Featured Research

from universities, journals, and other organizations

Follow the odor and CO2: Flight patterns reveal how mosquitoes find hosts to transmit deadly diseases

Date:
October 5, 2011
Source:
University of California - Riverside
Summary:
Experiments performed by entomologists to study how female Aedes aegypti -- mosquitoes that transmit yellow fever and dengue -- respond to plumes of carbon dioxide and human odor demonstrate that puffs of exhaled carbon dioxide first attract these mosquitoes, which then proceed to follow a broad skin odor plume, eventually landing on a human host. Results from the study could clue scientists on how odors can be used in traps for intercepting host-seeking mosquitoes.

An Aedes aegypti mosquito prepares to bite a human.
Credit: Image courtesy of USDA.

The carbon dioxide we exhale and the odors our skins emanate serve as crucial cues to female mosquitoes on the hunt for human hosts to bite and spread diseases such as malaria, dengue and yellow fever.

Two entomologists at the University of California, Riverside have now performed experiments to study how female Aedes aegypti -- mosquitoes that transmit yellow fever and dengue -- respond to plumes of carbon dioxide and human odor.

The researchers report in the Oct. 15 issue of the Journal of Experimental Biology that puffs of exhaled carbon dioxide first attract these mosquitoes, which then proceed to follow a broad skin odor plume, eventually landing on a human host.

The results from the study by Ring Cardé, a distinguished professor of entomology at the University of California, Riverside, and Teun Dekker, formerly a graduate student in Cardé's lab and now an assistant professor at the Swedish University of Agricultural Research, could clue scientists on how odors can be used in traps for intercepting and capturing host-seeking mosquitoes.

Yellow fever is a viral disease that causes 30,000 deaths worldwide each year. Dengue, another viral disease, infects 50 to 100 million people worldwide a year, leading to half a million hospitalizations, and 12,500,000 deaths.

In the lab, the researchers released female yellow fever mosquitoes into a wind tunnel they built, and filmed their flight paths. They found that:

  • Mosquitoes head upwind only briefly when they encounter just a whiff of carbon dioxide but proceed continuously upwind when the carbon dioxide plume is turbulent, fluctuating in concentration and mimicking the presence of a live host.
  • Mosquitoes' orientation to human skin odor, in contrast, is optimal when the plume of skin odor is broad and unvarying in its intensity, as would occur when a mosquito closes in on a potential host.

"Carbon dioxide induces a faster and more direct upwind orientation than skin odor," said Cardé, who holds the Alfred M. Boyce Chair in Entomology. "Our experiments show that the response of yellow fever mosquitoes to skin odor requires an exposure longer than that of carbon dioxide to induce upwind flight."

Dekker and Cardé also report that the dynamics -- response time, duration and speed -- of carbon dioxide-induced upwind surging were very similar across a wide range of carbon dioxide concentrations, from 100 to 0.05 percent (barely above atmospheric levels).

"The mosquitoes' carbon dioxide receptors allow the insects to respond almost instantly to even the slightest amount of the gas," Cardé said. "Carbon dioxide alone attracts these mosquitoes and does not require assistance from other odors. Skin odors, however, become important when the mosquito is near the host, selecting biting sites. Further, the mosquitoes' sensitivity to skin odors increases 5- to 25-fold after 'priming' with a whiff of carbon dioxide."

The research project was supported by grants to Cardé from the University of California Systemwide Mosquito Research Program and the Office of Naval Research -- DARPA Plume Tracing Program; to Dekker, the research paper's first author, from Insect Chemical Ecology, Ethology and Evolution (ICE3) Linnaeus and the Swedish Research Council FORMAS.


Story Source:

The above story is based on materials provided by University of California - Riverside. Note: Materials may be edited for content and length.


Journal Reference:

  1. T. Dekker, R. T. Carde. Moment-to-moment flight manoeuvres of the female yellow fever mosquito (Aedes aegypti L.) in response to plumes of carbon dioxide and human skin odour. Journal of Experimental Biology, 2011; 214 (20): 3480 DOI: 10.1242/jeb.055186

Cite This Page:

University of California - Riverside. "Follow the odor and CO2: Flight patterns reveal how mosquitoes find hosts to transmit deadly diseases." ScienceDaily. ScienceDaily, 5 October 2011. <www.sciencedaily.com/releases/2011/09/110930153054.htm>.
University of California - Riverside. (2011, October 5). Follow the odor and CO2: Flight patterns reveal how mosquitoes find hosts to transmit deadly diseases. ScienceDaily. Retrieved September 15, 2014 from www.sciencedaily.com/releases/2011/09/110930153054.htm
University of California - Riverside. "Follow the odor and CO2: Flight patterns reveal how mosquitoes find hosts to transmit deadly diseases." ScienceDaily. www.sciencedaily.com/releases/2011/09/110930153054.htm (accessed September 15, 2014).

Share This



More Plants & Animals News

Monday, September 15, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) — New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) — A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
'Magic Mushrooms' Could Help Smokers Quit

'Magic Mushrooms' Could Help Smokers Quit

Newsy (Sep. 11, 2014) — In a small study, researchers found that the majority of long-time smokers quit after taking psilocybin pills and undergoing therapy sessions. Video provided by Newsy
Powered by NewsLook.com
Spinosaurus Could Be First Semi-Aquatic Dinosaur

Spinosaurus Could Be First Semi-Aquatic Dinosaur

Newsy (Sep. 11, 2014) — New research has shown that the Spinosaurus, the largest carnivorous dinosaur, might have been just as well suited for life in the water as on land. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins