China Science and Technology Museum
Autumn rain and cold
Summer passes quietly
What impression does it leave on you?
High temperature + sweaty clothes
And mosquitoes buzzing in the middle of the night...
html August 20th is "World Mosquito Day"
Although it is named "mosquito"
it is not established to commemorate mosquitoes
but to use by Raise public awareness of malaria
and other mosquito-borne diseases
Origin of World Mosquito Day
On August 20, 1897, British microbiologist and doctor Ronald Ross discovered in the laboratory that mosquitoes are the vector that spreads malaria. Due to this discovery, he won the Nobel Prize in 1902 Physiology or Medicine Award. Although humans have still not found a good malaria vaccine until now, Ronald's research at least points out a good way to avoid contracting malaria: stay away from mosquito bites. Therefore, people designate this day every year as World Mosquito Day.
Of course, the "criminal evidence" of mosquitoes is not only the spread of malaria, but also its involvement in Japanese encephalitis , filariasis and dengue fever . From this point of view, it is not too much to set up a special day to "commemorate" it!
How do mosquitoes accurately “attack” humans?
In fact, the positioning system of mosquitoes is mainly divided into three parts: smell, vision and temperature. If you master these three basic functions, mosquitoes will really not worry about finding prey!
The human body produces a variety of volatile chemicals in daily life, and these substances can form small feather-like airflows, also called plumes, along with the external wind direction, human body movement and respiratory airflow. The mosquito's mandibular organ can sense the plume of carbon dioxide exhaled by the human body through receptors. Therefore, as long as mosquitoes keep an eye on them, they can find people wherever there are plumes.
In addition to smell, vision is also a major way for mosquitoes to track the human body. At a relatively close distance, due to the mosquito's darkening habit, it will be more inclined to attack black objects through vision. This is also why people wearing dark clothing are more popular with mosquitoes.
Another more obvious point is to track the location of the human body through temperature. This is especially obvious at night. Everyone must have experienced that you can't find mosquitoes when you turn on the lights, but there are always a group of mosquitoes next to your ears when you turn off the lights. The buzzing scene was such that I didn't even see a single mosquito, but there were quite a few slap marks on my face.
This is because when we turn off the lights and sleep, the back of the head is close to the pillow, and the heat will increase relatively. Therefore, mosquitoes will search for the body's heat, and the buzzing sound will follow. When the light is turned on, the heat emitted by the light will interfere with the judgment of mosquitoes, causing them to hide in corners and not dare to fly around. After turning off the lights, the largest heat source in the room is the human body, and mosquitoes can accurately locate it.
Where does the buzzing sound of mosquitoes come from?
Mosquitoes have no lungs and no syringes. Where does this buzzing sound come from?
To solve this problem, we have to mention mosquito wings. When flying to find a target, the mosquito's wings vibrate at a very high frequency , which can reach hundreds of times per second, and can push the air back and forth quickly. This is where its buzzing sound comes from. As for why it can only fly to It can only be heard near the ears, because the sound they make is too small, and the range of hearing is limited to the vicinity of the ears.
The deeper we understand the creatures that "fight wits and courage" with us all day
The greater the possibility of winning
On World Mosquito Day
say "Never See You Again" to mosquitoes!
Drawing: Qi Fangzhu
Proofreading: Yu Lingtao
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