Can’t we just kill them all? The war on mosquitoes

As someone who is considered a unique delicacy for mosquitoes, the idea of a world without them has definitely crossed my mind. Lying awake for nights on end with an unbearable itching sensation over my body is reason enough to consider wiping out the blood sucking pests.

As global temperatures are increasing, mosquitoes are shifting to locations they previously haven’t been able to successfully populate. The recent terrors caused by Zika virus has sparked scientists world-wide to stop and really consider this as an option. They too find themselves asking, what would the world be like without mosquitoes?

 

The facts

Not only are mosquitoes annoying pests that make us itch uncontrollably, they are also a major vector of disease. Common diseases carried by mosquitoes include malaria, dengue fever, yellow fever and the previously mentioned Zika virus, all of which have serious health consequences for humans.

Malaria alone affects over 200 million people annually, killing over 400,000. In fact, the mosquito has been labelled as the deadliest animal on Earth due to the havoc they cause through disease transmission. Considering how damaging these tiny suckers are surprisingly only a few hundred of the 3,500 named mosquito species actually bite humans.

We also know that mosquitoes are the main food source for many predator species and important pollinators. They have been on Earth for much longer than us and have evolved alongside many other species, indicating that the interspecific relationships formed over time may be vital to maintaining the current state of the ecosystem.

Now we know the roles mosquitoes play in our environment (both the good and bad), let’s consider a world where they do not exist.

 

The unknown

A world without mosquitos would be one ridden of many diseases. It would be a world where balmy summer nights aren’t ruined by being soaked in sticky, pungent insect repellent. The nights of lying awake anxiously listening to a faint ‘buzzing’ in your ear would be over. We wouldn’t need to worry about being covered in itchy lumps. Sounds pretty great, right?

Many scientists argue that eradicating mosquitoes from the world wouldn’t do that much damage to the ecosystem, and the niches they inhabit would quickly be filled by another species.

On the other hand, there are many who argue the opposite. Some species, such as the mosquitofish, feed only on mosquitoes. Their feeding techniques are so specialised and so established in their behaviour that removing mosquitoes from the food web would likely force the species to go extinct. In the Arctic, mosquitoes occur in enormous biomass swarms. Experts fear that removing this food source could alter the migration path for many birds and the flow on effects from this are unknown.

 

Not only are there unknown ecological consequences, but the feasibility of such an operation is questionable. We have tried to eradicate mosquitoes in the past with little success, using an extremely hazardous chemical called DDT. On top of there being no practical method at present, there is question of if it is even possible to kill all individuals, given the mosquito life cycle and population numbers.

 

The solution

Mosquito eradication may not be feasible nor desirable from an ecological perspective, but what else can be done? Researchers have suggested various methods of combating the spread of mosquito-borne diseases, some of which are currently being trialled.

Some scientists have found a bacterium (Wolbachia pipientis) protects the mosquito host from being infected with viruses such as malaria and Zika. Releasing lab-born adult mosquitoes infected with Wolbachia into a wild population would increase the number of offspring in the wild that are unable to carry viruses. From then on, only eggs fertilised by both male and female Wolbachia-carrying parents can survive. This stops any eggs not carrying Wolbachia from hatching.

This method allows mosquitoes populations to continue while removing the viral threats to humans. In the future, methods like this will likely be the answer to this problem, as we continue to strive for a world where humans co-exist peacefully with the other species they share the planet with.

 


3 Responses to “Can’t we just kill them all? The war on mosquitoes”

  1. Imogen Wallace says:

    Such an interesting article! It’s so important that we consider the ecological implications that eradication of one species can have on the rest of the world!

  2. ihockey says:

    Nice read Alice. With the escalation of Zika virus throughout the world, scientists have been trialling genetic engineering of mosquito DNA. Late last year GM mosquitoes were approved for field release in Florida. The male DNA was manipulated to maintain fecundity, but produce offspring that die early. The aim is to reduce the population of mosquitos that carry potentially fatal diseases like Zika or dengue fever. As Murraya mentioned, this is ethically contentious, as who declares which organisms have a right to live and prosper?

  3. Murraya Lane says:

    Really interesting read!! It was informative but also very relatable. I know I’ve definitely found myself lying awake at night wishing mosquitos didn’t exist… however it is a complicated issue and is it really ethical to eradicate an entire species? I hope the option suggested in your paper is effective and we can live with them, however it looks like my summer nights will still be spent itching!!!