As much as we all enjoyed that blast of early spring weather this March, it also heralded in one of Nova Scotia's less welcomed experiences: ticks. It turns out that the eight-legged crawler is just as much of a fan of temperatures above 4°C as we are.
But there's also some excellent news emerging this spring: In a groundbreaking study led by Acadia University, researchers have gained a better understanding of how lemongrass essential oil significantly impairs the ability of blacklegged ticks to detect humans. The findings, published in Current Research in Insect Science by Dr. Nicoletta Faraone (Chemistry), Dr. Luis Anholeto (Chemistry), Dr. Kirk Hillier (Biology), and Masters graduate Kayla Gaudet ('22), could pave the way for more effective, natural tick repellents, offering a safer alternative to synthetic chemicals like DEET.
The science in a snapshot
Blacklegged ticks (Ixodes scapularis), notorious for carrying Lyme disease and other pathogens that can cause debilitating diseases in humans, rely heavily on their olfactory systems to locate hosts. In fact, this species of ticks doesn't have eyes and almost exclusively depends on their sense of smell to find nourishment.
The study found that exposure to lemongrass essential oil disrupts the ticks' ability to detect human scents, effectively "blinding" them to potential hosts. The research conducted at Acadia, which included ticks confirmed to be carrying Lyme disease, revealed that lemongrass oil offers a dual benefit in addition to masking attractive scents (like the chemicals humans emit, such as carbon dioxide and butyric acid), the oil has a repelling effect which makes us "unappetizing".
Dr. Nicoletta Faraone, an associate professor in Acadia's chemistry department and head of the Faraone Lab, took the lead on the research. She explains the significance of the results generated by her team and how they could point to practical solutions people could use in their everyday lives.
"Ticks exposed to lemongrass oil are less likely to crawl on you, and even if they're brave enough to do so, they're far less likely to bite," says Dr. Faraone. "The tick will likely be repelled or become so disoriented that it drops off."
One of the most exciting aspects of this research is the potential for lemongrass oil to serve as a natural alternative to DEET, the most commonly used synthetic repellent. While DEET is effective, it has been linked to environmental and health concerns, including toxicity to aquatic life and potential skin irritation in humans.
"Lemongrass oil is not only effective but also environmentally friendly," says Dr. Faraone. "It's a win-win for those looking to protect themselves from ticks without the drawbacks of synthetic chemicals."
Applying the research to real life
For the average person, this finding could mean safer, more natural options for tick protection. And a bonus? Lemongrass essential oil has been found to repel mosquitos, too.
But before you run out and start drenching everyone and everything in the natural oil, Dr. Faraone stresses that her study took place in a controlled lab environment.
"Diluted or formulated versions of lemongrass essential oil are largely considered safe and beneficial for most people," said the chemist. "But even those products should be tested on a small patch of skin first to make sure they don't cause any irritations or reactions." Some essential oils can be toxic to family pets, including cats and dogs, so veterinarians should be consulted before any repellant is used around animals.
AtlanTick® repellent: A Made-in-Canada success story
Acadia University's tick research has already had a tangible impact on our community's well-being through its collaboration with AtlanTick Repellent Products, a Nova Scotia-based company that provides safe and effective natural tick and insect protection for families and pets. It's a relationship that's been cultivated by Acadia's Office of Industry and Community Engagement in its effort to support local businesses and contribute to Acadia's service mission by generating financial, economic, academic, and societal benefits for our local and regional community. Dr. Faraone has been involved since 2017 to further develop and optimize AtlanTick's natural repellent formulations, including helping to ensure the products meet Health Canada's rigorous safety and efficacy standards. Dr. Faraone and her team are continuing to explore new products and expanded applications and formulations of the AtlanTick brand, especially in light of their ongoing research findings.
Leading tick research and training tomorrow's innovators
These efforts are just a few pieces of a bigger picture that is putting Acadia at the forefront of tick research. It's work that's gained increased importance as tick populations and instances of Lyme disease rise in the Maritimes.
Dr. Faraone and her team have begun to explore the chemosensory systems of ticks in greater depth, including those of other tick species found in the area. Through funding provided by the NSERC Discovery Grant, NSERC Alliance and Mitacs Accelerate grants and matched by AtlanTick, Dr. Faraone and her talented post-doc, Dr. Luis Anholeto, are now investigating environmental conditions like temperature and humidity on tick responses in order to gauge the possible effects brought about by a warming climate. This ongoing research could lead to even more effective tick control strategies in the future.
The work doesn't stop there. Another project with community impact is eTick, a national online platform where the public can submit tick pictures for identification. It serves a double-duty of providing a valuable community service while also sourcing scientists with information on tick distribution and tick species across Canada. Since 2020, 8,640 valid submissions of ticks have been done in Nova Scotia. Supporting the Atlantic provinces, eTick is helmed by Acadia's Dr. Kirk Hillier (Biology), Dr. Laura Ferguson (Biology), and Dr. Dave Shutler (Biology). They're joined by paid student researchers or "Tick Techs" who are getting applicable, career-boosting experience even at the undergrad level.
In fact, students have been involved all along the way, including in the major research stories coming out of the university. Professors have prioritized experiential opportunities, ranging from fieldwork (collecting ticks), to lab access (conducting experiments), to interpretation (data analysis and reporting).
"At Acadia, students aren't just learning," says Dr. Faraone. "They're gaining hands-on experience while contributing to research that has real-world applications and impact."
