How human-bite mosquitoes effectively hold us down is not currently known, but it is important, as they do not cause us itching. They also carry dangerous diseases such as Zika, dengue, West Nile virus and malaria which can be fatal.
In fact, stopping these annoying insects in their tracks could save the lives of half a million people who lose them every year.
“In every case where a mosquito has evolved to bite humans – which has only happened two or three times – it becomes a vector of nasty disease,” said Caroline “Lindy” McCbride, an assistant professor of ecology and evolutionary biology at Princeton Neuroscience. Institute in New Jersey.
That’s why he wants to understand how they find and target humans.
Mosquitoes can give us smells
“Mosquitoes mostly choose what to bite based on smell,” said McBride, whose lab focuses on the Aedes aegypti mosquito species, which is specifically developed to bite humans.
Only female mosquitoes drink blood because they need to produce their eggs. While ignoring other warm-blooded animals, knowing how a female mosquito that carries the disease smells a person is a key query.
Once it becomes known, more effective insects – or baits to lure mosquitoes away from humans – can be made, saving lives, said Christopher Potter, a professor of neuroscience at Censorship for Sensory Biology at Johns Hopkins University.
If scientists can control their sense of smell, “we can really control what these mosquitoes do,” said Potter, who studied human-specific mosquito Anopheles carrying malaria.
Our smell is complex
Answering is not an easy question, since the smell of any animal is made up of hundreds of chemical compounds packed together in a certain ratio.
Every time a hungry female mosquito flies, she does complex chemical math in her little brain, discovering what a human is, what a dog is and what a flower is.
Odor library
McBride’s lab team created a library on the chemical composition of animal odors. “That data set doesn’t really exist – so we decided to go out and collect it ourselves,” said Jessica Zhang, a graduate student at McBride’s lab.
Zung has so far collected fragrance samples from about 40 different animals, including guinea pigs, rats, quails and more.
A common compound stood
Comparing some of them with 16 human specimens, something jumped. Decanal, a simple, common compound, is abundant, especially in human skin, Zung said.
Understanding what mosquitoes smell is part of the story; It is also important to know how it works. To see exactly how mosquitoes use this meaning, scientists raised genetically modified Aedes aegypti mosquitoes so that we could cut off their tiny heads and place them under a microscope, and neurons when they came in contact with human and animal odors. Could see the firing, ”McBride said.
The research team already knows that mosquitoes have about 60 different types of neurons that sense odors, so when they looked into the insects’ brains, they thought they could see a lot of activity. But it was surprisingly quiet, meaning the signal was probably fairly smooth, with only a few types of neurons.
This type of research has only been possible since the technology for detailed study of mosquito studies became available, which has only recently happened. “It’s traditionally very difficult to study this at the level we’re doing it now,” Potter said.
An example of rapid evolution
Surprisingly, the mosquitoes that target humans have only been able to do this in the last 5,000,000 years, so it’s a “truly amazing example of rapid evolution,” McBride said.
Aedes aegypti, also known as the “yellow fever mosquito”, has dengue, Zika and chickenpox. McBride states that the critic originated in Africa and probably entered his current range on slave ships in the South 1600s, South United States and Central and South America.
They are easy to keep away
As for the intuition of how to avoid being bitten in your own backyard, McBride said he uses a fan.
“Blow air where you sit outside or on a barbecue or under a table where they bite your leg.” It’s not like you’re spreading the scent around to kill mosquitoes, she said.
It’s just that these deadly creatures, McBride said, “are not great flyers.”
Former geologist, Starrer behavior An science journalist and dog runner who lives on an island in Puget Sound, near Seattle, still picks up stones wherever he goes.
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