Using Wind to Repel Mosquitoes

December 24, 2002

Mosquitoes can spread diseases such as malaria, encephalitis, yellow fever, and West Nile virus. Scientists are always looking for ways to protect people from these diseases.

A chemical mosquito repellent, such as DEET, is one established way to avoid mosquito bites. In fighting mosquito bites, it is helpful to know what these insects like and dislike. For example, some mosquitoes favor temperatures between 37 and 40oC and humidities between 70 and 80%. Mosquitoes are also attracted to carbon dioxide and lactic acid that humans release when we breathe and sweat.

To study new ways to control mosquitoes, researchers at the Department of Entomology at Michigan State University experimented with two things that mosquitoes don't like: DEET and wind. In fact, mosquitoes seem to avoid places with wind speeds that approach their own flying speeds (0.4 to 1.6 meters/sec; 0.9 to 3.6 miles/hour).

The researchers set up their experiment in the woods of Michigan. They applied 90% DEET to an air filter that was connected to a large fan. A test subject was placed 1.6 meters downwind from the fan. The wind speed at this distance away from the fan was 0.6 meter/sec. One researcher, covered in protective clothing, stood by the test subject and counted the number of times mosquitoes oriented to, landed on and probed the test subject. As soon as a mosquito probed the test subject by attempting to feed, the researcher collected the mosquito in a vial for later identification.

When the fan was turned on and blew DEET into the air, the number of orienting, landing and probing mosquitoes was less than when the fan was turned off. If no DEET was added to the filter, the fan still reduced the number of mosquitoes compared to conditions when the fan was left off. However, the best results were obtained in windy conditions with DEET.

Why does wind work to repel mosquitoes? Wind may interfere with the mosquito's ability to fly and thus be unable to move to a food source. If a mosquito can't fly, it can't find you. Wind may also disperse carbon dioxide and lactic acid given off by a person. If a mosquito can't smell you, it can't find you. The combination of DEET and wind provides an extra punch to the mosquito olfactory sense -- giving humans another weapon in the fight against pesky mosquito bites.

Hear It!
DEET Olfactory

Did you know?
  • The full chemical name for DEET is N,N-diethyl-3-methylbenzamide.
  • DEET was developed by the US Department of Agriculture and was patented by the US Army in 1946.
  • Only female mosquitoes bite.
  • There are more than 2500 species of mosquitoes in the world. The U.S. is home to 200 species; Florida alone is home to 77 species. (Source: The American Mosquito Control Association)
  • Mosquitoes transmit disease to more than 700,000,000 people each year. (Source: Fradin, M.S., Mosquitoes and mosquito repellents: a clinician's guide, Annals of Internal Medicine, 128:931-940, 1998)
  • Sweat, carbon dioxide and lactic acid attract mosquitoes.
  • The nickname for the state of New Jersey is "The Mosquito State." (Source: State nicknames)

References and further information:

  1. Hoffmann, E.J. and Miller, J.R. Reduction of mosquito (Diptera: Culicidae) attacks on a human subject by combination of wind and vapor-phase DEET repellent. J. Med. Entomology, 39:935-938, 2002.

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