Mosquitoes might be humanity’s greatest foe. Should we get rid of them?

The pesky insect is the deadliest animal in human history

The deadliest killer in human history might not be guns or bombs, cancer or car accidents. It’s a pesky insect that most of us don’t think twice about: the mosquito.

Over the course of 200,000 years, 108 billion people have lived on Earth. And nearly half, 52 billion, have been killed by mosquitoes. The impact of this disastrous insect has shaped civilization far beyond our expectations, according to historian Timothy C. Winegard, whose new book, The Mosquito: A Human History of Our Deadliest Predator, explores this lethal insect.

Since the dinosaur era, the incredibly resilient mosquito has been a carrier of malaria, yellow fever, Zika, and a slew of other diseases that have ravaged human populations, with people in Africa bearing the greatest tolls. In The Mosquito, Winegard’s fifth book, he explores not only the disastrous consequences of mosquitoes on a biological level but also the insects’ social impact, including how they have affected GDP by taking millions of people out of the workforce and steered the course of history when used as a biological weapon in wartime.

I talked to Winegard, who currently teaches history and political science at Colorado Mesa University, about what makes mosquitoes “masters of evolutionary adaptation,” if they should be eradicated, and what kind of function — if any — they serve. I also asked him the age-old question of how to avoid mosquito bites (the key, he says, has to do with our feet).

Our conversation has been condensed and edited for clarity.

Hope Reese

What makes mosquitoes unique as a deadly foe to humankind?

Timothy C. Winegard

The mosquito is a nearly universal animal. We have 110 trillion across nearly all of the planet, and we’ve had them for over 100 million years. So the mosquito is global, whereas other insects have their ecological niches here and there around the world.

The other thing is that the mosquito transmits or vectors far more diseases than other insects. So for example, you have the assassin, or kissing bug [a tropical bloodsucking insect that transmits parasites like the one that causes Chagas disease], but that’s just one, whereas mosquitoes have parasites like malaria and numerous viruses and worms. So there’s such a multitude of diseases that different species of the mosquito transmit compared to other insects.

Hope Reese

How have mosquitoes been so adaptive?

Timothy C. Winegard

Like any other animal, including ourselves, it’s a process of natural selection and survival. So the mosquito has adapted to withstand global showers of DDT, for example, beginning after the Second World War. And by the time Rachel Carson writes her seminal book Silent Spring in 1962, there are already five mosquitoes that are immune to DDT.

Mosquitoes want to live and procreate and continue their species, so they adapt in order to do that — just like we have in our defenses against malaria; for example, sickle cell anemia is an example of us defeating the threat of mosquito-borne diseases through natural selection.

Hope Reese

So let’s back up a little. Can you talk about how you became interested in mosquitoes, both as a historian and someone with military experience?

Timothy C. Winegard

Well, I’m Canadian, so our onset of summer is signaled by hordes of mosquitoes — it’s just part of our culture. But on a more specific note, my teaching portfolio at the university ranges from Western civilization to American history to indigenous studies. Looking through all these books and reading, I think of history like a puzzle, and there were just pieces of this puzzle missing.

I sat down with my dad, who’s an emergency doctor, and we started chatting about disease. He mentioned malaria, and [I began] looking into malaria, mosquitoes, disease. Later, I was grocery shopping and I saw a giant display for Deep Woods Off advertising that it can repel mosquitoes that cause dengue, Zika, and West Nile. The historical puzzle pieces clicked together and that was kind of like, “Okay, this is now a no-brainer.”

When I delved into the research, there were so many examples of mosquito-borne diseases throughout history being far more lethal than man-made weapons or inventions from antiquity to the Second World War.

Hope Reese

How have mosquitoes been used in military operations?

Timothy C. Winegard

The Nazis purposely re-flooded the Pontine Marshes around Rome and Naples as a premeditated biological weapon to reintroduce malaria’s mosquitoes into that part of Italy during WWII. It was shocking to hear that — one, that they thought of that and did that, and then second, my wife’s grandfather was at Anzio, Italy, at the time and contracted malaria due to this. He had no idea about this.

So I told him in the spring of 2017, and it kind of pulled back the curtains in a way for him, for his war experience, and in his stoic, normal self, just basically looked at me and said, “Well, that makes a lot of sense.” Because there was a personal connection to the larger story of mosquito-borne diseases in the Second World War, that one hit home to me and to my wife’s family as well.

Hope Reese

You write that there’s an average of 2 million deaths per year caused by mosquitoes since the year 2000. How many of that number are from malaria?

Timothy C. Winegard

Those numbers are estimates. Malaria definitely accounts for the majority of deaths from mosquito-borne diseases. With yellow fever, there’s a vaccine now, so it doesn’t have nearly the death toll that it did in the past. Some of the other diseases now are generally not prolific killers, like West Nile and Zika, but for the people who do get the full-blown symptoms, it’s a horrible experience and it can cause death.

Since the Gates Foundation was established in 2000, with their amazing work trying to tackle mosquito-borne diseases and funding different research and trying to pump out mosquito nets and insecticides and malaria drugs into the less developed pockets of the world, we are seeing a decrease in overall deaths from mosquito-borne diseases, specifically malaria. Again, the numbers still vary, but generally speaking, we are seeing a decrease in deaths specifically from malaria, which is the paramount killer.

But on the opposite side, what we’re seeing in some of these other viruses is actually an increased threat of them spreading across the world. While malaria deaths are certainly decreasing, we’re seeing an increasing threat from Zika, West Nile, and dengue.

Hope Reese

You write about turning points in history that spurred more mosquito-borne illnesses. What are some of the big moments in history that have impacted the spread of these diseases?

Timothy C. Winegard

The domestication of animals in close proximity to mosquitoes creates zoonotic diseases where the spillover [happens] from animal diseases into humans. We see that with smallpox and tuberculosis, the common cold. So it became bad on that end. When we start stirring up our environments, cutting down trees, adding water, it’s a dangerous recipe for the proliferation of mosquitoes and mosquito-borne diseases.

The other factor is when we domesticate those plants and animals, the population densities increase. It’s easier then for diseases to spread because of the proximity of people to people, and mosquitoes to people, and animals to people. So it’s a whole funny package that creates the right environment for the zoonotic transmission of diseases from animals to humans.

Hope Reese

How is climate change affecting this?

Timothy C. Winegard

Increased temperatures mean a longer breeding season for mosquitoes. Canada has seen a 10 percent increase in mosquito-borne disease in the last 20 years. In the southern US, we’ve seen domestic cases of Zika, chikungunya, and even dengue in the last 10 years. So if temperatures rise around the planet, mosquitoes survive and breed longer, which increases the risk of spreading disease.

Hope Reese

Is there anything good about mosquitoes?

Timothy C. Winegard

We don’t know for certain. We do know that they don’t ingest waste like other insects, they don’t aerate the soil like other insects. Obviously other animals eat them, but not as an indispensable food source. And they do pollinate, because the males drink nectar, but they don’t pollinate the ways bees do. And only the females bite.

I allude to it in the book, and this is a touchy subject, but perhaps they are the pinnacle Malthusian check on uncontrolled human population growth.

We forget that we’re one animal of a ton that live on this planet, and we share our global village. Sometimes we’re driven by our own hubris to think we’re above other animals on the planet, which is not the case. The mosquito and other insects, like the kissing bug, are reminders that we’re not as mighty as we may think we are.

Hope Reese

Should we eradicate mosquitoes completely?

Timothy C. Winegard

There’s certainly a moral argument to be made that they devastate human populations and we should try to eradicate the diseases. I’m not choosing sides. Biologically, there’s an argument one way, but morally, there’s an argument the other way. This is something that scientists and biologists have been thinking about.

To use the Star Wars analogy, there’s a balance to the Force. And when there’s a disturbance in the Force, things go awry. To upset that balance by intruding on natural selection to eliminate all mosquitoes — and I don’t think that’s what anyone is promoting, since there are 3,500 mosquito species and very few transmit diseases — but perhaps the eradication of those that transmit diseases is extreme.

Still, a lot of the CRISPR research [which alters the DNA of mosquitoes] is geared toward making mosquitoes harmless by making them incapable of carrying diseases, but not harming the mosquitoes themselves.

Hope Reese

Eighty-five percent of what makes us attractive to mosquitoes is due to genetic factors. Can you explain? And what can we do to avoid bites?

Timothy C. Winegard

Blood type is one. According to studies, they prefer blood type O over A, B, or a blend.

But there are other factors [that affect the chance of attracting mosquitoes]. Don’t wear bright colors. Don’t drink beer. Exercise less — when you exercise, you discharge more carbon dioxide; that’s essentially a magnetizer for mosquitoes. Clean your feet. The bacteria on our feet is a mosquito aphrodisiac. Everywhere else on the skin is generally a deterrent, except feet. But most of it is hardwired into a genetic circuit board. There are myths about your hair color having an impact, or if you have darker skin or more leathery skin. None of that seems to be true.

But the best advice? Don’t go outside during peak mosquito hours! At the end of the day, people douse ourselves in bug spray, but if you miss one tiny area, she’ll find it! She circumvents our best repellents.

All Rights Reserved for Hope Reese

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