They bite us in our sleep or while dining al fresco. Mosquitoes can spoil an evening so badly that we often find ourselves wishing we could wipe them out altogether.
But these bugs play a much more important role in our ecosystems than you might think. In conjunction with World Mosquito Day tomorrow, here are some fascinating facts about these annoying insects.
Mosquitoes can put our patience to the test with their incessant buzzing and, above all, their bites. When these insects draw our blood, they inject their saliva, which not only has anesthetic and anticoagulant properties but also causes itchy, red, swollen bumps on the skin.
In some cases, the effects can be far more serious. Mosquitoes can carry microscopic viruses and parasites that can cause serious or fatal illnesses in humans. These include dengue fever, chikungunya, Zika virus disease and malaria, which, collectively, were responsible for 608,000 deaths in 2022 alone, according to the World Health Organization.
Generally speaking, mosquitoes are the most deadly animal for humans – so it’s easy to understand why some people would like to wipe these insects off the face of the Earth. But that would be a mistake.
First, although we usually talk about “mosquitoes” as a homogenous group, the word is actually a generic term for some 3,500 species of insect, most of which feed on floral nectar. Barely 6% of mosquito species draw blood from humans, reports the BBC, and among them, only the females covet the blood of vertebrates to complete the maturation of their eggs.
In their search for nectar, other species of mosquitoes pollinate the flowering plants they visit. In this respect, they participate in the reproduction and dissemination of a multitude of plants.
In fact, researchers at Simon Fraser University in Canada state in a 2016 study that mosquitoes are generalist pollinators. In other words, they are capable of pollinating several plant species, which makes them particularly valuable for biodiversity and ecosystem resilience.
Mosquitoes are also an essential link in the food chain: they are a source of food for many animals, including bats, birds and frogs. And this is true whether they have reached adulthood or are still in the larval stage.
However, no predator is specifically dependent on mosquitoes for survival. So, in theory, the forced mass elimination of these insects should not lead to mass extinction; but certain ecosystems could be disrupted by this phenomenon, such as the Arctic tundra, where mosquitoes thrive.
While it would be unwise to eliminate all these insects, some scientists are in favour of eradicating certain types of mosquito, such as the infamous “nyamuk Aedes” (“Aedes aegypti”) and “Anopheles gambiae” (vectors of malaria).
Such is the case of the British biologist Olivia Judson, who, in an opinion piece in the New York Times dating from 2003, outlines the benefits of “specicide” – or the voluntary extinction of an entire species. In her view, this radical measure could save millions of human lives.
Other researchers are working to modify the genetic characteristics of mosquitoes, thereby reducing their disease burden. In recent years, agents from the World Mosquito Program have been organising regular releases of Aedes aegypti mosquitoes infected with “wolbachia”, a reproductive parasite that prevents the transmission of pathogens such as dengue or Zika viruses.
The aim is to deploy this bacterium in the Aedes aegypti mosquito population to make them less deadly. Perhaps this could help us finally find peace with mosquitoes.