Mosquitoes! Those pesky little creatures seem to serve no other purpose than to deliberately annoy us as we enjoy the great outdoors and to spread dangerous diseases to ourselves 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! In that case, why do these blood-sucking insects continue to exist? Read on as we attempt to answer that vexing and perplexing question.
What purpose do mosquitoes serve?
This question could actually 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 any other species or to the world in general. Framed in this way, the question actually makes no sense. Evolution has no plan – it is not a purpose-driven process. Organisms change and develop mutations automatically while the environment in which they live also changes automatically. Therefore, those organisms which are best equipped to prosper in the changing conditions survive and reproduce (generating more mutations), while the others fall by the wayside. That is how evolution works!
So, for mosquitoes, no less than for any other species, it is unnecessary to have a reason why they evolved in the first place. Their continued survival does not depend on them providing any benefits to the world, either! After all, there are many species of parasites who survive solely by leeching off of some host species. Why do parasites exist? Because they can! The same is true for mosquitoes. There is no need for them to benefit anybody besides themselves 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 (e.g. a species that competes and takes resources from them).
Mosquitoes deliver no benefits to our species and seem to offer no benefits to any other species. In fact, if you ask any public health official, they will respond that mosquitoes are a source of net harm to Homo sapiens due to the often fatal diseases they can carry and infect us with. In fact, millions of human lives have been lost to malaria, dengue fever, and a host of other deadly mosquito-borne maladies. Public health systems have been battling these public health crises, which eat up resources that could have been put to use saving lives elsewhere. In the meantime, new parasites that are capable of using mosquitoes as a disease vector (carrier) are continuously evolving.
Therefore, the second way the question of the purpose mosquitos serve could be interpreted is: Why do we allow mosquitoes to continue to exist? Why have we not yet exterminated them completely? The answer to this question is very simple. We have tried and failed. Everyone knows the threat mosquitoes pose. In fact, enormous funds have been allocated by individual nations and by international bodies like the World Health Organization to research how to eliminate mosquitoes entirely, thereby removing a major public health threat. This research includes such drastic measures as genetic engineering and DNA modification. The truth is that we simply have not yet come up with an effective means of exterminating these pests!
Or, maybe we simply do not care enough to develop one. After all, it is in the poorest and most vulnerable regions – the tropics and sub-Saharan Africa – that people suffer the most at the hands of mosquitoes. Those of us in the developed world, where the technology is more advanced and the possibility of eradicating mosquitoes is most promising, can be largely blind to the suffering of our brethren overseas.
Do mosquitoes provide any benefits to other species?
Maybe we are looking at the mosquito question through an overly human-centric lens, though. After all, we are just one species among the millions that inhabit this beautiful planet. It may not be 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 their larvae are a major food source for frogs, lizards, spiders, fish, and some other animal species as well. Certain species of fish, like the mosquitofish or the gambusia, seem to be almost specialized in consuming mosquito larvae.
Another possible mosquito benefit is that their larvae consume large quantities of organic matter in the wetlands. Therefore, when larger creatures that are higher up in the food chain eat the mosquito larvae, those nutrients are then recycled back into the ecosystem. In addition, as well as blood, adult mosquitoes like to feed on nectar. In fact, the males of the species only consume nectar and not blood. For that reason, a number of plants, like the northern orchids, might suffer from a lack of pollinating agents if mosquitoes were to cease visiting them.
These are some of the benefits that it can be argued that mosquitoes provide to the global ecosystem. When examined more closely, though, none of them are truly essential. Very few species rely on mosquitoes or their larvae as their sole or major food source of food. If mosquitoes were to cease to exist, those creatures would probably adapt very easily, finding some other food source 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 other 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 to either human beings or most of the other inhabitants of Earth. In fact, as far as Homo sapiens are concerned, these airborne insects are a source of great annoyance and harm. But, keep in mind that mosquitoes do not 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 to reproduce – the same as any other creature. Even if we wanted to eradicate mosquitoes due to their lack of utility to our species, up until now, we simply have not been able to! All of the mosquito eradication methods that have been tried so far have failed. That is yet another answer to the question of why mosquitoes exist.