It is understood that every living thing that makes up Nature, from the smallest insect to the largest mammals, plays a part in the planet’s vast ecological system. Yet given their well known annoyances and dangers to humans, it is natural to wonder what mosquitoes contribute. Are mosquitoes useful in any way?
The downsides of mosquitoes are widely recognized. They are vectors for many diseases. Each year, thousands die from illnesses carried by mosquitoes, including dengue, malaria, yellow fever, encephalitis, West Nile virus, and other illnesses. In some regions, these insects swarm around wild animals such as caribou, sometimes suffocating or harming them as the swarms press in.
They serve as food for other species to a degree.
Yet these Diptera fulfill a basic ecological role by feeding other organisms across ecosystems. In the Arctic, for example, their biomass forms a dense layer on the tundra that serves as sustenance for many migratory birds.
Some scientists argue that eradicating mosquitoes in these regions could reduce the number of migratory birds seeking food there.
There are numerous fish, spiders, frogs, salamanders, turtles, dragonflies and lizards that prey on mosquito larvae, making them easy prey for predators. If these predators lose a portion of their diet, the balance of local food webs could be affected.
Yet a consensus exists in part. Winifred Frick, a biologist at the University of California Santa Cruz who studies bats, notes that while mosquitoes support many species, they are not strictly essential. In other words, a hypothetical total disappearance of these insects would not necessarily devastate the predators that rely on them.
Regarding bats, Frick observes that no bat species specializes in mosquitoes. In fact, most bats are generalist hunters, eating whatever they can catch, including mosquitoes, beetles and countless other insects.
In the case of other species that depend on them for food, the potential complete eradication of mosquitoes has not been studied as thoroughly as for bats. Marm Kilpatrick, an ecologist at the same university quoted by National Geographic, suggests that most people might not notice a major impact if mosquitoes were removed entirely.
In short, many ecologists consider the risk of saving humanity from damage caused by mosquitoes to be compatible with ecosystem needs since these insects are neither the sole nor the most reliable food source for many species. Diets would shift, but ecosystems would adapt.
Positive outcomes for global health
If a selective extinction of mosquitoes were to occur, there would likely be health benefits for humans. The World Health Organization highlights the toll of mosquito-borne diseases. Malaria alone causes hundreds of thousands of deaths annually. Data from recent years point to 400,000 yearly malaria deaths in some reports.
The same line of thought applies to recent Zika outbreaks and its associated dengue and yellow fever risks. Dengue is responsible for tens of thousands of deaths each year, while yellow fever claims a significant number as well.
Humans are not the only species affected by mosquito-borne diseases; many animals suffer as well in the ecosystems they inhabit.