Native Americans repelled insects with a noxious concoction of bear fat and pine tar. Thanks to modern chemistry, we now have our choice of repellents that are easy to use and won’t gag a maggot. But how effective are they?

To find out, we had Boy Scouts from Troop 15 (Westchester County, N.Y.) take four different repellents with them on a 10-day canoe trip in the Boundary Waters Canoe Area last summer to see how well modern bug dope could stand up to the area’s legendary hordes of flying pests. The results may surprise you.

Natrapel
$6 (5-oz. spray)
★ ★ ★ ★ ★
The Lowdown: Coming in at the head of the pack, this DEET-free product uses a proprietary formula that includes picaridin (a generic name for a completely unpronounceable chemical formula) that doesn’t cause adverse reactions and doesn’t smell like DEET. “I’m not saying it smelled good for a repellent,” said White. “I’m saying it smelled really good.”

Testers also liked the fact that Natrapel uses “all-natural” ingredients. The manufacturer claims eight hours of effectiveness for each application. The Scouts, however, found that reapplication was necessary every four to six hours in hot weather, because sweat diluted the repellent’s effectiveness.
Hits: “Worked well all day on mosquitoes and blackflies.” —Corrigliano
Misses: “Too greasy on skin.” —Sioufas

Ben’s 30% Wilderness Formula Pocket Size
$3 (1.25-oz. spray)
★ ★ ★ ★ ★
The Lowdown: Scoring just a single point less than Natrapel, Ben’s was cited for its convenient small size and an extraordinary ability to keep bugs away. The testers agreed to a man that it was the most effective repellent of all. Three said the DEET-based product lasted the longest, too. “It worked even when we got wet,” Corrigliano said. Gray thought it was “easy to use” but deducted points because he needed to “reapply it every few hours.” One drawback noted by White was the design of the bottle’s nozzle, which made it difficult to apply repellent “exactly where you want it.”
Hits: “The most water resistant.” —White
Misses: “Spray wouldn’t work when upside down.” —Gray

Off! Deep Woods Dry
$6 (4-oz. aerosol)
★ ★ ★ ★
The Lowdown: In another close finish, DEET-based Off! Deep Woods Dry came in just behind Ben’s. The product picked up points because of its ease of application (a wide spray area). But it lost points because testers noted that it was not as effective as the others. Sioufas praised the dry application, which left no greasy feeling on his skin. However, he said, “The product was not effective for long.” Testers also split votes over the portability of the packaging. Sioufas felt it “fit nicely inside backpacks and camping equipment,” but Corrigliano said the aerosol “is a lot bigger than the spray bottles and won’t fit into small pockets.”
Hits: “The aerosol covers a large area quickly.” —White
Misses: “Didn’t work well if you got wet.” —Corrigliano

Thermacell Mosquito Repellent Outdoor Lantern
$32 
★ ★ ★ ★
The Lowdown: ThermaCell products use allethrin-­impregnated pads that repel insects when heated by a butane burner. This version adds a camping lantern to the package. Testers said the product did a good job of repelling insects, and they liked the fact that they did not have to apply DEET. But they penalized it for its comparatively large size. “It’s not convenient for light backpacking and camping,” said Sioufas. White also said a big drawback was that “you had to stay on top of switching out the butane cartridges.” Gray, though, gave the unit a big thumbs-up, saying, “I did not get a single bite.”
Hits: “Easy to turn on and off.” —Sioufas
Misses: “Have to change strips too often.” —Corrigliano

From the August 2012 issue of Field & Stream magazine.

Photo by Meckes/Ottowa/Photo Researchers