I came across an interesting article recently about mosquito repellants. If you live in, or are traveling to, an area where mosquitoes are common, this article is worth reading.

Generally, researchers have found that products containing DEET are the most effective, but there is a non-DEET product that was very effective as well – a product containing oil of lemon eucalyptus, or PMD, a natural oil extracted from the leaves and twigs of the lemon-scented gum eucalyptus plant. The researchers concluded that oil of lemon eucalyptus “was about as effective and as long lasting as products containing DEET.”

Here’s the original article.

A Guide To Mosquito Repellents, From DEET To … Gin And Tonic?

People do the darnedest things in hopes of avoiding mosquito bites. They burn cow dung, coconut shells or coffee. They drink gin and tonic. They eat bananas. They spray themselves with mouthwash or slather themselves in clove/alcohol solution. And they rub themselves with Bounce. “You know, those heavily perfumed sheets you put in your dryer,” says Dr. Immo Hansen, professor at the Institute of Applied Biosciences at New Mexico State University.

None of those techniques have been tested to see if they actually keep mosquitoes away. But that doesn’t stop people from trying them, according to a study that will be published this summer by Hansen and colleague, Stacey Rodriguez, lab manager at the Hansen Lab at NMSU, which studies ways to prevent mosquito-borne diseases. They and colleagues asked 5,000 people what they did to protect themselves against mosquitoes. Most used conventional mosquito repellents.

Then researchers asked about their traditional home remedies. That’s when the cow dung and dryer sheets came out. In interviews, Hansen and Rodriguez shared some of the responses they received. Their paper has been published in the peer-reviewed journal PeerJ.

Beyond folklore and traditional remedies, there are proven ways to protect against mosquitoes and the diseases they carry. NPR talked with researchers, many of whom spend lots of time in mosquito-infested jungles, marshes and tropical areas.

Which repellents work best to stop mosquitoes from biting?
Products containing DEET have been shown both safe and effective. DEET is shorthand for the chemical N,N-diethyl-meta-toluamide, the active ingredient in many insect repellents. A 2015 article in the Journal of Insect Science examined the effectiveness of various commercial insect sprays, and products containing DEET proved effective and relatively long lasting. Rodriguez and Hansen were authors of the 2015 study, and replicated the results in a 2017 article in the same journal.

DEET appeared on store shelves in 1957. There was some early concern about its safety — speculation that it was linked to neurological problems. But recent reviews, for example a study published in June 2014 in the journal Parasites and Vectors, says, “Animal testing, observational studies and intervention trials have found no evidence of severe adverse events associated with recommended DEET use.”

DEET isn’t the only weapon. Products containing the active ingredients picaridin and IR 3535 are as effective, says Dr. Dan Strickman, with the Global Health Program at the Bill and Melinda Gates Foundation (which is a funder of NPR) and author of Prevention of Bug Bites, Stings, and Disease.

Repellents with any of those active ingredients are recommended as safe and effective by the Centers for Disease Control and Prevention. They are widely available around the world.

Actually, Strickman gives the edge to picardin.

“Picaridin is a little more effective than DEET and seems to keep mosquitoes at a greater distance,” he says. When people use DEET, mosquitoes may land on them but not bite. When they use a product containing picaridin, mosquitoes are less likely to even land. Repellents with IR 3535 are slightly less effective, Strickman says, but they don’t have the strong smell of other products.

Then there is oil of lemon eucalyptus, or PMD, a natural oil extracted from the leaves and twigs of the lemon-scented gum eucalyptus plant, also recommended by the CDC. PMD is the ingredient in the oil that makes it repellent to insects. NMSU researchers found that a product containing oil of lemon eucalyptus was about as effective and as long lasting as products containing DEET. “For some people, there’s a stigma to using chemicals on their skin. They prefer a more natural product,” says Rodriguez.