Does lemongrass really repel ticks? This expert decided to find out

As Nova Scotians long for warmer weather this spring, the province's large tick population is doing the same.

Blacklegged ticks, or deer ticks, are often found around Nova Scotia, hiding in long grass and attaching to a host without notice.

Bites from these insects can result in Lyme and other diseases in humans and animals.

But researchers at Acadia University's chemistry department are working to determine if lemongrass essential oil works as a natural tick repellent.

CBC Radio's Maritime Noon spoke with Dr. Nicolette Faraone with Acadia's chemistry department about their latest research and what Nova Scotians should know ahead of tick season. 

This conversation has been edited for length and clarity.

What did you observe when ticks came in contact with lemongrass essential oil?

Ticks get repelled. They don't like the smell of lemongrass. They wave their front legs, try to smell the repellent and they back off. So, it's a good sign.

How did you test this? 

We did a type of test in our lab and we assessed their repellent effect. We had sticks that we put in a plate and they were surrounded by the lemongrass and we checked if they were crossing the area treated with the lemongrass. 

If they cross, it means that they were not repelled, but most of the time they stay in the confined area, indicating that they were repelled.

LISTEN | Does lemongrass essential oil work as a tick repellent?

Maritime Noon52:45On the phone-in: Paul Arnold from Acadia University answers questions about composting. And off the top, we hear how lemongrass is a deterrent to ticks. And parents in Moncton complain about a school bus driver.

On the phone-in: Paul Arnold who teaches at the Ivan Curry School of Engineering at Acadia University answers listeners' questions about composting. And off the top of the show, we speak with Nicoletta Faraone from the Chemistry Department at Acadia University about a new study that shows that ticks are repelled by lemongrass. And some parents in Moncton, NB, complain about a school bus driver.

How does the lemongrass affect the ticks? 

They kind of stop moving and considering the ticks are almost totally blind, the moment that you block the ability of them to smell, which is the way they orient themselves in their environment,  they don't know where to go. That's why they are inhibited and they get stuck.

Why does lemongrass seem to work? What is it in lemongrass that the ticks don't like?

Lemongrass essential oil, and all the essential oils, are made by a mix of different components and each one may have different properties and different effects. So what we did in our study was also analyze the different components of lemongrass, which are very smelly compounds. 

And we found that citral geraniol, geranyl are the main chemicals that are responsible for the repellent activity that we've seen in ticks. And this compound is also commonly found in other types of essential oils like lemon essential oil, citrus essential oils and so on.

Some people in the past have not been comfortable spraying on the kinds of insect repellents that contain chemicals such as DEET. So lemongrass, the essential oil, is a natural product. Is it safer to use?

I would say since I'm a chemist, I know that everything is basically a chemical and if it's not used properly at the right concentration, it can be dangerous. Now essential oils, which are natural products, are safer than synthetic-made components and compounds because they are biodegradable. 

They degrade faster in the environment and they have less of an impact on humans and the environment. So, I would say they are safer, but they need to be used wisely. 

What would you say is the significance of your findings when you put it in the context of what currently is on the market and what we see as a seemingly growing tick population in the region?

What we found in our study is that essential oils and specifically in this case, lemongrass, induce a certain inhibitory activity. So they mask the other smells around, making the tick unable to detect a potential host.

Now, there's so much more to do in terms of research and understanding the mechanism of other detection. But this is quite promising because it gives us a better understanding of how ticks can find us.

Since the tick population is growing in Canada, especially in the northern territories, because of climate change and because of changes in the climate in general, we need to be more aware and be more conscious that ticks are out there. 

What direction do you plan to go with your future research?

The idea is to try to better understand the mechanism of the repellent and the attraction on ticks because this information can give us the right tool to properly design a good repellent product.

In fact, I've been working for many years with a Nova Scotia company, AtlanTick, and we have been working on developing new products that are essential oil-based that can be applied on the skin or on fabric. So the idea is not just knowing the chemical ecology of ticks, but by using this information to properly develop products that can give us protection and can avoid the spread of Lyme disease.