If You Wash With This Kind of Soap, You Could Be Attracting Mosquitoes
Can't stop itching from bug bites? It may be time to swap out your soap, according to Virginia Tech researchers.
You’ve tried everything: Bug spray, citronella candles, bug repellent bracelets. You’ve planted mosquito-repelling plants, like rosemary, basil and marigolds. Yet despite how many different hacks you’ve tried, nothing seems to ward off the mosquitoes that attack when the sun sets below the horizon.
After so many attempts at trying to get rid of those pesky bugs, just hoping you can finally enjoy a night outside in peace, you may start wondering if there’s something else that’s making you a mosquito magnet. Do mosquitoes really gravitate toward certain blood types? Or could it really be as simple as how you smell?
Turns out, according to a recent study from researchers in the College of Agriculture and Life Sciences at Virginia Tech, your smell can actually attract or repel those summertime pests—particularly the scent of your soap. These researchers found that soaps with the scent of plants and florals can unfortunately attract mosquitoes. That soothing rose body wash or that lavender-scented bar soap you love? They could be to blame for all of those bug bites you find yourself scratching at the end of the day.
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What the study says
Chloé Lahondère, Ph.D., a study author and assistant professor of biochemistry at Virginia Tech who focuses on research regarding Mechanisms of Thermal Adaption in Insects, explains that the purpose of this study was to determine which chemicals and scents humans add to their original body odour would attract mosquitoes.
“We expected that adding these chemicals to our body odour would affect their attraction, in one way or another,” Lahondere says. “But what was surprising in our results was the importance of the interaction between the specific soap chemicals and the body odour of each specific individual in determining whether a person would become more or less attractive to mosquitoes after applying soap to their skin. In other words, we were surprised to see that some soaps, but not others, would increase the attractiveness of some people.”
“Three out of four soaps we tested in this preliminary study increased mosquito attraction for our volunteers,” says Clément Vinauger, Ph.D., another author of the study who also works as an assistant professor of biochemistry at Virginia Tech and specializes in Molecular Genetics of Host-Seeking Behaviour in Insects. “These soaps have in common that they are rich in terpenes, a class of chemicals typically produced by plants and found in the scent of flowers and fruits. Among them, we found allyl heptanoate, which is naturally found in the scent of tropical fruits and used in perfumery to imitate the pineapple scent, was often associated with increased mosquito attraction.”
In particular, floral scents tend to attract mosquitoes given that these bugs use plant-emitted volatiles to find these types of plants to obtain the sugars from the nectar. With soap that smells like these attractive florals, it makes sense that mosquitos would be attracted to similar-smelling skin.
However, Vinauger does point out that it is the combination of the scent and a person’s natural body odour that can attract bugs, so certain soaps may work for some and not others. For those who find themselves constantly attacked by mosquitoes, it may be a trial and error process to find the right soap that works for you.
Look for particular chemicals in your soap
The results of the study not only point out specific scents that may attract mosquitoes, but also points out how personal care products contain certain chemicals that can increase mosquito activity due to these scents. Lahondere says this information could be critical for the hygiene industry.
“We should definitely be looking more carefully at the composition of the personal care products we use,” Lahondere continues. “As stated in the study, the same soap used by different people can have different effects on mosquito behaviour. However, it might be better to stay away from personal care products that contain high levels of chemicals that mosquitoes are known to be attracted to, like linalool.”
Linalool is a popular floral chemical found in over 200 different flowers and plants—like lavender and citrus fruits—and is used in 60% to 80% of perfumed hygienic products such as soaps, lotions, detergents and shampoos. Previous studies have actually made a connection between linalool repelling female mosquitoes, sometimes more so than citronella, which is a scent commonly used in candles and bug repellents. However, with this study indicating otherwise, products that use this chemical may not have the repelling effect we once believed.
“We can provide critical information to the industry to develop new personal care products that do not contain mosquito attractants—or if they do, highlighting that a specific ratio of these compounds should be used so the soap or perfume does not increase mosquito attraction (and thus biting),” she says.
The best soap fragrance for fighting mosquitoes
If floral-scented soaps aren’t helping with fighting off mosquitoes, then what will? According to previous research, it may be wise to swap out your go-to soap product with something that is coconut scented or based.
“Multiple publications—including ours—have shown that coconut-derived chemicals tend to have a repellent effect on blood-feeding insects,” says Lahondere. “To our knowledge, the underlying mechanisms remain unclear.”
One 2018 study from the U.S. Department of Agriculture even found coconut oil to be a better bug-repellent than DEET—a chemical used in popular bug-repellent products. The study found the coconut oil fatty acids had a strong repellency and long-lasting effectiveness (95% effective compared to DEET, which was only at 50% during the study) to ward off pesky bugs including mosquitoes, ticks, biting flies and bed bugs.
While more research needs to be done, if you had to choose a scented soap to use this summer, a natural coconut-based soap (with fewer chemicals) would give you more of a fighting chance against irksome mosquito bites compared to your usual floral-scented body wash.
Next, find out the most harmful ingredients in your beauty products.
