Researchers trying to develop a better mosquito spray

Even if mosquitoes didn’t carry deadly diseases, the annoyance alone would keep us trying to spray them away. DEET has been the spray of choice for 50 years, but it’s not perfect.

Ulrich Bernier, University of Florida-Gainesville, said, “They tend to melt plastics, it tends to also have a sticky feel on the skin and some people find the odor of DEET offensive. So we’re trying to come up with some different chemicals that might solve some of these problems as well as last much longer than DEET does.”

Ulrich Bernier and colleagues at USDA and the University of Florida started with a USDA database of more than 40,000 chemicals that had been tested against mosquitoes since the 1940’s.

Using sophisticated software that compared the chemicals’ structures with effectiveness, they were able to predict new molecules that might be more effective, and safe.

“We’re going back and looking at these chemicals in a new way using modeling approaches based upon their structure to try to devise and figure out what makes a good repellent,” said Bernier.

As they wrote in the “Proceedings of the National Academy of Sciences,” the team then created those new compounds in the lab, and compared them to DEET. They tested the compounds on cloth because their safety on skin is not yet known.

Bernier said, “In looking at about 34 different compounds, we found about a third of them that lasted at least as long as DEET and some of them, up to three times as long as DEET.”

While the research so far predicts good repellency and safety, the researchers say thorough safety tests must be done before the new repellents can be tested on people.

The researchers now plan to use this new approach to develop better insecticides.