what attracts or repels mosquitoes?
From an article in the Wall Street Journal:
"[...]Insects have very keen powers of smell that direct them to their targets. But for researchers trying to figure out what attracts or repels [mosquitoes], sorting through the 300 to 400 distinct chemical odors that the human body produces has proved daunting."
"Now scientists at Rothamsted Research in the U.K. have been making headway at understanding why some people can end up with dozens of bites after a backyard barbecue, while others remain unscathed. The researchers have identified a handful of the body's chemical odors-some of which may be related to stress-that are present in significantly larger concentrations in people that the bugs are happier to leave alone.
[...] 'Mosquitoes fly through an aerial soup of chemicals, but can home in on those that draw them to humans,' says James Logan, a researcher at Rothamsted[...]. But when the combination of human odors is wrong, he says, 'the mosquito fails to recognize this signal as a potential blood meal.'
The phenomenon that some people are more prone to mosquito bites than others is well documented. In the 1990s, chemist Ulrich Bernier, now at the U.S. Department of Agriculture's Agricultural Research Service, began looking for what he calls the "magic compounds" that attract mosquitoes. His research helped to show that mosquitoes are attracted to humans by blends of common chemicals such as carbon dioxide, released from the skin and by exhaling, and lactic acid, which is present on the skin, especially when we exercise. But none of the known attractant chemicals explained why mosquitoes preferred some people to others.
Rothamsted's Dr. Logan says the answer isn't to be found in attractant chemicals. He and colleagues observed that everyone produces chemicals that mosquitoes like, but those who are unattractive to mosquitoes produce more of certain chemicals that repel them."
The rest of the article outlines the experiments that were performed (I hope the people who stuck their arm in a tube full of mosquitoes were well-compensated for that task!), touches on the compounds that were isolated & their potential use & efficacy as repellents, & mentions some other research about mosquitoes.
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excerpts from "Finding Smells That Repel," by Shirley Wang
Wall Street Journal, 9/1/2009
"[...]Insects have very keen powers of smell that direct them to their targets. But for researchers trying to figure out what attracts or repels [mosquitoes], sorting through the 300 to 400 distinct chemical odors that the human body produces has proved daunting."
"Now scientists at Rothamsted Research in the U.K. have been making headway at understanding why some people can end up with dozens of bites after a backyard barbecue, while others remain unscathed. The researchers have identified a handful of the body's chemical odors-some of which may be related to stress-that are present in significantly larger concentrations in people that the bugs are happier to leave alone.
[...] 'Mosquitoes fly through an aerial soup of chemicals, but can home in on those that draw them to humans,' says James Logan, a researcher at Rothamsted[...]. But when the combination of human odors is wrong, he says, 'the mosquito fails to recognize this signal as a potential blood meal.'
The phenomenon that some people are more prone to mosquito bites than others is well documented. In the 1990s, chemist Ulrich Bernier, now at the U.S. Department of Agriculture's Agricultural Research Service, began looking for what he calls the "magic compounds" that attract mosquitoes. His research helped to show that mosquitoes are attracted to humans by blends of common chemicals such as carbon dioxide, released from the skin and by exhaling, and lactic acid, which is present on the skin, especially when we exercise. But none of the known attractant chemicals explained why mosquitoes preferred some people to others.
Rothamsted's Dr. Logan says the answer isn't to be found in attractant chemicals. He and colleagues observed that everyone produces chemicals that mosquitoes like, but those who are unattractive to mosquitoes produce more of certain chemicals that repel them."
The rest of the article outlines the experiments that were performed (I hope the people who stuck their arm in a tube full of mosquitoes were well-compensated for that task!), touches on the compounds that were isolated & their potential use & efficacy as repellents, & mentions some other research about mosquitoes.
__________
excerpts from "Finding Smells That Repel," by Shirley Wang
Wall Street Journal, 9/1/2009