NMSU graduate student develops a new way to test tick repellents Lorem ipsum dolor sit amet, consectetur adipiscing elit.

A longer warm season us allowing ticks to stick around later in the year. These pests are among the most common transmitters of disease to humans and animals. A New Mexico State University biology student developed a new way to test the effectiveness of tick repellents to improve repellent products and individual protection. The results were published in a peer-reviewed journal where she tested four well-known repellents.

Hailey Luker found her passion for research on vectors of human diseases such as ticks and mosquitoes as an undergraduate during a class taught by Immo Hansen, NMSU professor in the Department of Biology. She joined Hansen’s lab as a technician in 2019 and is now a graduate student studying cell and organismal biology.

“Hailey is an exceptional student,” said Hansen. “She spent many hours optimizing her tick assay until it worked flawlessly. The trick was to identify the right species of ticks and put them in a position where they try to attach to a host.”

Ticks can gain access to human hosts by attaching to clothing. Repellents sprayed onto fabric are often used to deter them. Luker researched a new method to test how well repellents work at deterring ticks. She tested well-known products like DEET to determine their effectiveness at repelling ticks.

“I started to work with a carousel toy that was intended to be used to test tick repellents many years ago, however no protocols up to that point had any success with testing ticks in the setup,” Luker said. “After testing, observing, brainstorming and changing different variables, I developed a protocol that produced consistent data and called it the Tick Carousel Assay.”

Luker, who earned her Bachelor of Science in biology and conservation ecology, used fabric sprayed with the most common active ingredients in repellents to measure tick engagements to the fabric over time.

Using the carousel, the fabric was brushed against ticks located on an artificial grass patch. Luker measured tick engagements to the fabric over time. 

“The Tick Carousel Assay can test the repellent properties of novel products that are not yet released to the public and compare them with repellents that are currently on the market,” Luker said.

Luker, who conducted her research as an undergraduate, published the results on the Tick Carousel Assay in her first peer-reviewed article in “PeerJ,” an online open access journal.

Using the Amblyomma americanum, or lone star tick, Luker tested four of the most common insect repellents that have the active ingredients DEET, Picaridin, IR3535 or oil of lemon eucalyptus.

Repellency of these products was tested at three time points: immediately after application, after three hours and after six hours post application to the fabric.

“The results of this study were that each of the four products that are readily available for purchase provided protection against ticks for up to six hours,” Luker said. “The results also indicated that after six hours, oil of lemon eucalyptus repelled ticks more than the other active ingredients.”

The study also demonstrated the Tick Carousel Assay provides an affordable, repeatable and standardized way to compare and test repellent efficacy on treated fabrics.

“This first-hand research experience as an undergraduate was critical to my confidence as a scientist and to my interest in research as I began pursuing graduate school,” Luker said.

“Without this experience, I would feel less sure of what I am capable of and would be starting from scratch. Now that I have first-authored my own published, peer-reviewed scientific research paper and understand more about the research world, I feel well prepared for the challenges ahead of me as I continue graduate school.”

Luker plans to focus her research as a graduate student on molecular biology but will continue to study tick control and disease prevention.

 

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