At certain times of the year, it can feel like mosquitoes are practically unavoidable. Who hasn't had a summer night interrupted by an uncomfortably close bzzz in your ear?
While it's not exactly a day for celebration, World Mosquito Day (August 20) does present us with an opportunity to learn more about the infamous mosquito, bring awareness to the dangerous diseases that it can carry, and highlight some of the incredible science being used to fight back!
Are you always the one in your friend group getting harassed by mosquitoes?
It's likely no coincidence. Mosquitoes "sniff" out their prey primarily through the use of their ultra-sensitive antennae, which pick up subtle concentrations of exhaled carbon dioxide, body odors, and other chemical compounds given off by animals. Once locked onto a scent trail, mosquitoes will use their eyes, temperature-sensing organs, and chemical-sensing mouthparts to find the ideal place to bite.
If you tend to be more sweaty, breath more rapidly, or simply give off more of a "human" smell than those around you, mosquitoes are likely to view you as more scrumptious. In addition, soaps, perfumes, and laundry detergents with floral and fruity scents appear to attract more mosquitoes, so consider using those that instead feature fatty acids (like coconut oil) or are unscented, which some research shows are less attractive to mosquitoes.1
A strong scent isn't the only factor that leads to being bitten, however. Researchers have found that blood type could play a role as well; mosquitoes may be more attracted to those with type O blood, according to preliminary studies.2 Unfortunately, for some of us it seems that being mosquito bait is simply built into our genes, with certain DNA sequences being correlated with higher mosquito attractiveness due to the chemicals they cause us to produce.
Did you know that mosquitoes are responsible for more human deaths than all other animals combined? In truth, it's not the mosquitoes themselves, but rather what they carry inside them. Their bloodsucking habits assist in the spread of pathogens that cause diseases such as West Nile virus, dengue fever, yellow fever, and malaria.
Malaria is particularly insidious, killing more than half a million people per year. Caused by a parasite in the blood, malaria goes so far as to cause infected individuals to produce more of a mosquito-attracting compound, thus promoting the spread of malaria.3
Scientists have been working for decades to develop ways to prevent or reduce the impact of these diseases. In the last several years, a vaccine for malaria has shown promise by reducing malarial infection in individuals by up to 40%,4 as has the use of beneficial bacteria to reduce dengue-carrying mosquito populations.
Genetic engineering is also playing an increasingly important role. Using CRISPR-Cas9 and a technique called "gene drive," scientists have been able to successfully modify the genes of mosquitoes, leading to a reduction in their population in certain areas and a reduction in the spread of disease. Read more about this cutting-edge method here.
There's no question as to whether mosquitoes, flies, gnats, and other biting insects are annoying—even deadly. But these insects also play an important role in their respective food webs as prey items. Many animals feed on mosquitoes, their larvae, and their kin, including bats, frogs, fish, small birds, lizards, and other insects. These animals, in turn, are vital to the larger food webs within their ecosystems.
It's also important to note that of the over 3,000 extant mosquito species, most do not actually feed on blood, and of those that do feed on blood, it's only the females that do so. They need the proteins and nutrients from blood to assist in the production of eggs. The majority of mosquitoes—and all male mosquitoes—feed on nectar and honeydew (a sweet secretion produced by some insects), which means that they often act as pollinators, too.
So, as detrimental as they can be, without mosquitoes, the world would be a very different place!
Sources:
.svg)
.svg)
