Mosquitoes don’t like smell of DEET, states U.S. study

William Atkins
Monday, 25 August 2008 20:03

Science - Health

The researchers studied Culex quinquefasciatus, a species of mosquito.

They discovered that this species of mosquito is sensitive to DEET through a neuron in its antennae that actually is able to smell chemicals such as DEET.

When the scientists applied DEET to “sugar stations” and then introduced C. quinquefasciatus mosquitos to the area, both the males and females avoided the area.

Leal and Syed conclude, “When applied to human skin, DEET altered the chemical profile of emanations by a “fixative” effect that may also contribute to repellency. However, the main mode of action is the direct detection of DEET as indicated by the evidence that mosquitoes are endowed with DEET-detecting ORNs [1-octen-3-ol] and corroborated by behavioral bioassays. In a sugar-feeding assay, both female and male mosquitoes avoided DEET. In addition, mosquitoes responding only to physical stimuli avoided DEET.”

After finding out the specific antennae neurons that detect DEET, Dr. Syed, stated, “I couldn't believe my eyes because it goes against conventional wisdom. So I repeated the experiment over and over until we discussed the findings in the lab.” [WebMD]

The surprising news is important to the world because of the spread of many diseases through mosquitoes.

Now that scientists know “why” DEET works to repel biting insects such as mosquitoes, they can work to better prevent the spread of insect-biting diseases such as West Nile Virus, malaria, Lyme disease, typhus fever, and St. Louis encephalitis.