Scientists Develop Genetic Approaches to Combat Disease-Carrying Ticks
A collaborative effort between the Texas A&M Department of Entomology and the U.S. Department of Agriculture (USDA) has led to the development of genetic tools that could help manage ticks responsible for spreading diseases.
Jason Tidwell is pursuing his doctorate while working for the USDA-ARS Cattle Fever Tick Research Unit based in Edinburg. (Photo courtesy)
A recent study authored by Tidwell, who is both a part-time graduate student in the Texas A&M College of Agricultural and Life Sciences and a full-time microbiologist at the USDA’s Cattle Fever Tick Research Unit, lays groundwork for innovative control strategies against cattle fever ticks — the carriers of pathogens responsible for bovine babesiosis, historically referred to as Texas cattle fever.
Tidwell focuses primarily on genetic research concerning arthropods, particularly cattle fever ticks. His publication reports on fundamental research that has pinpointed genetic markers associated with sex determination in the tick species Rhipicephalus microplus, one of two invasive cattle fever tick species native to northern Mexico and a constant threat of re-establishing in the U.S.
Collaborative Research Could Enhance Tick Management
Kimberly Lohmeyer, Ph.D., director at the Knipling-Bushland U.S. Livestock Insects Research Laboratory in Kerrville, highlighted that Tidwell’s research exemplifies how uncovering previously unknown biological aspects of a pest can lead to new pest management solutions.
Lohmeyer noted that Tidwell became engaged by the prospect of employing genetic control methods against significant pests, and his findings now pave the way for innovative strategies against ticks that carry diseases.
“This study lays the groundwork for future advancements in protecting U.S. livestock from cattle fever ticks,” she commented. “It solves a fundamental biological puzzle related to these ticks and significantly moves us closer to novel eradication tools.”
According to Pete Teel, Ph.D., a research scientist at Texas A&M AgriLife in the Department of Entomology and one of Tidwell’s mentors, his identification of sex determination mechanisms is vital for understanding how to genetically control tick reproduction.
“This research establishes a basis for potential genetic pest control strategies that have been successfully applied to other arthropods, such as the primary screwworm and several types of mosquitoes,” Teel explained.
An image of a female Rhipicephalus (Boophilus) microplus, also known as the Southern cattle fever tick. This study by the USDA-Texas A&M Department of Entomology revealed the chromosomes responsible for determining ticks’ sex. Such a discovery could lead to innovative control strategies against these and other disease-carrying ticks. (Photo by Sam Craft/Texas A&M AgriLife)
Research Establishes Potential Tactics Against Ticks
The Cattle Fever Tick Eradication Program is a collaborative initiative between the USDA Animal and Plant Health Inspection Service Veterinary Services and the Texas Animal Health Commission aimed at preventing the re-establishment of the two species of cattle fever ticks in the U.S. Since its inception in 1906, the program has successfully eliminated the ticks across all 13 southern states and California, except for a permanent quarantine zone in South Texas.
“These ticks are the sole carriers of pathogens resulting in bovine babesiosis. Thus, by eliminating the ticks, the risk of disease is also eliminated,” Teel stated.
Currently, there are no licensed vaccines against babesia nor any therapeutic options available for the disease. The eradication program has relied heavily on chemical control through acaricides, which target ticks and mites. The introduction of genetic control methods would present a pioneering approach, particularly as cattle fever ticks are increasingly developing resistance to these conventional treatments.
“One potential strategy is to genetically alter the environmental sex ratios of ticks to hinder reproduction and reduce their populations,” Tidwell elaborated.
This genetic strategy has already shown effectiveness in managing Aedes aegypti mosquitoes, which are known for spreading diseases like West Nile virus, dengue fever, yellow fever, and Zika. Thus, Tidwell’s findings could inspire similar control techniques for other tick-borne illnesses, such as Lyme disease in humans.
Aaron Tarone, Ph.D., an AgriLife Research scientist and professor in the Department of Entomology, as Tidwell’s co-advisor, emphasized that any new control method should be sustainable from logistical, environmental, and economic standpoints. However, he concurred that this research heralds exciting possibilities for future advancements.
“The next phase will involve constructing the genomes of local tick populations from Texas and Mexico to study their genetic differences,” Tarone mentioned. “The emerging capabilities in genomics and the related technology offer countless avenues for addressing vectors that pose serious risks to both human and animal health.”
