpTV from June 6, 2020. https://www.youtube.com/watch?v=qgjGZvt5gao&t=99s
