The Science of Summer: Mosquitoes

Humanity’s enemy, Nature’s Protector

If with the push of a button you could completely eradicate the entire mosquito population from the face of the earth, would you? For most there wouldn’t be much hesitation, but you may need to reconsider because this question is not as hypothetical as you may think.

The mosquito is often labeled as the most despised creature on earth. This goes beyond the droning, terrible buzz you hear at night just as you close your eyes and start to get comfortable. It is argued that mosquitoes cause more suffering than any other organism through the diseases they spread — yellow fever, dengue (breakbone) fever, chikungunya, encephalitis, filariasis and malaria — which, on their own, are responsible for roughly half of all deaths in the history of the human species and still kills millions every year.

To eradicate them completely does sound tempting. Certain biologists even argue mosquitoes don’t have a significant role in the ecosystem and aren’t a particularly useful source of nutrition to predators due to them being so small. Considering that, along with the misery they cause, it may be hard to even feel guilty about killing them all. Before you press that button though, there are a few things that may change your view on the matter; however, the reasoning behind them requires a stretch of the imagination, a little bit of mental flexibility and a non-human perspective.

These creatures have been around for 50 million years and we cannot truly foresee their impact on the ecosystem. Not only are they competitors, certain species are important pollinators. The males don’t suck blood and are just as content living out their short lives drinking nectar. The female mosquitoes are the only ones out for blood, but getting a blood-meal is the single most dangerous thing a female mosquito could possibly do. So why risk their lives? Nectar from plants may be enough to sustain a single male mosquito, but the female has more than herself to think about. A female mosquito may lay up to 300 eggs at one time and the only way she can get enough nutrients to nourish those eggs before laying them is from blood. So in a way, every time you get bitten by a mosquito you can simply think of it as the selfless, nurturing act of a caring mother.

These reasons probably aren’t enough to sway you though. They weren’t for me either. What finally swayed me was something science writer David Quammen wrote in a piece for Outside magazine titled “Sympathy for the Devil”. In it, he explored the redeeming qualities of the mosquito. One sentence from that article completely changed the idea of mosquitos as a problem:

“The chief point of blame, with mosquitoes, happens also to be the chief point of merit: they make tropical rainforests, for humans, virtually uninhabitable.”

Human expansion has been encroaching on plains, forests, valleys and hills, all the while pushing and manipulating nature to our whims and desires. We made rivers out of deserts and brought mountains crashing down, leaving few precious untouched places. How have relatively large areas of rainforests avoided our touch?

Throughout history, due to their disease vectoring tendencies, mosquitoes made rainforests incredibly difficult to colonize. This is a main reason the world’s rain forests have remained relatively preserved.The mosquitoes have been there fighting for these ecosystems on the frontlines of the war against humans, delaying massive deforestation for the past 10,000 years.

However, as technology increases, so does humanity’s ability to eradicate obstacles and inconveniences, mosquitoes being no exception. Oxitec, a british biotech company, created genetically modified male mosquitoes with a special “assassin” gene. As they breed, they pass on the gene to the next generation. When the larvae hatch the modified gene activates and kills these larvae before they can grow into adults and breed. This method has been put to trial in Brazilian cities like Mandacaru, which suffers from high numbers of deaths due to dengue fever, a mosquito transmitted disease. The mosquito population was reduced by 96 percent. This of course can be viewed as a huge success, but expansion of this method is starting to raise concerns much closer to home.

In 2009, a New York resident caught dengue while vacationing in the Florida Keys. This was the first reported case of dengue in the U.S. since its eradication 60 years earlier and 63 more cases followed through November of 2010. Through joint efforts, the situation was controlled and no new cases have been reported since, but Oxitec is still planning on releasing the genetically modified mosquitoes as a trial in Florida. Petitions are currently being signed to prevent these trials.

On an even larger scale, reports that in order to brace for the 2016 summer olympics, Brazil might be the first nation to approve a large-scale release of these genetically modified mosquitoes. The trend to eliminate the threat of diseases carried by mosquitoes in major urban cities and towns is a noble cause. What’s worrying is the method of mass eradication that pushes the boundaries farther for our convenience when we don’t know the effects they may have.

It is important to remember that the underlying issue doesn’t lie with the mosquitoes themselves, but with the parasites that they may carry. The United States rarely suffers from incidences of malaria because there is no malaria for the mosquito to contract in the first place. Take away the true culprit and they are just another pest, but that’s no reason for hatred. Don’t get me wrong, if I see a bloodsucker land on my arm, I won’t hesitate to swat it. I don’t plan to cherish every mosquito life I come upon, offering my blood as a sacrifice to their timeless cause, but I will acknowledge and respect these tenacious little guys. By following their simple evolutionary programming, they have been keeping us in check for thousands of years.

Mosquitoes may always be labeled as the bad guy, but it’s important to remember that’s just from a human perspective. Let’s imagine how humans and mosquitoes compare from nature’s perspective — it seems quite obvious which nature would consider the harmful pest and which it would consider the protector.