We were just up at a lake where mosquitoes make up most of the local wildlife. After counting over 200 mosquito bites (she actually took a mirror and counted all of her bites), Alexandra asked me how many mosquitoes it would take to kill you.
I guess you would first need to define what it means for a mosquito to kill you. For me, this can not mean getting West Nile Virus or something else from the little midges, it means that the mosquito actually does the physical killing themselves.
There are several ways that this could happen. The first and most obvious is that they could suck enough of your blood to kill you. This means that you would need to loose more than 40% of your blood, or more than 2800mL. A mosquito can take anywhere from 0.001 to 0.01mL of blood, so it would take between 280,000 and 2,800,000 mosquitoes all getting at you at the same time. Believe it or not, that’s over 15,000 lbs of mosquitoes. I’m pretty sure that more than enough weight to do the trick. But either sucking blood or crushing you would mean that they can all get to you… 2.8 Mil mosquitoes take up about 22,400 cm2. An average adult human has about 18,000cm2 of skin surface area, so a good number of the little guys will have to wait in line. In the crushing you scenario they would all have to be on one side of you, and one exposed side is less than half of that area, and your body can handle the dispersed weight of the little vampires of the ones that could land at one time.
I’m not even going to go into the math of how fast you create blood vs. how fast mosquitoes can take it out…
The next option would be that an overdose of their venom could kill you… but its not venom. Its mosquito spit and its mostly protein. It is designed to block blood clotting so they don’t get turned off at the pump. I searched really hard to find out what an overdose of mosquito spit would do, but there is surprisingly very little research on this topic. (They are in the process of creating a machine to harvest mosquito spit for blood thinning studies to help heart disease patients.) I did find an odd reference to a study that found repeated exposure to the stuff actually creates a tolerance in your body and mosquitoes will stop visiting you… so you won’t die from spit.
I did come across something surprising in my countless hours of research for this post; there have been reported bovine deaths where the cause of death was discovered to be asphyxia due to the nasal cavity being clogged with mosquitoes. Mosquitoes are drawn to CO2 (your breath) and given the chance, they will aim for your face. If you had enough of them right around your nose, and you breathed in deeply enough… This would still take several thousand all hanging out around your upper lip. (The mental image I conjure up for this looks like a really bad mustache.)