How Mosquitoes Choose a Target

With summer coming, most Americans can gear up for bug bite central. While many of us are buying bug repellant, mosquito resistant candles and other means of warding off summer pests, some people aren't worried about the summer bug season at all. Why is this? Nearly everyone has known someone who claims bugs like mosquitoes just don't bite them. Is this an actual fact? Or are these individual simply not reacting to the bites that most people react to, and thus aren't noticing that they're getting bit?

The truth is that some people just get bitten more than others. More annoyingly, it has a lot to do with our blood types. According to Knight (2007), scientists have identified "several proteins found in mosquitoes' antennae and heads that latch on to chemical markers, or odorants, emitted from our skin." This means that mosquitoes are attracted to odors and chemical omitted by certain body types, and thus these body types are more likely to get bitten. Knight (2007) goes on to state that "carbon dioxide in the breath, pregnancy, body temperature, alcohol, and odorant markers" are sought out by mosquitoes according to their protein markers, and that these markers are "based on blood type."

One study conducted on why mosquitoes target specific people over others found that individuals with type O blood were more likely to be bitten than those with other blood types (I.e. AB, A, B) (Knight, 2007). Before you jump to the conclusion that blood type is preferred by mosquitos, it should be explained that type O blood was found to secrete more chemical markers than other blood types, which caused the mosquitoes to be attracted to them. So, it isn't that type O blood is preferred, but that this blood type tends to attract blood-sucking pests (including flies) because it emits chemical markers more readily than other blood types.

So, what if you're not an O blood type but still seem to be a mosquito magnet? Well, as mentioned earlier, blood type isn't the only factor. In fact, people with blood types that don't emit the proteins that attract mosquitoes and other blood-sucking pests can also be targets for other reasons. It is for this reason that pregnant women may also be a higher target. According to Knight (2007), "mothers-to-be exhale 21 percent more carbon dioxide" and are "on average 1.26 degrees Fahrenheit warmer around the belly than their non-pregnant counterparts." This warmer body temperature and high carbon dioxide emission rate is a great way for mosquitoes to tell where you are. Bodies with these traits have a different body chemistry than those without, so they are more susceptible to bug bites. This is also why alcohol consumption can increase your chances of being bitten. Just as in pregnant women, when drinking, your body temperature tends to rise. This is a biological marker for mosquitoes and flies, which triggers their biological instinct to bite. If that fact doesn't encourage you to buy mosquito repellant candles for your next beach or lakeside barbecue, I don't know what will!

The Wall Street Journal (2009) published a study that found that mosquito repellents worked to throw mosquitoes off of body's chemical secretions that might previously have attracted their attention. This fact may prove especially important for pregnant women, children and others who are immune compromised, as mosquitoes can carry diseases. Since we cannot control bodily secretions or our blood type, both of which play into our chances of getting bitten, the best options are various forms of repellants. So, for people meeting the aforementioned conditions, the use of repellants is especially important during those rough mosquito-ridden summer months.

　

　

References:

Wang, S. (2009). Finding Smells That Repel. Wall Street Journal.

Knight, M. (2007). Why Do Mosquitoes Bite Some People More Than Others? ScienceLine.