It’s a bug’s life out there, but if you’d prefer to keep those critters off your skin, then you need to use some sort of repelling device.
The key is figuring out which ones work and which ones will simply bug you.
Citronella candles and other repellent devices like lanterns are intended to confuse mosquitoes so they can’t easily detect people – but some studies have shown that they are only effective for six to 10 feet, said Michael Waldvogel, director of the Raleigh-based Structural Pest Management Training & Research Facility.
Add a little breeze, and those lanterns and citronella candles will be useless.
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“Plus, some of these devices use chemicals for which there are warnings to avoid directly inhaling the vapors,” Waldvogel said.
A better choice could be a geraniol candle or diffuser. A 2009 study published in the Journal of Vector Ecology compared the degree of protection provided by citronella, linalool and geraniol in the form of candles or diffusers, and found that outdoors, citronella diffusers repelled female mosquitoes by 22 percent; linalool repelled them by 58 percent; and geraniol repelled females by 75 percent.
The key is the concentration level, said Mike Roe, an entomology professor at North Carolina State University. “Any chemical will repel an insect if the concentration is high enough,” Roe said.
He recommends using a spray rather than a candle, diffuser, wristband or patch – and spraying the repellent directly onto your skin or clothing.
“The wristbands or the patches that you can stick to your clothing will work within a few inches of where it’s installed, but it’s not going to protect your whole body,” he said.
Not all sprays are created equal, however.
While many people have turned to non-DEET products because of health-related warnings (the EPA reported seizures in one per 100 million users, and DEET is not recommended for infants younger than 2 months), the studies haven’t found non-DEET products to be very effective. A study published in the New England Journal of Medicine compared botanical insect repellents with DEET repellents and found that the DEET-based products provided complete protection for the longest duration. A formulation containing 24 percent DEET had a complete-protection time of 302 minutes, compared with a soybean-oil-based repellent, which protected against mosquito bites for an average of 95 minutes. All the other botanical repellents tested provided protection for less than 20 minutes.
Of course, there’s always the retro bug zapper – more formally called an electrical discharge insect control system – which attracts insects because of its light and zaps them when they arrive.
“Insects are attracted to light, so it’s going to attract all kinds of insects, good and bad,” Roe said. “But why would you want to indiscriminately kill all the insects in your yard? They’re not bad things – they’re part of our ecology.”
Roe suggested using the zapper in an enclosed porch, where the number of insects entering the space is lower – and you’re only killing the bugs that may potentially be entering your home.
The Environmental Protection Agency has an online tool to help consumers determine the repellent that’s right for them, and you can do a search by the amount of time you’ll need to be protected, the type of bug you’ll need protection from and the active ingredient you desire. It also lets you search by company name, and the products are all EPA-registered repellents. Check out the EPA website for more information.
One key point, however, said Waldvogel:
These are repellents, so they don’t actually kill the mosquitoes or other biting pests.
“I like to use the analogy that if you’re driving the highway and you come across a detour, presumably you just don’t sit there,” Waldvogel said. “So particularly with mosquitoes, make the effort to eliminate the breeding sources of the mosquitoes where possible – very often in your own backyard or your neighbor’s backyard.”