Why do we not simply eradicate mosquitos? What would be the negative consequences?


Why do we not simply eradicate mosquitos? What would be the negative consequences?

In: 4690

They’re a vital part of the food chain, especially their eggs and young.

We’d be better off genetically engineering a sub species of mosquito that doesnt need blood to reproduce.

Then there’s no downside to them, without biting they wont spread diseases. And the food chain doesnt get fucked.

The ecosystem is delicately balanced and any time humans decide to play God and mess with it, things start getting effed up.

If you’re going to eradicate mosquitoes, many different fish species will starve to death as they feed off of mosquito larvae in water. This in turn affects the bigger fish going up the food chain.

Not to mention birds that also eat said fish, that are now without food.

Aside from being food for birds, bats, frogs etc., they also are pollinators. Not all mosquito species (which there are many of) bite. And from the ones that bite, only the females do so. Which means that floral nectar is a fundamental food source for them and in the process of searching for it, they pollinate many flowers.

I have a foggy memory that this was attempted somewhere. Florida possibly. I cant find any references now but there was a massive programme of trying to exterminate all mosquitoes, doing things like driving trucks spraying huge clouds of insecticide through the streets.

From what I recall they gave up because the DEET they were using was seriously damaging the whole ecosystem and the mosquitoes were still thriving.

I know that isnt very helpful but hopefully enough there to trigger someones memory or i have got it wrong enough that someone will be complelled to correct me with some useful information

My favorite example to talk about with this sort of stuff is the Chinese campaign under Mao, to eliminate pests which posed a risk to the country, one of these pests they were more successful in eliminating were sparrows. Sparrows ate the grain from their harvest, so they wanted to get rid of them, and they depleted their population to almost 0.

Now the issues with this, is that sparrows eat more then grain, they also eat… bugs! specifically locusts, and without the sparrows to keep them in check, the locusts in turn grew in population and destroyed the harvest themselves.

The moral of the story is to always be very careful when you are attempting to engineer the ecological balance. You’re almost always forgetting something, or simply not aware.

We don’t know for sure. Which is the problem.

We have a good idea of some of the consequences and we might choose to accept those consequences, but there will also be surprise effects that we don’t expect and we don’t know what those surprise effects will be. If we were going to eliminate an animal that’s already on the verge of extinction, we could make pretty solid guesses on the consequences because it’s already approaching that point. But mosquitoes are just about everywhere and play a big role in keeping the ecosystem the way it is now. There would still be an ecosystem without them but we can’t fully predict what it would look like.

Here in Houston last year (and I think this year) the city released some mosquitos that prevented them from reproducing. During this time period the scientists addressed concerns that it would upset the ecosystem balance in the swamp. Ultimately they said it would be fine because mosquitos are not the primary food source for any of the animals in the area. Hopefully someone can find the article(s) talking about that.

So to answer your question…we’re working on it.

So people are saying “the ecosystem is delicate,” and that’s true, but mosquitos are kind of a special case with some fun extra history and caveats.

America (and many other places) gave mosquito eradication a solid attempt in the middle of the 1900s. Malaria was a regular problem in the States before that, and they used a compound called DDT to to kill enough mosquitos that the disease was basically scoured from the country. DDT has a pretty famous history of being a bit of an ecological^1 nightmare. It’s not great for people (if I recall, it causes ~~cancer~~ pregnancy problems), and it was very bad for birds (specifically it weakens their eggs).

Those mosquitos are still around in America, but because they’re mostly nocturnal, the mosquitos you probably know (and hate) are a different kind – tiger mosquitos, a diurnal species from Asia – which were introduced accidentally in the 80s from cargo ships.

So while the ecosystem is indeed delicate and I’m not enough of a ecologist to say with any certainty, I don’t think mother nature would lose any sleep over the death of invasive tiger mosquitos. The bigger issue, I’d bet, is that the tools we have for eradicating them tend to kill *other* stuff, too.


^(1): More than one person has suggested the ecological and human health effects of DDT might have been over-reported. I haven’t looked into that, so don’t quote me as an expert on the matter.

Very interesting interview on this from NPR with a guy in the Navy, (USA), who was at the level of an admiral a d in charge of environmental issues. He basically said we don’t need them to maintain existing ecosystems. If they all disappeared tomorrow, everything would be fine.

The answer to the second question is the answer to the first: We don’t know.

There are researchers working on genetically modified mosquitoes who would pass on genes that ensure only males (who don’t bite) survive. They’ve been met with many of the same concerns brought up in other responses here, but they believe that other insects would fill mosquitoes’ niche in the ecosystem.

[First genetically modified mosquitoes released in the United States](https://www.nature.com/articles/d41586-021-01186-6).

The simplest answer to “why haven’t we eradicated mosquitoes” is that we’re still determining what the consequences would be, but it isn’t off the table.

I am a mosquito scientist and this is the most common questions I get asked! It’s a really complicated area with so many different aspects it’s hard to sum it all up! Here’s a brief summary:

The first thing to be aware of is there are about 3600 different types (species) of mosquito. Of these about 60 bite humans and spread disease. So we would only what to target these ones.

Over the years many chemicals have been used however over time the mosquitoes tend to become immune to the chemicals so they stop working.

Genetically modifying mosquitoes to stop then being able to reproduce is the latest method. It has shown to be effective at reducing the population in certain areas. However unless you do it on a whole island/ continent, unmodified mosquitoes will always move back in.

Land management to reduce suitable breeding sites also works however there is a lack of money to do this in most area and who impact the ecosystem.

In urban areas the Asian tiger mosquito is particularly annoying. The way to get rid if this is my removing any breeding site. However the breeding sites could be bits of plastic with a drop of water in them. So trying to get rid if this on a city wide level is almost impossible!


I’ve had lots of people saying I haven’t answered the question. So here is my attempt.

If we just look at the Asian tiger mosquito, which is an invasive species to many countries, it is unlikely to be part of a complex food web as it has only spread around the globe in the last few decades. Furthermore it lives in urban environments so unlikely to be the source of food for anything significant. Eliminating this species would just return us to where we were a few decades ago and not have much impact.

Concerning a the other species, I can’t really say! Sorry!

Mosquitos can be AFAIK eradicated without destroying any ecosystems, there might be a fringe case but this is generally true. The issue is eradicating ONLY mosquitos, they have begun to create genetically engineered mosquitos that will produce sterile offspring and then release them into the wild which has been having good results and is highly specific. Another maybe more cynical point to this is who can profit off of the elimination of mosquitos globally? I’m not saying that there’s a conspiracy to keep them around but it would take a government to step up fund research and pay for deployment of a technique to get rid of an annoyance (in America at least where malaria isn’t so much a problem) for the general population. Hell maybe we should crowdfund it.

Biologist here

There are literally thousands (more than three thousand!) species of mosquitoes in the world. Many of those do not ever bite people. Wiping out all of them would be pointless and destructive.

On the other hand, many of the worst mosquito species from a human perspective are actually invasive species that humans have accidentally spread around the world. A few others are human-specialists and don’t really engage much with ecosystems that aren’t dominated by humans (villages, cities, farms).

Wiping out _these_ species would likely not have many negative impacts on broader ecosystems. Might even be helpful by removing competition for native species.

_However_, historically at least, attempting to eliminate mosquitoes has been hugely damaging to the environment. Not so much because of the lack of mosquitoes themselves, but because eradicating mosquitoes was done by draining wetlands (vital habitats for many species, and important for cleaning and controlling water) and using pesticides (which killed many other species as well).

More recently there are some promising new genetic approaches that can be targeted at a single mosquito species. I have hopes that these may bring us some success in wiping out invasive mosquito species in at least some locations.

At the beginning of time there was a council of animals and it was determined that the human race needed to be exterminated because we are so fucked up. The vote needed to be unanimous. The mosquitoes stuck up for us.

If we exterminate the mosquitoes, we won’t have their veto/filibuster any longer and we will be exterminated due to a unanimous vote.

In Cuba there is a sector of the Health Ministry with the only purpose of eliminating the Aedes Aegypti (Yellow
Fever transmiter mosquito). Even some part of the mandatory military drafted are given the option to belong to that organism. Not an easy task. They go house by house, trying to eliminate the water accumulations (where larvae develops) and to backyards, open fields, spraying chemicals etc. Through the years the mosquito still is present but other insects have disappeared, the most visible the butterflies and cocuyos (cuban fireflies). They have decreased the incidence of the yellow fever, and meningitis, to the cost of the ecosystem. 10 years ago, i haven’t been able to see a single butterfly or firefly in the countryside, and little reptiles, like chamaleons -used to eat mosquitos, flies, and drink water from the poisoned ponds. Etc. Everything is connected.

Mosquitoes cause more human suffering than any other organism — over one million people worldwide die from mosquito-borne diseases every year. Not only can mosquitoes carry diseases that afflict humans, they also transmit several diseases and parasites that dogs and horses are very susceptible too.

Those damn blood suckers are responsible for more than HALF of ALL human deaths **throughout all of human history** – [Winegard](https://www.goodreads.com/book/show/42983957-the-mosquito) estimates that mosquitoes have killed more people than any other single cause—fifty-two billion of us, nearly half of all humans who have ever lived. He calls them “our apex predator,” “the destroyer of worlds,” and “the ultimate agent of historical change.”

– so by eliminating mosquitos – you’re taking out a major killer of humans. Now, what could possibly go wrong with that plan… ?

Because they are an endangered species in the galaxy and earth was actually set up as a reserve for the remaining population.