By Mark Rackay, Montrose County Sheriff’s Posse
My wife and I were taking a stroll along the canal bank near our home. It was early evening, and the mosquitoes were out in full attack mode. After several minutes of slapping, and defoliating nearby shrubbery with colorful, albeit mature-audience-only expressions, I noticed they were not bothering her.
I accused her of using some bug spray before we left and forgetting to include me in the spray down, but she insisted she did not use the spray. It got me thinking about why some people have a natural defense against the bloodsuckers, while other people seem to be an attractant.
My fame for attracting hungry mosquitoes is still spoken of throughout the Florida Everglades in hushed, reverent whispers. I never figured out what it was; maybe just halitosis or the heartbreak of psoriasis, but if you were to line up 50 people and turn loose one hungry mosquito, I would give very good odds that he would pick yours truly as the host for his evening meal.
Mosquitoes are no laughing matter. The U.S. Centers for Disease Control and Prevention call mosquitoes the “world’s deadliest animal.” It’s a weighty moniker for an insect that weighs 2.5 milligrams (although I can’t envision someone putting one on a scale) but it is well deserved because vector-borne diseases transmitted by mosquitoes cause over 700,000 deaths worldwide every year. Montrose and Delta counties are no exception, with our own fatal cases of West Nile every year.
Turns out, there is much evidence to support the theory that some people are bitten by these pests more than others. Studies show that around 20% of people are particularly irresistible to these winged vampires. Some of these reasons you can control, others you can’t.
Mosquitoes find certain blood types more desirable than others. Research indicates that some species prefer Type O blood, as in the Asian tiger mosquito, while the Marsh mosquito prefers AB blood. Before you ask how a mosquito knows, 80 percent of people produce a secretion that signals what blood type they are, and the mosquitoes hone in on their preferred flavor.
These vampires are attracted to carbon dioxide and can detect it from great distances. The more you exhale, the more attractive you become. Larger people, like my 200 plus never-you-mind body, exhale more and are more likely to receive bug bites. Mosquitoes can see humans from up to 50 feet away, and a larger person is easier to spot.
Female mosquitoes are attracted to body heat and are attracted to heated people even when other sources of heat are around. If you exercise outside, or have a higher body heat temperature than most, you will draw the beggars.
Another attractant for them is human sweat. I am one who is acclimated very well and that means I will sweat whenever I am heated up. Human sweat emits lactic acid, ammonia, and other compounds, all of which are attractants to the mosquito. My wife, like most women, does not sweat, she perspires, and like most women, she does not perspire.
Some research has shown that bacteria on a person’s skin can be an attractant to bug bites. Mosquitoes prefer people with more carboxylic acids on their skin. One study found these fatty acids were highly concentrated on the skin of those who were most attractive to mosquitoes. This explains why many bites occur on feet and ankles, because these areas are especially ripe for bacterial growth.
A study in Africa found that twice as many mosquitoes gravitated toward pregnant people compared to non-pregnant people. This can be associated with the carbon dioxide attraction because women in later stages of pregnancy exhale a 20% greater volume of breath compared to non-pregnant women. Also, pregnant women tend to have a slightly warmer body temperature, also serving as an attractant.
Some studies indicate you may want to watch your alcohol intake when you are outside during peak mosquito times. Researchers found that significantly more mosquitoes landed on people who had consumed beer compared to people who had consumed water. Reasons for this are unclear and more research needs to be conducted, lest we wind up with a swarm of drunken mosquitoes to ruin our barbecue.
One thing that attracts mosquitoes, that you can control, is the color of your clothing. Mosquitoes use their eyes to spot victims and will head to darker colors, such as dark green and black clothing. Colors like whiter, khaki, and beige seem to be avoided, perhaps because they can’t see them as well.
There is hope on the horizon. The U.S. Department of Defense is funding a program to develop repellents that can be applied once to the skin and remain active for several months. The project, called ReVector, has identified specific carboxylic acids that might be powerful attractors, and are engineering bacteria-based skin creams that are specifically targeted to break down those compounds.
I am a person who is of larger size, sweats profusely while recreating outdoors, and enjoys an adult beverage while barbequing dinner in the evening. My only choice is to spray myself regularly with copious amounts of bug spray anytime I head outside in the morning or evening when these pests are most active. If I can just remember to spray down before I leave the house, I will have it made.
Mark Rackay is a columnist for the Montrose Daily Press, Delta County Independent, and several other newspapers, as well as a feature writer for several saltwater fishing magazines. He is an avid hunter and world class saltwater angler, who travels around the world in search of adventure and serves as a director and public information officer for the Montrose County Sheriff’s Posse. Personal email is elkhunter77@icloud.com.
