Don’t you sometimes think that mosquitoes are looking specifically for you in order to manically bite you and make you deeply unhappy? But these bloodsuckers choose their victim based on a whole bunch of factors, and this is a story about the main “culprits” of a mosquito attack.
There are many myths about what repels mosquitoes
By the way, for those who don’t know, only female mosquitoes feed on blood. All males of all known species in the world feed on plant nectar.
There are many insects in nature, but mosquitoes are among the most annoying. They not only squeak, but also bite. It is believed that the male mosquito is not interested in blood. What then does he eat? Nectar, pollen? And why is blood so important to females? Why do they, neglecting the danger of being “slammed”, try to get enough of it from a person? So, mosquitoes: who bites, females or males? Let's try to figure it out.
These insects belong to the category Diptera, the long-whiskered group. In total, more than 3,000 species of mosquitoes are identified. They are divided into 30 genera. In our area you can find up to 100 varieties. What does a male mosquito look like?
He has a thin body: head, chest and abdomen. Most mosquitoes are no more than 15 mm in length. Their legs (three pairs) are long and with claws, and their wings are narrow with veins. The general color of insects can be gray, brown or yellow. Weight depends on the state of satiety and can range from 1 to 5 mg. The squeak is produced by the vibrations of the wings. Their frequency can reach up to 1000 beats per second in some species (usually from 500).
There are long sensitive antennas on the head. In males they are more “fluffy”. The oral apparatus consists of jaws and elongated upper and lower lips. They form a proboscis groove. Needles formed by underdeveloped jaws move along it. The cavity of the tongue serves as a channel for the passage of saliva containing anticoagulants and anesthetics.
Mosquitoes also have small teeth, which play an important role when piercing the skin of the victim. Females have piercing bristles on their proboscis, which males do not have.
The proboscis of males is more delicate. Due to the lack of piercing bristles, they cannot pierce the skin. What do male mosquitoes eat? Like many other insects, they feed on plant matter. Mainly carbohydrates: pollen and flower nectar. If a person hears a characteristic mosquito squeak, this does not mean that an insect capable of biting is nearby.
If the female, for various reasons, cannot find blood, she temporarily becomes a vegetarian. In this case, egg laying is impossible or significantly reduced. Protein and carbohydrate foods are processed in different parts of the digestive tract. If the female is “drinked” with a drop of blood, she will die. Protein food will end up in the wrong place. The section required for this purpose opens only when the skin is pierced.
It is believed that mosquitoes are selective when choosing a victim. If possible, they prefer the host's blood with a high content of cholesterol and testosterone. Some species of mosquitoes are particularly selective and look for victims among cold-blooded frogs, caterpillars and even fish.
On quiet summer evenings you can see mosquitoes swarming. These are all males, they are waiting for sexually mature females. When such an individual is nearby, its characteristic squeak at a certain frequency becomes audible to the males. They detect it with sensitive antennae.
The male mosquito, whose sensor tuning frequency matches the vibrations of the female’s wings, goes towards, catches her and holds her during mating. Fertilization is internal. The female develops eggs, which she lays on the surface of the water. They require blood to develop. Therefore, for a full and numerous clutch, the female is looking for an opportunity to get enough of it. The sensors on its antennae are sensitive to thermal radiation from the body of animals and humans. They can also sense their metabolic products from a distance: uric and lactic acid, carbon dioxide.
Urban mosquitoes can reproduce without swarming. This process often occurs in basements, pits and other nooks with limited space. What do male mosquitoes and mature females eat in such conditions? Decaying plant debris.
During its development, a mosquito goes through four stages. The larva hatches from the egg. Then it pupates and an adult is born. After saturation with blood, the eggs mature in the female’s body. Their laying occurs on the surface of the water: a puddle, a ditch, a pond, an artificial container. In one go, the female can lay up to 150 eggs. After a few days, depending on environmental conditions, the larvae will hatch. They live in the water column and feed on small plankton. From time to time they float to the surface to breathe.
During development, the larva molts four times and turns into a pupa. At this stage, the future mosquito can move more intensively in the water column. It floats to the surface and hides at the bottom in case of danger. After several days of development, the skin of the pupa located at the surface of the water bursts and a sexually mature mosquito appears through the resulting gap. It moves along the surface of the water to coastal vegetation. Males are born first. They wait for females and swarm near such places.
Mosquitoes can endure winter at any stage. Eggs remain viable even after 2 - 3 years in unfavorable conditions. Adults wait out the cold in tree hollows, under bark and other secluded places. In cities, they find refuge in damp basements, vegetable stores, and cellars.
A male mosquito lives half as long as a female. On average this is two to three weeks. Females can live up to three months or more. This is largely influenced by environmental conditions. As the temperature decreases, the period increases. Mosquitoes are of great importance in maintaining the natural balance of the ecosystem. They themselves and their larvae serve as food and are part of the food chains of larger species. Another role is that they can carry infections, and thereby regulate the number of animals susceptible to infection.
Mosquitoes can cause harm to humans. And this is not only skin irritation after their bites. Some types of mosquitoes can carry dangerous infectious agents: tularemia and arboviruses. Representatives of the genus Anopheles can be carriers of malarial plasmodia. They are contained in saliva and enter the human bloodstream when bitten. As a result, malaria may develop. In our region, this disease is rare and there is no point in worrying too much about it.
While male mosquitoes are not dangerous to humans, female mosquitoes can be a serious nuisance. It is believed that a healthy person is theoretically able to withstand up to 500 bites from these insects. A larger amount can cause death due to painful shock and intoxication. However, even a few stings can cause severe allergic reactions in some people.
To protect yourself, you should know that mosquitoes do not tolerate heat well and prefer to hunt in the shade or in the evening. They do not like windy weather and open areas of space, as they are easily blown away by air flow. It is better to protect your home with mosquito nets on the windows. Loose clothing significantly reduces the number of bites. Mosquitoes do not like the smell of anise, eucalyptus, wheatgrass, elderberry, lavender, and mint.
Excessive sweating makes a person more “attractive” and noticeable. Ultrasonic repellers that emit vibrations at waves that are “unpleasant” for insects, as well as fumigators that release chemical reagents, can help. Some drive away uninvited guests, others kill them. Topical application of repellents to the skin is also relevant.
Salicylic or boric alcohol, a solution of soda, vinegar, tea tree oil, and calendula tincture help to some extent relieve itching and swelling after bites. If you are predisposed to allergic reactions, it is better to have special antihistamines with you.
According to experts, approximately 20% of people are especially sensitive to mosquitoes
Intrusive insects constantly bite their victims. Despite the fact that scientists have not yet been able to develop a specific effective protection against intrusive insects, other than the use of special sprays (to which mosquitoes are gradually beginning to acquire immunity). Researchers claim that there are some reasons that explain the tendency of some people to get mosquito bites.
Blood type is important, since mosquitoes bite people to get protein from the blood. The results of one study suggest that under controlled conditions, mosquitoes are twice as likely to bite people with the first blood group than representatives of the second group. Carriers of the third blood group are also very popular with mosquitoes.
Based on the work of certain genes, approximately eighty-five percent of people through the skin can signal mosquitoes about their blood type, the remaining fifteen percent do not give such a reason to mosquitoes. It is not surprising that mosquitoes bite more those whose blood type they know.
One of the highlights, by which the insect finds its prey, lies in the smell of carbon dioxide produced by representatives of the human race when breathing. When searching for the most delicious blood, insects use an organ called the maxillary palp (a certain structure of the mouthparts), which helps mosquitoes find carbon dioxide even at a distance of fifty meters.
As a result, people who exhale significant amounts of carbon dioxide (mainly large people) are the most attractive to mosquitoes. This is why children are bitten by mosquitoes much less often than adults.
Exercise and metabolism play a big role for insects, because thanks to the smell of lactic acid, uric acid, ammonia and many other substances that are released along with sweat, they find their prey . The blood of people with a high body temperature is also very appetizing to mosquitoes. People who exercise a lot, thereby increasing the accumulation of lactic acid in their body and raising their body temperature, attract mosquitoes to their skin.
It is impossible not to take into account the role of genetic factors in influencing the amount of uric acid and other substances that are naturally released by each person, which also serves as a kind of tip for mosquitoes. In general, genetic factors account for eighty-five percent of human attractiveness to mosquitoes, regardless of whether factors such as blood type or metabolism are involved. However, at the moment, researchers do not have the ability to fully analyze these factors.
Based on other studies, certain types of bacteria living on human skin influence human attractiveness to insects. A study conducted by researchers two years ago found that the presence of significant numbers of certain types of bacteria on the skin attracts mosquitoes.
Interestingly, the places where the least amount of bacteria accumulates attract almost no insects, which is why mosquitoes love to bite people on the ankles and feet, because this is where the largest amount of bacteria accumulates.
Half liter bottle of beer turns a person into a potential victim of mosquitoes. Although scientists believed that this was due to an increase in ethanol excretion through sweat or an increase in body temperature, it is not directly related to the consumption of an alcoholic beverage.
Therefore, scientists are still thinking about why people who have drunk alcoholic beverages are much more attractive to mosquitoes than teetotalers.
In connection with numerous studies, scientists can confidently say that pregnant women are twice as likely to be attacked by mosquitoes, and all thanks to the symbiosis of two factors, since they exhale twenty-one percent more carbon dioxide, and the body temperature in pregnant women is much higher. higher.
According to James Day, a medical entomologist at Florida State University, insects can use sight (along with smell) to find their prey, which is why clothing in black, dark blue and red is more noticeable to intrusive insects.
According to many experts, natural repellents also play a serious role. Today, most experts are engaged in research into the reasons why some people are completely unattractive to insects in order to create the next generation of insect repellents.
By using chromatography to identify the essential substances that some people secrete, they are completely unattractive to mosquitoes. According to scientists from the Rothamsted Research Laboratory (UK), such people are carriers of natural repellers that secrete several substances that mosquitoes cannot tolerate.
As a result, by adding these substances to well-known mosquito sprays, you can save people with the first blood group, sports fans, pregnant women, and those who wear dark colors in clothes from the bites of annoying insects.
Now is the peak of the mosquito season, and while some lucky ones are not bothered by small insects, many are literally haunted by mosquitoes. Scientists are trying to understand what makes some people such attractive prey. Molecular biologist L.J. Zwiebel, professor of biology at Vanderbilt University, agreed to comment on this topic.
The sweet smell of success
Mosquitoes find their warm-blooded prey by capturing the heat and carbon dioxide that mammals exhale. Pregnant women and larger people are more likely to suffer because they expend more energy than the average person.
Mosquitoes are also guided by their sense of smell. “No matter what my grandmother said at the time, my blood is not sweet,” says Dr. Zwiebel. - Mosquitoes do not distinguish between the quality of blood. They are attracted to the human smell, which is largely generated by bacteria that live on our skin.” “The flora and fauna of our skin,” according to the biologist, smells delicious to mosquitoes, and when we sweat or spend a lot of time outside, this effect can be enhanced.
To the best of Dr. Zwiebel's knowledge, there is no scientific evidence to support online claims that insects are deterred by high cholesterol or diabetes. Taking vitamin B, garlic or special medications also does not help.
Immunity to bites
After working with biting insects for 20 years, Dr. Zwiebel now says he can stick his hand in a container of mosquitoes and be bitten hundreds of times and not show it. Children who have been bitten much less in their lives than adults may react more strongly to bites because their immune systems have not yet reached full maturity. However, adults who complain that mosquitoes prefer their blood are usually wrong. “Some people have more allergic reactions to stings than others, so they may appear to be bitten more often than others, even though they probably are not,” says Dr. Zwiebel.
What to do?
For those who have blisters and scratches all over their body, Dr. Zwibel advises not to itch in the first place. When a mosquito bites, its saliva remains in the wound, containing, among other things, anticoagulants and a local anesthetic. The body recognizes it as something foreign and sends histamines to counterattack. When we itch, we simply spread that saliva, promoting the production of antibodies, which only makes the itching worse. This is how it turns out to be a vicious circle.
For those whose skin becomes very swollen and itchy from bites, “you should talk to your doctor about taking an over-the-counter antihistamine every day preventatively,” says Dr. Zwiebel. You will still get bitten, but you may not even notice because the medications will prevent the allergic reaction that turns a painless bite into a serious nuisance.
The cleaner the better
Female mosquitoes bite us because they need to feed on blood to obtain proteins that allow them to complete their reproductive cycle and lay healthy eggs. To reduce the risk of being bitten, wash with antibacterial soap so that fewer bacteria that attract bloodsuckers live on your skin.
Other ways to avoid being bitten: Try not to leave the house between dawn and dusk, when mosquitoes are most active. Install an outdoor fan to keep insects away. Wear long pants and long-sleeved shirts unless it's too hot to do so. Dr. Zwiebel also recommends spraying clothing with a repellent that contains diethyltoluamide, a chemical that targets mosquitoes' olfactory receptors. “It works, and until we come up with anything better, this repellent is the most effective way to prevent bites,” he says.
InoSMI materials contain assessments exclusively of foreign media and do not reflect the position of the InoSMI editorial staff.
