There are thousands of ways to repel mosquitoes. One way seems to be particularly unreliable: put a cup of sugar in the room.
According to the legendary method, you have to prepare a sweet syrup, which can be packed in a bottle, or in a bottle, and then open the lid and put it in the corner. The sweetness of the syrup will attract mosquitoes. The attracted mosquitoes will fly into the bottle and stick to the sugar, so they won’t come to you.
Does it sound like a very unreliable trick? Because some scientists have previously shown that mosquitoes sense carbon dioxide, lactic acid, carboxylic acid, aldehyde and octene alcohol through the sense of smell to find blood-sucking objects, and sweetness is not their perceived content.
But a recent study by scientists has shown that this remedy is somewhat useful. The study was published in the May 9 issue of the journal PLOS Biology.
The researchers chose Aedesalbopictus as a research object. This is a mosquito from Southeast Asia. It is highly adaptable to the environment, so it has long been limited to Southeast Asia and is also found in China.
In addition, it is more aggressive than other mosquitoes and can spread unpleasant diseases (such as dengue fever, yellow fever and Zika virus), so it is the Invasive Species Expert Group of the IUCN Species Survival Commission ( ISSG) is listed as one of the world’s top 100 alien invasive species.
Maybe you know that only female mosquitoes will suck blood because they want to have a baby, but in fact they will also take the honey or sap of the flowers to get the sugar.
Because the researchers saw this, they felt that they could use the characteristics of mosquitoes like sugar to reduce their impulse to suck blood. So the researchers immediately experimented. They prepared some transparent plastic cups covered with nets, and put the mosquitoes in these cups. There was a cotton ball hanging in the cup. The cotton balls in some cups were soaked in sugar ( The concentration is 5%, 20%, 50%), and some are ordinary water, so it is convenient for comparison.
Source: Document 1
The mosquitoes were hungry, and the researchers experimented in the morning and afternoon, putting their hands on the plastic cup for 1 minute, trying to attract mosquitoes to bite him, but keeping a distance, not letting the mosquitoes really Sucking blood, like the following picture, constantly “tune” and “seduce” mosquitoes…
The researchers found that in the cups with pure water, female mosquitoes are more aggressive and attack more frequently; in cups with syrup, the aggressiveness of mosquitoes is much weakened, and the higher the concentration of sugar, the more The more energy, the more obvious the weakened aggression, which means that the syrup has the function of debuff, which will reduce the “impulse” of the mosquito to suck the blood.
Sugar water weakens the aggressiveness of mosquitoes, and the thicker the sugar, the more obvious the source: Document 1
Now there is another question. Which kind of syrup can be more effective in repelling mosquitoes? Is it sucrose, glucose or fructose?
To find out the answer to the question, the researchers used 20% sucrose, glucose, and fructose to do the same test.
Dark red fructose, light red sucrose, yellow glucose source: Document 1
It turns out that there is basically no difference in reducing the aggression. If it is more than one, the fructose effect may be better. As for why there is no difference, it is estimated that the heat provided by these kinds of sugars is almost the same.
The effect of three different sugars on mosquito bites: Source 1
Why do mosquitoes like to eat sugar?
Because it is sugar or blood, it can provide energy for the reproduction of female mosquitoes. If there is no sugar, then the mosquito can only suck blood, and sugar is just one of the options for a mosquito to eat. And under normal circumstances, the risk of eating sugar is almost zero, and blood-sucking may be shot by humans. If you are a mosquito, which one would you choose? Therefore, mosquitoes eat sugar is a choice for survival strategies.
The mosquito’s genes determine it all.
The researchers later sequenced the RNA (ribonucleic acid, a genetic information vector found in biological cells and some viruses and viroids). They found that some changes in gene expression are associated with decreased interest in smoking human blood. One of the genes is the yolk gene, called Vg-2, which plays a role in the ovarian development of female mosquitoes, and when they eat sugar, the gene is expressed more. That is to say, the higher the Vg-2 expression, the less the impulse of the mosquito to suck blood.
The researchers then conducted another experiment: they interfered with mosquito RNA and reduced Vg-2 expression. It turns out that although female mosquitoes only eat sugar, they still feel hungry in human blood. It is confirmed that Vg-2 and mosquito sucking blood are inextricably linked. In the future, it may be possible to use this technology to suppress the blood-sucking of mosquitoes and let them “reform the evils” so that the mosquitoes can only eat sugar and not suck blood.
Summer is here, everyone can try this scientific “prescription” at home! But remember to change the sugar simmer frequently. Scientists used sugar to induce the effect of suppressing mosquito bites for less than a week, because the concentration of sugar water is reduced. used. If you follow the scientist’s practice, the choice of sucrose as a material is ok, the higher the concentration of sugar water, the better. In addition, the use of syrup to repel mosquitoes seems to be only useful for young females. In other words, syrup does not work for those mosquitoes.