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Mosquito Repellent

April 7, 2008

The insect repellent DEET doesn’t repel mosquitoes so much as confuse them.

Transcript

BOB HIRSHON (host):
A mask against mosquitoes…. I’m Bob Hirshon and this is Science Update.

The chemical DEET has been used for decades as an insect repellant, but no one really knew how it worked. Do insects think it smells bad, or does it deter them in some other way? Now, scientists at The Rockefeller University have found the answer. Molecular neurobiologist Leslie Vosshall says that DEET blocks an odor receptor responsible for an insect’s sense of smell.

LESLIE VOSSHALL (The Rockefeller University):
The DEET just jams the olfactory system and makes the insects blind to odors. So it’s not really a repellant but more of a cloaking device or something to make humans invisible to insects.

HIRSHON:
Vosshall says DEET doesn’t stop insects from detecting the carbon dioxide that attracts them to us, but it confuses them enough so they won’t see a DEET-covered human being as food. This could lead to the development of safer mosquito repellents in the future. I’m Bob Hirshon for AAAS, the science society.