My wife and I joined some friends for a barbecue in their backyard. The guests were lively and the space was lovely - grassy and open but shady and surrounded by lots of shrubs and trees. In other words, it was perfect for mosquitoes.
But our friends had come up with a solution.
On a low table, they set up a small electric fan, perhaps 12 inches high, that swept back and forth, sending a gentle breeze across the grassy area where people were sitting.
That was it. No citronella candles, no bug zappers, no DEET, nothing expensive or high-tech. Yet amazingly, it worked. As far as I could tell, no mosquitoes flew into the vicinity of the simulated wind; nobody was bitten.
Outsmarting bugs with a fan is endorsed by the American Mosquito Control Association, a nonprofit group based in Mount Laurel, N.J., that publishes a journal bearing its name.
“Mosquitoes are relatively weak fliers,” it says on its website, “so placing a large fan on your deck can provide a low tech solution.” The group says mosquitoes fly slowly - from roughly 1 to 1.5 mph, depending on the species.
Scientists have identified another factor. The breeze from a fan disperses the human emanations that allow female mosquitoes to zero in on us. Humans exhale lots of carbon dioxide - the most widely recognized of the many likely mosquito attractants, including body heat and odors. When a female mosquito senses the invisible gas, she typically flies a zigzag path within the plume to track down its source.
In a wetland swarming with mosquitoes, entomologists from Michigan State University did an experiment that demonstrated not only the attractive power of a carbon dioxide trap but the effectiveness of plume disruption.
“Fan- generated wind strongly reduced the mosquito catches,” the scientists wrote in The Journal of Medical Entomology. “We recommend that fan-generated wind should be pursued as a practical means of protecting humans or pets from mosquitoes in the backyard setting.”
ActiveStyle, Pages 28 on 07/29/2013