My life as a mosquito magnet

How come some people attract swarms of mosquitos while others –often nearby- rarely get bitten?  How come you get singled out and not the guy or gal next to you at the backyard BBQ?

Mosquitos primary senses are sight and smell, says Jonathan Day, a professor of medical entomology at the University of Florida in Vero Beach. Lab studies suggest that 20 percent of people are high attractor types, he says.

Mosquito’s vision is highly acute, especially later in the afternoon, and their first mode of search for humans is through vision, explains Day. People dressed in dark colours — black, navy blue, red — stand out and movement is another cue.  While standing completely still may not always be possible, unless of your course you are a robot street performer, wearing light colours can make you less conspicuous.

Once the mosquito locates a promising visual target, she (and it’s always “she” — only the ladies bite) then picks up on smell. The main attractor is your rate of carbon dioxide production with every exhale you take.  Larger people and pregnant women have higher rates of carbon dioxide production.  Your rate of carbon dioxide production also increases during exercise.  While you may be able to outrun them in a golf cart, it’s a big red flag for mosquitoes that says “meal time”.   Although carbon dioxide is the primary attractant, other secondary smells coming from your skin or breath mark you as a good landing spot.

Lactic acid (given off while exercising), acetone (a chemical released in your breath), and estradiol (a breakdown product of estrogen) can all be released at varying concentrations and lure in mosquitoes, says Day. Your body temperature, or warmth, can also make a difference. Mosquitoes may also flock to pregnant women because of their extra body heat.

Researchers are still uncertain behind a mosquito’s preference for certain people, says Joseph Conlon, a medical entomologist and the technical advisor to the American Mosquito Control Association due to more than 350 compounds isolated from odors produced by human skin.   Human odor and genetics are not the only factors, studies of twins have revealed it’s more complicated than that, suggests Conlon.

Conlon said that recent thoughts are it may not be what mosquitoes find attractive but what is repellent.  It could be that individuals who get less bites produce chemicals on their skin that make them more repellant and cover up smells that mosquitoes find attractive.

Mosquitoes don’t feed off you, since they feed off plant nectar, Conlon explains. Females use your blood to obtain a necessary protein for egg development.  I will try and forget this next bit of advice: Mosquitoes are more attracted to people after they drink a 12-ounce beer.

Here are more fun facts about mosquitoes and bites provided by our experts:

• Eating bananas will not attract mosquitoes and taking vitamin B-12 will not repel them; these are old wives’ tales.
• Some mosquito species are leg and ankle biters; they cue into the stinky smell of bacteria on your feet.
• Other species prefer the head, neck and arms perhaps because of the warmth, smells emitted by your skin, and closeness to carbon dioxide released by your mouth.
• The size of a mosquito bite welt has nothing to do with the amount of blood taken and everything to do with how your immune system responds to the saliva introduced by the mosquito into your skin.
• The more times you get bitten by a particular species of mosquito, the less most people react to that species over time. The bad news? There’s more than 3,000 species worldwide.