STUDY: Which Mosquito Repellants Work Best?

JOURNAL: University of Florida's Vero Beach Research Center

AUTHORS: Dr. Jonathan Day

ABSTRACT: On one side of the annual battle is everybody's least-favorite summer visitor: the mosquito. On the other is Dr. Jonathan Day, one of the nation's foremost medical entomologists.

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COMMENTARY: Day has spent years at the University of Florida's Vero Beach Research Center studying how to keep the mosquitoes off your neck. "People want to be out on their deck enjoying the evening — enjoying the outdoors — and mosquitoes make it virtually impossible for that to happen," Day said.

So how well do the lotions and electronics designed to do battle with mosquitoes really work.

A test was set up called a mosquito cage test. Each "trial" uses 80 hungry females, since the female mosquitoes are the only ones that bite. Brave volunteers stick their arms into the cages, with their bare skin protected only by repellents. Mosquitoes are ferocious insects. In one minute almost every mosquito in this cage will bite an untreated arm.

Mosquito Contro Plus: The first product tested was the "Mosquito Contro Plus" by Lentek. The $20 device looks like a watch, and emits a tiny "buzzz" sound. The company says the sound irritates mosquitoes, and keeps them away.

One volunteer, Anne, tried it first, and the mosquitoes went right for her arm. The mosquitoes landed around the watch, one just landed right on the watch. When another volunteer, Greg, tried it, he fared even worse, and was left with mosquito bites covering his arm. "This isn't slowing them down — isn't stopping them," Day said. "We don't have to do much more." Day's bottom line on the Contro-Plus? "They are a waste of the consumers' money," Day said. Lentek, the company that markets the product, disagreed with Dr. Day.

Off! Botanicals Lotion: Next, they tried out the Off! Botanicals lotion. This type of repellent uses a derivative of eucalyptus oil to shoo away the bugs. The volunteers had good results, half an hour after applying the lotion. But how long would it last? Both the volunteers still had good protection at the 1 hour and 45 minute mark. After 2½ hours, Hilda was still getting some protection, but Nazar wasn’t so lucky. He was bitten 11 times. But Day says the Off! Botanicals did a great job by lasting as long as it did. "The eucalyptus really looks good," Day said.

Off! Deep Woods and the Cutter Skinsations: Like many products on the market, these two contain the chemical repellent N, N-diethyl-meta-toluamide, better known as "DEET". For 50 years, DEET has been considered the gold standard of repellents. Sure enough, both products offered great protection for our volunteers. Walter, who was using the Cutter Skinsations, did get one bite on his finger, but the difference was visible when he puts his other unprotected arm in with the very same batch of mosquitoes. They basically fed on his arm. Cutter Skinsations, which contains 7 percent DEET, gave the volunteers about one hour of protection. The Off! Deep Woods, which contains 30 percent DEET, lasted more than two hours, and according to Day, can last up to six.

Parents should know, however, that while most experts say DEET products are safe, the American Academy of Pediatrics recommends children only use products with less than 10 percent DEET.

My advice is always, if the mosquitoes are unbearable on your deck in the evening-go inside. Using chemicals and trying to fight Mother Nature sometimes just isn’t worth it. If you are going to be in the woods the use of repellents becomes more important due to the risk of Lymes disease at least here in the northeast. Try to not touch your mouth with your hands and when you get home was the chemicals off. Remember to spray around your ankles and shoes.