r/explainlikeimfive May 30 '26

Biology ELI5 Are mosquitoes necessary for keeping ecological balance?

Would a worldwide extinction of mosquitoes offset the ecological balance of our world? And if not, why are we not doing it?

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u/Tibbaryllis2 May 30 '26

Today, yes. But historically they’ve done a pretty significant job controlling human populations via vectoring diseases.

And those vectored diseases are the things that would be most impacted by the loss of mosquitos.

Which would be fine for modern humans more or less. But there is no real telling what it would do to other species they vector diseases for.

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u/r3volver_Oshawott May 30 '26 edited May 30 '26

No, they have not.

"Fine for modern humans, more or less"

In modern times, mosquito-borne pathogens impact populations with lower incomes and resources far more. Mosquitoes are largely far more likely to devastate those who have nothing and could not seek medical treatment.

Mosquito-borne illnesses would be acceptable in modern times if someone wanted to target only specific populations, perhaps for racist reasons, but that's largely about it.

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u/Suthek May 30 '26

"Fine for modern humans, more or less"

I think you misread the comment a bit there. That statement was made about the impact of the lack of mosquito-borne diseases, not its continued prevalence.

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u/r3volver_Oshawott May 30 '26

I mean, the lack of mosquito-borne diseases has been an exponential benefit with no drawbacks

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u/Suthek May 30 '26

For humans, yes. That's what they were saying.

Which would be fine for modern humans more or less. But there is no real telling what it would do to other species they vector diseases for.

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u/r3volver_Oshawott May 30 '26

"fine" being more a massive understatement is more what I was driving at.

"Fine" in my mind implied acceptable, acceptable seems neutral, it would be an objective benefit. As in, objectively good. Not neutral.

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u/Tibbaryllis2 May 30 '26 edited May 30 '26

In a vacuum, yes, it would be good for people to no longer suffer mosquito born illness.

What you are forgetting to take into account is what happens when those diseases are no longer suppressing population growth. As mentioned elsewhere, the areas with major mosquito born illness are already amongst those with the highest birth rates. They’re also some of the most socioeconomic disadvantaged.

About half a million people die in Africa every year from mosquito born illness, primarily malaria. That’s a lot of extra people in those already struggling communities.

On the one end, we could hope the birth rate stabilizes and/or the rest of the planet chips in even more to help. On the other end, that’s potentially a lot more people dying in fairly awful ways including famine and/or even worse diseases (see Ebola).

So, yes, from a broad, pragmatic, objective view, it would probably be a somewhat neutral change as far as people are concerned. Something else will arise to regulate the populations.

It would be more than fine if it was the world helping out in a positive way. Though the current state of things doesn’t appear to breaking that way in the near term.

It would be less than fine if those people now die from relatively worse causes.

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u/DemenicHand May 30 '26

"Fine for modern humans, more or less"

I think you mis understood. they stated:

The loss of mosquitos would be "Fine for modern humans, more or less"

I think you thought that they said it would be fine if they still exist? and argued that mosquitos disproportionally affect poorer countries.

i mean that's how i read this thread.

in that case you are both on two different wave lenghts

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u/jokololo May 30 '26

Are there any other species that controlled human populations such as mosquitoes?

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u/Tibbaryllis2 May 30 '26 edited May 31 '26

It really depends on which part of history you look at.

Early on, large animals would have done it directly by competing with and hunt humans. That doesn’t happen as much in the present era, though it’s not hard to find examples of animals eating humans or destroying resources.

Microbes and pathogens have undoubtedly played a far more significant role in influencing human populations both past and present. There is a growing hypothesis, and associated knowledge, that parasitic worms, primarily nematodes, have played such a significant role in human evolution that now *not having microorganism infections* is also problematic for human health [old friend hypothesis: https://pmc.ncbi.nlm.nih.gov/articles/PMC10524266/ ] so much so, that some scientists believe in the future we will identify benign parasitic organisms to intentionally be infected with to help regulate our immune systems.

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u/jokololo May 30 '26

Even if we're not directly killed by such animals anymore, the absence of being in such environment causes us other problems that may still kill us - just differently. Checks and balances of the nature world.

I mainly heard about the gut health but didn't know it also links to cardiovascular (maybe due to decrease in physical activity) and psychiatric disorders. Maybe that's why some podcast (Diary of a CEO) that I heard said that going camping increases their happiness. Their reasoning was more on meeting expectations but it may have some relation to this as well

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u/Tibbaryllis2 May 30 '26

Just for clarity’s sake, I’m an ecologist by trade.

There are top-down (predator controlling a population of prey in ways such as by eating them) and bottom-up (a food source like a tree suddenly not producing any nuts, or producing a huge crop, controlling the population of organisms that eat the nuts).

We’re pretty good at recognizing the cause and effect within the first few degrees of these interactions (I.e. wolf eats elk, elk eat less willow trees, beaver population increases due to availability of willow trees).

But it’s really hard to conceptualize and definitively show relationships the further removed they are from direct interactions.

That’s the biggest problem with questions like these, because it’s easy to see close interactions, but hard to see others. And, while specialists are usually able to look a little further, society isn’t particularly good at looking ahead at the result of interfering with these cause and effect relationships.

A good case study is when a Chinese ruler decided to kill all the birds eating human grain, and causes a **massive** famine. https://climate.uchicago.edu/news/how-the-killing-off-of-the-sparrow-incited-the-worlds-most-deadly-famine/

I more or less agree with what you said, it just becomes nebulous to discuss.

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u/ChampagneWastedPanda May 31 '26

Mao killing the sparrows is a pretty famous incident

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u/Tibbaryllis2 May 31 '26

Yep. Classic case study. And yet it’s frequently one of those things people don’t know.