The term ‘mosquito’ comes from the Spanish meaning ‘little fly,’ or ‘my shoes are sad,’ depending upon which region of Latin America you happen to be saying it in. Pretty much all reasonable people hate mosquitoes, and for excellent cause. Every waking moment, all over the world, mosquitoes are plotting to abscond with our precious blood. And the manner in which they carry out this sub rosa crime is surprisingly clever and underhanded. When all is considered, the modus operandi of the mosquito is less like that of an annoying winged arthropod and more like something you’d see in the Oceans Eleven/Twelve/Thirteen series. Instead of piles of cash in a casino, it’s the tasty blood flowing through a high-security mammal that they’re after. And so the game begins.
To be sure, the mosquito (Family Culicidae, Lit. ‘Flying Grifter’) is one high-tech criminal. For starters, they’re equipped with chemical sensors that can detect trace amounts of CO2 and octenol in your exhalations. That’s how they find and track large sources of blood (they call them ‘marks’) from a distance. Once at close range, the mosquito surveils from a fake plumber’s van, then switches to thermal receptors on their antennae to guide them the last few meters – often in the dark. By the way, it’s the female mosquitoes who do all the biting. Apparently, they require large amounts of iron and protein to sustain their eggs. Why this has suddenly become our problem, we’ll never know. But it somehow has.
With a suitable iron-rich mark selected, the mosquito lands and deploys a microsurgical instrument called a proboscis, which was previously constructed to the mosquito’s exact specifications by the Don Cheadle character. Among other curious things, the proboscis contains two tubes – one used to withdraw blood and the other to inject special saliva. Why the special saliva? The reasons will be laid bare as the plot unfolds.
In order to feast on our blood for the minute or so she requires, the mosquito must suppress and somehow overcome a massively redundant, top-notch security system. Like casinos and their cash, we humans aren’t exactly giving away blood. We actively discourage crimes throughout our sprawling vascular system with myriad, expensive (w/r/t energy) defenses. For starters, there’s our complicated clotting mechanisms with their infamous plasma coagulation factors. Past that, there’s the vasoconstriction pathways which limit blood loss by reducing the diameter of the vessels carrying said blood. On top of that, there’s our sophisticated immune system with its swift, local inflammation response (plus red lasers criss-crossing the floor). And finally, let’s not forget the world’s most advanced central and peripheral nervous systems that continually monitor everything and instantly inform us of an intrusion in any sector, however slight.
A daunting task by any measure. But it’s a walk in the park for the female mosquito, even without the help of a small Chinese acrobat. She’s smooth, cool and professional. After landing, she removes her flight helmet, releases her long flowing hair from a bun, and jams her proboscis through the skin to begin probing for a vessel. She then injects a biochemical cocktail specifically formulated for the task at hand. Mosquito saliva contains an anticoagulant and a molecule to counteract vasoconstriction. Together, these chemicals keep our vessels wide open for business while she loads the duffle bags.
She also injects us with a mild pain killer (to buy her some time) and numerous other molecules that scientists believe may further suppress our immune system’s inflammation responses. In essence, these techniques are the biological equivalent of patching pre-recorded video of vacant rooms and hallways into the casino’s TV surveillance system. The brain (security HQ) has no idea what’s going on. Alas, her tricks work only temporarily – maybe for a few minutes — but that’s all she needs to get in and get out with the loot.
In the end, we’re left with a big pile of missing blood, and an itchy red bump – the mosquito’s calling card – which we notice as our immune and nervous systems finally come back online. Great work, immune and nervous systems. Thanks. Way to be. Of course, as the mosquito flies off into the night, there’s one more surprise in store for us. Depending on our geography, we might also now have any number of additional problems1 including malaria, yellow fever, dengue fever, West Nile virus, encephalitis and even elephantiasis2.
Here’s where the mosquito looks back over her shoulder and sneers, ‘That should keep ‘em busy for awhile.’ Or just makes a buzzing sound.
(The final grade may surprise you. Sure, there’s a great case to be made for failing the animal that kills more people annually than any other, except Great White Sharks. And without a doubt, the world would be a happier place minus mosquitos. But that being said, you have to respect a criminal who can pull off a job like this.)
1 Each year, more than 700 million people will be affected by a mosquito-borne disease. To fully grasp how dramatic that number is, imagine 700 million people, all of whom are affected by an illness they got from a mosquito.
2 The one where you get the huge scrotum. Gross. Also note the proper spelling (and associated pronunciation), elephantIASIS. Not elephantITIS. Just saying. Oh and it’s caused by a microscopic parasitic worm. Double gross.