Essential Repellent: What You Need to Know to Survive the Battle of the Bug

Stay bug-free this summer with tips and tricks from Mountaineers Board Member and alpine scrambling volunteer Steve McClure. Learn about the different types of bug deterrent and put together a bug-defense plan for a happy summer.
Steve McClure Steve McClure
Mountaineers Board Member & Bug Repellent Aficionado
July 15, 2017
Essential Repellent: What You Need to Know to Survive the Battle of the Bug
Mosquito by Tom Dani.
This article originally appeared in the Washington Trails member magazine and on the WTA website. See the original story here.

The West Coast’s winter was wet and soggy. The forecast for the spring and summer is lingering snowpack, muddy trails … and bugs. Lots of bugs!

Hikers are a hearty bunch, occasionally discouraged but rarely deterred by mosquitoes, ticks, or swarms of biting flies—the pull of the trails is stronger than the annoyance. When the bugs become intolerable, the historical defense has been chemical warfare, with DEET as the primary weapon. For many hikers, the cure is worse than the disease, and they keep the nasty, plastic-melting DEET in its holster as long as possible.

But ignoring the bugs until they’re intolerable can ruin an otherwise enjoyable trip. And beyond putting a damper on the general mood, bug bites can have longer-lasting effects. Those with sensitive skin may have welts that last for weeks. Your kids might refuse to enjoy your next outdoor adventure. And, beyond those annoyances, bugs carry disease. While the risk from bugs is higher in other parts of the world—malaria and dengue, for instance—insects in the United States can also transmit diseases such as Lyme disease, Rocky Mountain spotted fever, West Nile or Zika

If you’re not fond of DEET, don’t worry. It’s not your only option to fend off the bugs. Sure, it’s proven to work and is a common go-to, but if you’d rather avoid it, there are effective alternatives. By combining chemical repellents with a system of clothing, you can enjoy the trails without getting carried away by the biting insects.

Beyond DEET: A Better Defense Against the coming spring attack of the arthropods


A multilayered strategy is the best approach, says Rick Hemmerling, vice president of business development at clothing technology company Insect Shield LLC. Rick lives in Seattle, where Insect Shield’s marketing and sales are based.

“For decades, it was all about DEET. We now have clothing available with a polymer permethrin coating that will help keep most bugs at bay for the life of the garment which, we consider to be 70 launderings,” he says.

Permethrin is an insecticide originally found in chrysanthemum flowers and then synthesized in the lab. Insect Shield was the pioneer in bringing permethrin to clothing, creating the first EPA-registered insect-repellent clothing. They developed a polymer permethrin clothing treatment and shepherded it through the EPA safety and efficacy procedures.

“The process was long and arduous, but eight years of safety and efficacy testing proved that this stuff works, and no cautions, warnings or age restrictions are required on the garments,” Rick says.

The U.S. military has been issuing kits to soldiers to treat their own uniforms with permethrin since 1991, and in 2010, the Army began issuing uniforms that were factorytreated with permethrin.
A little careful preparation can save your hike if the bugs are bag. Photo by Julie Mahieu.


Nasty as it is, there’s no doubt that DEET is effective against mosquitoes and ticks. It is, however, wimpy against flies. DEET, a byproduct of World War II, will melt plastic. Apply with caution around critical gear such as glasses, watch faces, and especially climbing rope and webbing. Exactly how DEET works is still debated. However, if you end up with even a tiny amount on your tongue, the world’s most horrible taste will make you understand why bugs steer clear.

While DEET is available in concentrations of up to 100 percent, a 30 percent solution is safer and sufficient, and the time-release formulas will last a long time. DEET can be effective up to 12 hours for ticks and mosquitoes.


Also known as Icaridin, KBR 3023, Bayrepel, and Saltidin, this repellent is starting to replace DEET on many wilderness trips. Available in Europe since 2001 and in the United States since 2005, this nonplastic-melting, nongreasy, odorless chemical is nearly as effective as DEET against mosquitoes and ticks and more effective against flies.

Since picaridin will not hurt plastics, the repellent can be applied to tents, packs and other gear. Picaridin can be effective up to 12 hours for ticks and mosquitoes.


Also new to the scene as a DEET alternative, OLE (also known as PMD) was originally a naturally derived chemical similar to menthol. Approved in 2005 with the natural-sounding name “Oil of Lemon Eucalyptus,” the OLE molecule is synthetically manufactured.

OLE is effective against mosquitoes, ticks and flies but must be applied twice as frequently as DEET or picaridin, as it offers six hours of protection rather than 12. It is easily the smelliest of the four effective repellents but its attractiveness to hornets, bees and bears is not well studied. Fragrance attracts bears so the author, at least, will not use OLE in bear country.

5: IR 3535

Another chemical, IR 3535, has been used in Europe since the 1970s but has just started to be used in the United States This molecule was synthesized to replicate a naturally occurring amino acid.

What about Avon Skin So Soft and all the rest? 

If they worked, they’d be EPA registered for claims past two hours. Citronella, cedar oil, treated wristbands, garlic, vitamin B-12, ultrasonic devices and a panoply of natural ingredients are all equally ineffective. The one exception is reformulated Skin So Soft. The marketing power of the myth about this product was so strong that Avon has created a new line called Skin So Soft Bug Guard to which they have added picaridin or IR 3535, which is proven effective.

WT_may+jun_bugs2 copy.jpg

What About Kids?

Many parents are uncomfortable coating their kids with a chemical that can melt plastic, even if that chemical has been declared safe by the EPA.

DEET has a way of migrating into a child’s mouth and eyes, a real problem when washing facilities aren’t nearby. Not to mention, it can be hard to apply bug spray to wiggly kids. And if they get ahold of the DEET, some of your plastic items might end up with a few tiny fingerprints.

That said, for kids you can generally, follow the same bug defense strategy as with adults, with extra care. If using DEET as the repellent, use extreme caution on face and hands. Better yet, use picaridin or OLE.

If you are using repellent and sunscreen (this applies to adults too), apply the sunscreen first and allow it to dry. Then apply the repellent.

When your child is scratching an itchy bite and asks you to “make it stop” having some anti-itch cream or drops available will save the day.

But remember, especially with kids, some days the bugs win the battle and it’s best to retreat to a trusty tent with full bug screens.

Battle Plan

Now that you’re well-armed for the battle of the bug, here’s how to put this together in a bug-defense plan:

  • Campsite choice: For the evening, select the right campsite. Try for a spot with low environmental impact and a breeze, and keep your distance from marshy mosquito breeding areas as well as horse camps.
  • Clothing choice: Wear clothing that is heavy enough to thwart a mosquito’s proboscis or a fl y’s biting jaw—thin or tight-fitting clothing might not do the job. When the bugs are winning the battle, consider adding a bug net over your head.
  • Treated clothing: Next in the arsenal is clothing with factory-applied or home-applied permethrin.
  • Chemical repellents: The final element, chemical insect repellents, are compatible with permethrin-treated clothing. You can use the repellent of your choice, but consider picaridin rather than DEET. To use insect repellent, begin by applying it to clothing. Pay special attention to hats, scarves, wristbands and especially socks—mosquitoes have an uncanny ability to target ankles. Lastly, apply repellent to exposed skin. Use extreme caution with the face, perhaps first spraying a small cloth for application.

About The Author

Steve McClure is active with The Mountaineers as a member of the board, co-chair of the Intense Basic Alpine Climbing course, and an instructor for alpine scrambling and navigation. Steve is on the team that is writing the 9th edition of Mountaineering: The Freedom of the Hills.

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Chris Finley
Chris Finley says:
Aug 01, 2017 02:07 PM

Thanks Steve, nice information.
We have been having good luck with Tea Tree Oil as an anti-itching treatment.

Brian Young
Brian Young says:
Aug 01, 2017 09:50 PM

Great article Steve!! An alternative to Deet is exciting. For reference, everyone at the Citadel covers themselves in Avon's Skin So Soft for Friday afternoon dress parades. Works great on the Charleston mosquitos - but likely just for a limited duration. It was humorous to see 2k+ guys buying Avon from their mom's friends.