Photo (cc) by John Tann
I love summer, but unfortunately, the advent of summer in northern Montana brings a very unwelcome guest: mosquitoes – and lots of them.
The area where I live, with its irrigated croplands, ponds and pools of sitting water, is mosquito heaven. In fact, Montana is one of the 10 worst states in the U.S. for mosquitoes. Any outdoor activity, including walking to the end of my long driveway to check the mail, involves spritzing my body with a DEET mosquito repellent, unless I want to be covered in itchy bites.
I don’t like using strong chemicals like DEET on my skin, but I do like its effectiveness in warding off mosquitoes. I use more natural repellents on my children, but I have to reapply them often, and they’re not nearly as effective.
But I could soon have a new, favorite mosquito repellent, and it’s all natural.
New research described in an American Chemical Society press release has confirmed that sweetgrass, a plant used in Native American traditional medicine, is effective in keeping biting insects, particularly mosquitos, at bay. The research was presented this week at a meeting of the American Chemical Society in Boston.
Sweetgrass is native to northern climates, including Montana.
“It gives off a sweet aroma that repels mosquitoes,” said chemist Charles Cantrell, who has worked with colleagues at the USDA’s Natural Products Utilization Research Unit at the University of Mississippi to test plants used in traditional therapies.
Cantrell steam-distilled oil from sweetgrass and used the compound alongside DEET to test mosquitoes’ avoidance. In one test, sweetgrass oil matched the repellent potency of DEET.
DEET is the gold standard for deterring biting insects, but its potential for environmental damage and toxicity to humans has been a concern, according to the Smithsonian. Cantrell said that DEET is not only effective, but it lasts for a long time.
“You see that the market is being flooded with natural products, essential-oil-based insect repellents,” Cantrell said. “There are some that work, but there are a lot of them that may only work for 20 or 30 minutes. What we’re ideally looking for is something natural and nontoxic that’s just as effective as DEET, that will work as an effective repellent for 10 or 12 hours like DEET.”
When broken down into its chemical components, sweetgrass has two chemicals – phytol and coumarin – that appear to repel mosquitoes.
Coumarin is an ingredient in some mosquito repellents, and the potential repelling activity of phytol has been documented in scientific literature.
Still, Cantrell said he’s happy that “we were able to find constituents that are known to act as insect repellents in a folk remedy, and now we understand that there’s a real scientific basis to this folklore.”
Cantrell plans to continue studying the long-term effectiveness of sweetgrass to see if it’s up to par with repellents like DEET.
It’s also important to note that not only are mosquito bites itchy and annoying, they’re potentially dangerous. Mosquitoes can carry diseases including West Nile virus, St. Louis encephalitis, malaria and others.
I would love to have an all-natural alternative to chemical DEET that is not only effective, but lasts longer than 20 minutes.
What do you think of using sweetgrass as a mosquito repellent? Share your comments below or on our Facebook page.