July 3, 2012
Mosquitoes Follow Their Noses To Find Human Prey
redOrbit Staff & Wire Reports - Your Universe Online
With summer now in full swing, many of us will be entertaining with picnics and barbecues and socializing outside. Chances are, you´ll find some unwanted guests at your outdoor activities.
Mosquitoes seem to have a mysterious ability to locate human prey and Zainulabeuddin Syed, a mosquito biologist with the University of Notre Dame's Eck Institute for Global Health, has gone a long way towards figuring out how they do it. What he found is that it's all because of the way we smell.
Mosquitoes have an extraordinary sense of smell, reports Syed, and a big part of their brains are devoted to this sense. Only female mosquitoes feed on blood meals and they use the blood to produce eggs.
According to a prepared statement: "For example, Culex mosquitoes, which transmit West Nile and other life-threatening illnesses, are able to detect even minute concentrations of nonanal, a chemical substance given off by humans. They detect nonanal through receptor neurons on their antennae. Birds are the main hosts of mosquitoes and they also give off nonanal. Birds are the main source of the West Nile virus and when mosquitoes move on to feast on humans and other species, they transmit the virus to them."
An understanding of the olfactory behavior of mosquitoes that leads them to feed on humans can play an important role in creating more effective methods of mosquito and disease control.
Syed is also researching the part that plants play in mosquito activities. Despite our occasional feeling that we're surrounded by masses of hungry mosquitoes, they spend a relatively short amount of time feeding. They do, however, spend considerable time on plants taking the sugars that provide energy for those occasions when they do feed.
The Notre Dame researcher's lab is studying what plant smells the mosquitoes are attracted to. A deeper understanding of the role of the chemicals produced by plants and how mosquitoes select plants to obtain their energy sources can lead to better control and elimination strategies.
Syed points out that DEET is still an effective mosquito repellant and he was one of a team of researchers who revised the understanding of how it works. DEET was effective because it masked odors that attract mosquitoes. However, research by Syed and his colleagues showed that mosquitoes smell DEET directly and avoid it.
Better mosquito control techniques would result in greater comfort and convenience when we're outdoors. In many areas of the world, however, mosquito control is a matter of life and death. In Africa alone, malaria, one of the many diseases transmitted by mosquitoes, takes a human life, most frequently a child's, every 30 seconds. A better knowledge of the role smell plays in mosquito behavior can offer important evidence that may lead to new control strategies.