California scientists are reporting a pair of victories in the epic struggle between man and mosquito.
A team at the University of California, Riverside, appears to have finally figured out how bugs detect the insect repellent known as DEET. And the team used its discovery to identify several chemical compounds that promise to be safer and cheaper than DEET, according to the report in the journal Nature.
Three of the new repellents are already approved by the Food and Drug Administration as food additives. “One of them is present in plum,” says Anandasankar Ray, of the University of California, Riverside, who led the study. "The other is present in orange and jasmine oil. Some of them are present in grapes. And, as you can imagine, they smell really nice."
The new repellents, if they pan out, could make a huge difference in developing countries where mosquito-borne diseases such as malaria and dengue fever are common, says Craig Montell, a researcher at the University of California, Santa Barbara, who is not connected to the new research.
Though effective, DEET is too expensive for many people in developing countries, Ray. Also, he says, consumers have to be careful how they use the repellent. It can dissolve plastics, including nylon.
Even so, DEET has been the gold-standard bug repellent since the U.S. Army developed it in the 1940s, Ray says, despite many efforts to find something better. “The main reason why scientists haven’t been able to improve upon DEET is because they just didn’t know how DEET is detected by the insects,” he says.
Now, it appears, they do know, thanks to experiments with some genetically modified fruit flies in Ray’s lab. These custom-made flies have special nerve cells in their antennae that glow a fluorescent green when they react to DEET, Ray says.
The illustration shows four DEET-like mosquito repellents discovered by the team at the University of California, Riverside. Three of them are safe to eat. Courtesy of Pinky Kai/University of California, Riverside
Flowers and fruits to the rescue in the never ending fight of man versus mosquito! ~AR