Mosquitoes! These pesky little creatures seem to serve no other purpose than purposefully annoying us as we enjoy the great outdoors, and spreading dangerous diseases to us and our loved ones. If all mosquitoes were wiped off the face of the planet tomorrow, then the world would be none the worse for their absence – in fact, it would be a lot better off! Why then do these blood-sucking insects continue to exist? Read on as we attempt in this post to answer that vexed and perplexing question.
What is the purpose of mosquitoes?
This question actually can be interpreted in a couple of different ways. On the one hand, it could be asking why mosquitoes evolved, to begin with, given that they seem to be of no benefit to other species or the world in general. Framed in this way, the question actually makes no sense, because evolution doesn’t have a way, it is not a purpose-driven process. Organisms change, ie. develop mutations, automatically, the environment they live also changes automatically, and those entities which are best equipped to prosper in the changing conditions survive and reproduce (generating more mutations), whilst the others fall by the wayside. This is how evolution works! So for mosquitoes, no less than any other species, there doesn’t need to be any reason for why they evolved in the first place. And their continued survival doesn’t depend on them providing any benefits to the world either! After all, there are many species of parasites who survive solely by leeching off some host species. Why do they exist? Because they can! The same is true for mosquitoes. As long as they are able to find enough food to sustain themselves and their offspring; and as long as there are no natural selection pressures working against them (eg. a species that competes and takes resources off them); they don’t need to benefit anybody else besides themselves.
The second way this question can be interpreted is as follows: mosquitoes deliver no benefits to our species or seemingly to any other. In fact, if you ask any public health official, they are a source of net harm to home sapiens, what with the often fatal diseases they carry and infect us with. In fact, millions of human lives have been lost to Malaria, Dengue Fever, and a host of other deadly maladies. Public health systems have been stretched to breaking point battling these public health crises, eating up resources that could have been put to use saving lives elsewhere. And new parasites capable of using mosquitoes as a disease vector (carrier) are always evolving. Why then do we allow mosquitoes to continue to exist, why have we not yet managed to exterminate them? The answer to this question is very simple: we’ve tried but failed. Everyone knows the threat posed by mosquitoes. In fact, enormous funds are being allocated by nations and by international bodies like the World Health Organizations to research on how to eliminate mosquitoes entirely, and remove a major public health threat – including such drastic measures as genetic engineering and DNA modification. The truth is that we just haven’t yet come up with an effective means of exterminating these pests!
Or maybe we simply don’t care enough to develop one: after all, it is the poorest and most vulnerable regions inhabited by our species – the tropics and sub-Saharan Africa – who suffer the most at the hands of mosquitoes. Those of us in the developed world, where the technology is most advanced and the possibility of eradicating mosquitoes are most promising, are largely blind – sometimes willfully – to the sufferings of our brethren overseas.
Do mosquitoes provide benefits to other species?
Maybe, however, we are looking at the ‘mosquito question’ through an overly human-centric lens. After all, we are just one species among many millions that inhabit this beautiful planet – is it not true to say that some of the OTHER inhabitants of this planet might find these little pests a tad more useful than we do, insofar as they constitute a source of food for them. For example, up in the frozen tundra of the Arctic circle, mosquitoes form thick clouds that provide easy pickings for the birds that nest in the region. Elsewhere, mosquitoes – and mosquito larvae – are a major food source for frogs, lizards, spiders, fish and some other animals as well. Certain species of fish, like the mosquitofish or the gambusia, seem to almost specialize in consuming mosquito larvae.
Another possible benefit of mosquitoes is that their larvae consume large quantities of organic matter in the wetlands; when larger creatures higher up in the food chain eat the mosquito larvae, those nutrients are recycled back into the eco-system. In addition, as well as feeding on blood, adult mosquitoes like to sup on nectar – in fact, the males of the species consume nectar alone, and not blood – so a number of plants, like the northern orchids, might suffer from a lack of pollinating agents if mosquitoes ceased to pay them a visit.
These are some of the benefits arguably provided by mosquitoes to the global ecosystem. Looked at more closely, though, none of them are truly essential. Very few species rely on mosquitoes – or mosquito larvae – as their sole or major source of food; if mosquitoes were to cease to exist, these creatures would probably adapt very easily, finding some other source of food to supplement their diets. The function performed by mosquito larvae in recycling organic nutrients back into the food chain could be taken over by other types of larvae and water-borne creatures. Finally, the plants that depend on mosquitoes to pollinate them, are not exactly essential to the health of the ecosystem at large.
It can be said with some justification that mosquitoes serve no useful purpose, either to us or to most of the other inhabitants of planet Earth. In fact, as far as homo sapiens are concerned, these airborne insects are a source of great annoyance and harm. But, then, mosquitoes don’t have to serve any purpose – the concept of ‘purpose’ is not one which applies to our modern understanding of the natural world and of evolution. From the mosquitoes’ point of view, their ‘purpose’ is simply to survive and reproduce – the same as any other creature. And even if we wanted to eradicate mosquitoes due to their lack of utility to our species, as of yet we simply haven’t been able to! All mosquito-eradication methods tried so far have failed. That then is another answer to the question of why do mosquitoes exist?