Q. My Scout Troop took a four-day backpacking trip in the Sierra Nevada mountains. The mosquitoes were the biggest problem on the trip. I used several different bug sprays, and only one of them worked. But the one that worked only worked for about 15 minutes. What type of bug spray (preferably natural) could I use that would keep the mosquitoes away for at least an hour? Also, I’ve heard that there is clothing that keeps bugs away. How effective is this clothing?
— Mosquito-Mauled Mel, Irvine, Calif.
A. I feel your pain, Mel. Mosquitoes really can cramp your style around camp. The good news: There are repellants that work. The bad news: Most aren’t made from natural ingredients.
You’ll hear and see all kinds of advertisements boasting natural repellants and how well they work. They might be somewhat effective for a short while, but if you’re serious about avoiding bug bites, DEET-based repellants are the most effective. The stuff really works (it’s what the Army uses), but it’s also the most toxic for our bodies — it smells very strong, will melt some plastics, and don’t even think about getting it in your eyes!
Repellants are available in different concentrations of DEET, from 4.75-percent to 100-percent. Typically, the higher the concentration of the active ingredient, the longer the protection it’ll provide. For instance, a spray with 4.75-percent DEET would last about an hour or so while repellent with 23.8-percent DEET would be effective for almost five hours.
Do some testing of your own to figure out which is the lowest percentage of DEET repellant that still keeps the bugs away for you. Folks who are very susceptible to bug bites seem to feel like 25 percent DEET is the lowest concentration they can get away with using.
You might also try repellants that use Picaridin, it’s a newer (but not natural) DEET alternative that smells less strong and is perhaps a bit less toxic. But you guessed it: it’s still not as effective as DEET.
Your best bet is to wear light-colored long sleeve shirts and pant that are treated with an insecticide called Permethrin. This is safer because it’s not directly applied to your skin — and it works (the Army uses this too). You can get your own bottle of the stuff, like Sawyer Permethrin Clothing Insect Repellant ($9; sawyer.com), and spray it on your own clothes — have your parents help! Or you can buy new clothing treated with Insect Shield (www.insectshield.com). I was skeptical of the Insect Shield clothing but I’ve tested it in some very buggy areas and I can say it does indeed work.
Still, the only way to be 100 percent free of bug bites is to wear Permethrin-treated clothing and spray DEET on your exposed skin.