The Science Behind Why Mosquitoes Bite With Preference

Have you ever wondered why some people wake up covered in mosquito bites while others are untouched?

The Science Behind Why Mosquitoes Bite With PreferenceMosquitoes are stimulated by a number of factors when seeking out for a bloody meal. Initially, they’re attracted by the carbon dioxide we exhale. Body heat is probably important too, but once the mosquito gets closer, she will respond to the smell of a potential blood source’s skin.

Studies have suggested blood type (particularly type O), pregnant women and beer drinkers all make you marginally more attractive to mosquitoes. Pregnant women are more attractive to mosquitoes than their non-pregnant counterparts and people with a greater body mass also appear more prone to bites. However, most of this research uses only one mosquito specie. Switch to another specie and the results are more likely to be different.

According to The Conversation, there are up to 400 chemical compounds on human skin that could play a role in attracting (and perhaps repulsing) mosquitoes. This smelly mix, produced by bacteria living in our skin and exuded in sweat, varies from person to person and is likely to explain why there is substantial variation in how many mozzies we attract. Genetics probably plays the biggest role in this. 

Doctors studying malaria transmission have revealed that it is all in the GENES.

The Science Behind Why Mosquitoes Bite With PreferenceThe way we protect ourselves against diseases like malaria could be revolutionized by the discovery that how attractive we smell to mosquitoes and other disease-transmitting insects may be genetically based.

For the first time ever, new research from the London School of Hygiene & Tropical Medicine (LSHTM) and other centres shows that, there is a genetic reason why mosquitoes bite some people more than others, likely to be caused by our genes’ control over our body odor. People who are less attractive to mosquitoes produce natural repellents that ward them off.

The Science Behind Why Mosquitoes Bite With PreferenceOne of the best studied substances contained in sweat is lactic acid. Research shows it’s a key mosquito attractant, particularly for human-biting species such as Aedes aegypti. This should act as fair warning against exercising close to wetlands; a hot and sweaty body is probably the “pick of the bunch” for a hungry mosquito!

Probably the most famous study about their biting habits demonstrated that the mosquitoes that spread malaria (Anopheles gambiae) are attracted to Limburger cheese. The bacteria that gives this cheese its distinctive aroma is closely related to germs living between our toes. That explains why these mosquitoes are attracted to smelly feet.

But when another mosquito (such as Aedes aegypti) is exposed to the same cheese, the phenomenon is not repeated. This difference between mosquitoes highlights the difficulty of studying their biting behaviours. Even pathogens such as malaria may make us more attractive to mosquitoes once we’re infected.

The Science Behind Why Mosquitoes Bite With PreferenceFemale mosquitoes need protein-rich blood for the energy required to mate and lay eggs. They display preferences for the smell of certain people when they choose whom to bite. However, these are not solely genetic. 

Researchers are trying to unscramble the irresistible smelly cocktails on the skins of “mosquito magnets”. But the bad news is that if you’re one of these people, there isn’t much you can do about it other than wearing insect repellents.


via The Conversation


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