Hi, I’m John Green, author, vlog brother, and whatever the opposite of a mosquito enthusiast is.

You never want to get up close and personal with mosquitos… unless it’s like this, a microscope’s distance away. Under the lens, the mosquito undergoes a transformation of sorts.

Before, it was a pesky, biting insect whose presence was felt at best through the itchy bumps left on our skin, and at worst through a whole slew of diseases. But under the microscope, mosquitos undergo a metamorphosis sculpted in gold. The buzzing body takes on a life of its own, its usual role as menace lying far beyond the margins of the screen.

The mosquito is beautiful, a sentence I never expected to say, and that I assume you never expected to hear. Even the parts that are less elegant become charming, like their legs. They may look like a Christmas tree that’s collapsed into a pile of Cheeto dust right now.

But when you think about the tiny hooks along their surface that allow the mosquito to latch onto surfaces, and of the scales that help repel water so they can walk across ponds… well, then you start to realize you’re looking at  an incredible feat of, you know, feet. And of course, there are the wings, which are always an impressive part of nature to witness in action. Along the edges, you can see scaly hairs that the insect uses to process its surroundings.

Mosquito wings are unique in several ways. They’re unusually long and narrow, and they flap at an incredibly high rate, even compared to other insects of their size, around 800 times per second. To learn how those wings work, scientists needed to use high-speed cameras capturing 10,000 frames per second so they could distinguish each step of that rapid movement.

And in the process of flying, the movement of the wings creates the buzzing that warns us a mosquito is nearby. It’s an infuriating noise when it’s right against your ear. But for the mosquitos, it’s a signal, an instrument that guides them towards each other.

Male and female mosquitos will even go so far as to converge on the same wing-flapping frequency when they are courting. And with that image in mind, we’ve conjured up a vision of the mosquito that is both   beautiful and romantic, flirting wistfully through wing flap patterns. All it takes to shatter that notion is this part, the proboscis.

This is what allows the mosquito to drink from us. At first, the proboscis looks like a simple instrument, like a very poke-y straw that connects with our blood vessels. But in reality, it is a complex machine, made up  of six thin spear-like structures called stylets.

Two stylets hold the tissue apart while another pair act like drill bits digging through our skin. And then a stylet called the labrum sniffs out blood vessels using receptors that turn our body’s chemistry into a map. And when it does find the vessel, the labrum converts itself into a pipeline, carrying blood to the mosquito.

The sixth and last stylet helps the labrum with its task by injecting mosquito saliva into our blood vessels. This is not just gross mosquito backwash. Mosquito saliva contains enzymes that dilate our blood vessels and prevent our immune system from responding.

At least, that’s what the female mosquito does. Because all of this work, it’s not actually to provide the mosquito’s main meal. Mosquitos sustain themselves on nectar and fruit juices.

Blood, on the other hand, is about the next generation, and the eggs that will make them. So male mosquitos don’t consume blood. Their proboscis isn’t even strong enough to pierce our skin.

But female mosquitos need blood for reproduction, using the nutrients— particularly iron— to fuel the growth of their eggs. Over her lifetime, the female  mosquito may lay around 500 eggs. So if the physical discomfort that follows a bite is not enough misery for you, rest uneasily in the knowledge that your blood has fueled the birth of  the next round of mosquitos that will plague you, and the world.

And “plague” is the obvious word to go with when it comes to mosquitos. The Centers for Disease Control and Prevention call mosquitos “the World’s Deadliest Animal” because of the essential role they play in spreading disease. A shortlist of mosquito’s notorious  diseases includes malaria, dengue, West Nile, Zika, and lymphatic filariasis.

The actual organisms responsible for these diseases include protists, worms, and viruses. But their spread is driven by mosquitos, hopping  from person to person to get their blood, and leaving behind an unwanted memento of the microcosmos when they leave. Malaria, for example, is the potentially fatal work of parasitic protists that belong to the genus Plasmodium.

When an infected mosquito bites a human, the plasmodium quickly travels to the liver, usually reaching its destination in 20 minutes. And then the parasite reproduces, moving through different stages of their  life cycle as they infect red blood cells. When another mosquito comes along for blood, it will end up taking some of the parasite with it, keeping the cycle going and going and going.

In 2021, there were 247 million cases of malaria worldwide, and 619,000 people died from the disease. To try and prevent these deaths, humans have tried many strategies to curb the mosquito population or their ability to spread disease. Insecticides, genetic engineering… there have been a wide range of tools.

But we want to end with the one that resonates most with the microcosmos. It would look kind of like this, an array of ciliates borne across the skin of a larva. When scientists have pitted the vorticella— a Journey to the Microcosmos favorite— against the larvae of certain mosquito species, the mosquitos have fared quite poorly.

It’s not clear why or how, but the mosquito larvae die. The vorticella might prevent them from staying on the surface of water, getting in the way of their respiration. Or the vorticella might simply be poisoning the  mosquitos with chemical secretions of their own.

And if only the mosquito weren’t a mosquito, perhaps we could sympathize. Because we know the plight of a pest attached to our skin,   leaving behind misfortunes both small and deadly. But the microcosmos is the beginning and end of so many journeys, and even the mighty mosquito— the vector of so many diseases— can find its own wanderings cut short .

Thank you for coming on this journey with us as we explore the unseen world that surrounds us. We also want to say thank you to all of those people whose names you’re seeing on the screen right now. Those are some of our Patreon patrons and we could not continue to make this show without them.

If you’d like to see more from our Master of Microscopes, James Weiss, you can check out Jam and Germs on Instagram. And if you’d like to see more from us, there should be a subscribe button somewhere nearby.