TALLINN, June 8 - Sputnik. Scientists from the University of California in the United States filmed in detail the process of the absorption of human blood by a mosquito. A study on blood-sucking insects was published in the American edition of KQED.
Mosquito bites are much more dangerous to humans than any other animal bites, researchers say.
Scientists have found that the mosquito's mouth, called the proboscis, is not a single tiny "spear". It is a complex system of six thin needles, each of which pierces the skin, finds blood vessels and makes it easier for mosquitoes to absorb blood from them.
Insects have over 150 receptors on their antennae and proboscis that help them find prey or determine if there is enough nutrient water to lay eggs.
"Why do some people get bitten more than others?" asked Luckhart.
"The volatile fatty acids emitted by our skin are very different from person to person. They reflect differences between men and women, such as what we have eaten. It is not one or two, but a whole 'mixture' of signals that help insects make a choice," Luckhart explains.
However, scientists have not yet determined what specifically attracts mosquitoes most in some people. But what the researchers know for sure is that when an insect's proboscis touches human skin, one of the six needles, called a labrum, uses receptors on its tip to search for blood vessels.
"These receptors capture elements of the blood," says American University biochemist Walter Leal.
And vice versa, the elements contained in our blood, bouquets, reach the mosquito by smell, involuntarily showing him the way to the blood vessel. "Lip" only pierces the vessel and performs the function of a tube. Six needles simultaneously dig into the victim.
Two of them, the so-called maxillae or upper jaws, are equipped with many tiny needles, a kind of teeth, that penetrate the skin. Other "blades" or "drills" - mandibles - lower jaws - at this time hold the edges of the wound, preventing them from closing.
Scientists have been trying to figure out the anatomy of a mosquito bite for decades. In studying the nutritional system of these insects, they used powerful microscopes, genetic research and video recording capabilities.
When the mosquito's digestive tract fills with blood, the insect separates the red blood cells from the water in the blood, squeezing it out in the back of the body.
The sixth needle is called the hypopharynx, through which the mosquito lets saliva into the blood, containing certain substances that make the blood flow, they also cause itching after an insect bite.
"Your blood tends to coagulate immediately upon contact with air," Leal says.
Mosquito saliva also causes a person's blood vessels to dilate, blocks the immune response and lubricates the trunk, scientists explain.
The researchers concluded that some viruses originated only because of mosquitoes. This is not hard to believe, given that mosquitoes existed 200 million years before humans, the article notes.
"Because mosquitoes evolved the blood-drinking habit, some viruses followed that evolutionary path and became human-specific viruses carried by mosquitoes," said Shannon Bennett, a microbiologist at the California Academy of Sciences.
The science
Almost every one of us has encountered an annoying mosquito at least once in our lives, but few have seen what is actually happening up close.
French scientists conducted a study using microscope to see how mosquitoes feed on our blood from within. The video shows the mosquito using its long proboscis to find a blood vessel in a mouse.
Team led by Valerie Shumet(Valerie Choumet) from Pasteur Institute in Paris demonstrated how the malarial mosquito transmits pathogens.
Although at first glance the mosquito's proboscis looks like one long needle, its mouthparts actually consist of several sections that pierce the skin and penetrate inside. The proboscis itself is quite flexible, and not rigid, like a needle.
The video shows how the proboscis begins examine the layers of the skin to find a suitable blood vessel. The cube-shaped objects are skin cells, and the red tubules are blood vessels.
The mosquito in the video refers to the species Anopheles gambiae, and it bites a mouse, although the same thing happens when a person bites.
How to relieve itching from mosquito bites?
There are many mosquito bite remedies that help relieve swelling and itching.
Clean the bite immediately after the bite alcohol, wet wipes or plain water.
stick a piece adhesive tape on the bite and leave for a couple of hours, and then carefully remove it. This will help remove some of the itching saliva and speed up recovery.
Rub on the bite antiperspirant. The itching should stop almost immediately, as the aluminum salts help absorb fluid from the bite.
Attach baking soda paste and water to the bite
Try to rub wet bar of soap to the bite site and feel almost instant relief.
You can also lightly smear this place with a simple toothpaste.
A few drops lavender oil or tea tree oil reduce itching.
Allergy to mosquito bites
Most mosquito bites are fairly harmless, however they can sometimes cause severe swelling and redness. This allergic reaction is especially common in children.
Symptoms of allergy to mosquito bites include:
Large area of swelling and redness
Subfebrile body temperature
Enlarged lymph nodes
For a severe allergic reaction to a mosquito bite, the following are recommended: funds:
Take an antihistamine ( Zyrtec, Claritin)
Use an antipruritic agent ( Psilo Balm, Fenistil-gel) or apply ice for 10 minutes to the bite site
In case of an acute allergic reaction (anaphylaxis), you should immediately call an ambulance and inject epinephrine. If you know about the possibility of such a reaction, you should always carry the drug with you.
Mosquitoes have been constant companions of mankind since time immemorial. Now there are about 3,000 species of mosquitoes all over the world, of which more than a hundred can be found in Russia. But how much do we know about these insects, for example, what do we know about the structure of a mosquito?
How is the body of a mosquito
A mosquito is an insect with a thin body, up to 15 mm long, narrow wings and claws. Color - brown, yellow or gray. The body consists of a head, thoracic region and abdomen of ten segments. It is difficult to say how much a mosquito weighs, since basically the weight of an insect depends on the amount of food it has eaten.
However, on average, it is believed that a hungry mature mosquito by weight is 1-2 mg, a well-fed one is 3-5 mg.
The thoracic region is the central organ of the insect and bears the head, abdomen, wings and three pairs of legs. The chest of mosquitoes is divided into three parts: mesothorax, prothorax and metathorax, which are developed very unevenly. The external skeleton of the anterior chest is represented by 3 plates, due to which a rather long neck is formed.
The mesothorax is the most developed part of the thoracic region, but, like the prothorax, it consists of three plates. It is to the middle part of the chest that the anterior thoracic spiracle is attached. The metathorax under the microscope can be observed on the sides of the thoracic region.
Wings
The wings of mosquitoes consist of longitudinal and transverse veins, which are framed by a costal vein. They are covered with scales, an uneven accumulation of which forms light or dark spots on the body. A fringe is formed on the posterior edge of the wings with scales.
It is the wings that are what the mosquito squeaks. In flight, the insect waves them so fast that they are not visible at all, but only a thin squeak is heard. The oscillation frequency of the mosquito wings is up to 1000 times per second.
Many scientists believe that there are nerve endings on the outer covers of the wings, which are the sensory organs of insects.
Legs
The legs of mosquitoes consist of a coxa, trochanter, femur, tibia and tarsi. The tarsus is divided into five segments, the last of which has two claws. Under each of the claws there are suckers, of varying degrees of development in.
The main task of the claws is to keep the mosquito on overturned or vertical surfaces.
The parts of the legs that are close to the place of their attachment to the body are called the bases, and the parts that are most distant from the points of attachment are called the tops. The inner side of the apex of the hind tibia is represented by a row of flat spines that form a scraper.
Head
The head of these insects is characterized by features inherent only in their family. Firstly, fifteen-segmented antennae, and secondly, the structure of the food organs.
The oral apparatus of the mosquito is represented by the lower and upper lips and 2 pairs of jaws. The lips are elongated and form a groove, inside of which there are long needles formed by underdeveloped jaws.
Between the inner surface of the gutter and the tube, piercing stylets are placed, which have arisen from the upper, lower jaws and tongue. The cavity of the tongue serves to conduct saliva.
Many are interested in whether mosquitoes have teeth. There are, and moreover, in the puncture of the victim's skin, they play a major role.
The lower jaws, alternately working, clinging to the tissues with their teeth, contribute to the deepening of the antennae into the skin and facilitating the entry of all other piercing bristles. Mosquito teeth are very small, but they can even reach 50 in number. In females, the proboscis is long and consists of piercing setae; in males, there are no setae.
Only female mosquitoes feed on blood, while nectar is the main food for males. Females look for "donors", relying on high sensitivity to temperature, the smell of lactic acid and carbon dioxide. Moreover, they are able to capture the acid reserve released with sweat at a distance of up to fifty meters, body heat - up to thirty meters, and carbon dioxide - up to fifteen meters. During a bite, anticoagulants (prevent blood clotting) and anesthetics are injected into the blood of an animal or person by insects.
The abdomen of mosquitoes, as previously noted, consists of ten segments, the last two of which are parts of the external genital apparatus. Each of the anterior eight segments of the abdomen consists of dorsal and ventral plates, which are interconnected by a pleura - an unsegmented elastic membrane.
The increase in volume and stretching of the abdomen during bloodsucking, obesity and egg maturation lead to stretching and straightening of this membrane. In the pleura, each segment from the second to the sixth contains six pairs of spiracles, which differ significantly from the chest ones both in size and in structure.
The plates of the last segments form segments surrounding the genital and anus. Females also have short appendages at the end of the abdomen. The reproductive apparatus of males is arranged due to external appendages much more complicated.
The structure of immature mosquitoes
From the eggs laid by the female on the surface of the water, larvae hatch, which intensively feed and grow until pupation.
After leaving the egg and until the stage of maturation, the larva increases in volume by more than five hundred times, and in length by more than eight times.
Increased growth leads to the fact that the larvae undergo periodic molts, that is, they shed the old outer covers and form new, larger ones. During maturation, the larva goes through four larval instars.
Only hatched larvae are about 1 mm long, after the fourth molt - 8-10 mm. In addition to an increase in size, at each stage there is a complication of internal organization. After the completion of the fourth stage, a pupa appears.
At this stage, some of the internal organs are rebuilt, which leads to the formation of the organs of an adult mosquito. The completion of the development of an adult mosquito occurs with the release of the insect from the pupal skin.
Galileo. Mosquitoes: Video
Scientists have not been able to establish the first appearance of blood-sucking insects so far, although they found their remains during excavations. People who came across these pests noticed the presence of a proboscis, long legs and wings. A mosquito under a microscope has a completely different look, which scares and fascinates at the same time. If you use settings with multiple magnification, you can see all the details. And in this case, the person understands that the appearance of the insect is completely different.
What a blood-sucking mosquito looks like under a microscope can be seen in the images that are presented on the network. Looking at the pictures taken with the help of photographic equipment and a microscope, you can see that the body is covered with a small and dense bristle. This bristle is used by a blood-sucking insect to orient and search for certain objects, people. In an enlarged form, the head is also mesmerizing, because of which the mosquito seems to be an alien creature. The eyes are like a mosaic. They include a huge number of fragments connected into one whole.
The oral apparatus of a blood-sucking insect has a peculiar structure. The oral apparatus includes:
- Proboscis.
- Lower as well as upper lips.
- Jaws.
Not only the proboscis of a squeaking mosquito under a microscope, but also the nose resembles tentacles. The insect uses these tentacles to explore the area, as well as to search for blood vessels that are concentrated under the skin. If you look at the mouth apparatus, magnified 160 times, you can see the teeth of a mosquito. In total, the insect has 50 of them. Through small teeth, the blood-sucking pest is fixed.
If you examine the structure of the wings under a microscope, you can see small hairs on the outside. On the inside, transverse and longitudinal veins are dispersed in a certain order. The veins increase the rigidity of the wings. Therefore, mosquitoes easily move through the air, overcome various obstacles.
mosquito maturation
British scientists studied the life cycle of blood-sucking pests using a heavy-duty microscope. To do this, scientists prepared the larvae, launched the lamp. They observed all stages of molting, as well as features of the transformation of the pupa into adults. The worm that emerged from the larva has small wings, paws and a flexible proboscis. Imago gets out of the water and goes in search of food. Adult blood-sucking insects acquire the possibility of fertilization after 2–4 days. At the same time, females go in search of food sources, which they need for development and bearing offspring.
Bite in the details
The pest does not bite immediately. Before this, the pest picks up an area on the skin, under which a capillary or vein passes. If an insect experiences severe hunger, then it does not spend too much time searching. Through a microscope, scientists examine the meal. The network has pictures and videos with which you can understand how a squeaking mosquito bite occurs under a microscope. In the laboratory, scientists used a mouse for these purposes, although the scheme for other objects is no different. 
The video presented by scientists allows you to understand exactly how the search for a blood vessel under the skin occurs. For this, the insect uses the proboscis and nose. As soon as a suitable site is found, the pest pierces it with the help of the nose and starts feeding. The duration of the meal is 1-4 minutes. It takes 3 to 5 seconds to find a blood vessel. Since the mosquito sting is flexible, with its help the insect quickly finds the required area.
All the features and details that scientists managed to examine with a microscope are frightening and repulsive. People who have studied pictures of blood-sucking insects are trying to get rid of them using traps and aerosols, fumigators and other devices. Scientists note that such a structure is due to the need to search for food. If mosquitoes did not have tenacious paws or a proboscis, then they would not be able to find a blood vessel with the fluid they need.
Midges belong to the Diptera family of insects. The vast majority of species are part of the blood-sucking midge. There are over 1,500 varieties of midges in the world, about 300 are found on the territory of Russia. These insects inhabited all continents where there are places with flowing reservoirs.
General characteristics of the midge family
The international scientific name of the midge is Simuliidae, the closest relative is the twitching mosquito. These small insects, depending on the species, can have a size of 1 to 6 mm, the average life expectancy is about a month. The midge, like other representatives of the Diptera order, goes through four phases of development:
- Egg;
- Larva;
- chrysalis;
- Imago;
Females lay eggs in reservoirs: on stones, leaves, stems of plants. Individuals of some species even go down under water for this. Others prefer to drop their eggs on the fly. Usually, female midges gather in heaps and lay eggs together. At the bottom of such reservoirs, one can find places with large colonies of larvae. The larvae resemble tiny white worms that can only be seen under a microscope.
All phases of midge development, except adults, live in water. At the same time, a stagnant or musty pond does not suit them. These insects need flowing streams or rivers with fresh water and a fast current. The development cycle is usually 10-40 days, 4 offspring can mature over the summer. For the winter, midges leave in the phase of eggs or larvae.
Midges are malicious bloodsuckers that attack wild animals, birds, livestock and humans. Moreover, only females feed on blood, they need it for normal egg laying. Males of all species without exception feed on plant sap. There are species that do not need blood to go through the breeding cycle. But for those who need it, the number of eggs directly depends on the volume of sucked blood.
Midges attack during daylight hours, especially on a sunny hot day. In the northern latitudes, when the period of the polar day begins, midges are active around the clock. It has been noticed that the further north the habitat of these insects is, the more aggressive the midges are. For example, Odagmia ornata (decorated midge) in the tundra can become a real disaster for humans and animals, and closer to the south, in the forest-steppe and steppe zones, its attacks are almost invisible.
Mosquitoes, ticks, midges in the country, garden, vegetable garden and how to deal with them
Appearance and features of a midge bite
The appearance of midges is similar to small humpback mosquitoes. The color of the body, depending on the species, can be gray, black or dark blue. If we examine the midge under a microscope so that it is larger, it will be clearly visible:
- Short piercing-sucking proboscis;
- Rounded and large, bent to the lower surface of the chest, head;
- Complex compound eyes;
- Antennae, consisting of 9-11 segments;
- The organs of touch and smell are 4-segmented palps;
- Saccular abdomen of 9 segments, has the ability to stretch when eating;
- Short thick legs;
- Paws with claws at the ends;
- Wide and transparent wings;
Under a microscope, you can also see that the humpbacked chest of the midge is covered with hairs, sometimes there is a pattern in the form of silvery spots.
The bite of midges is different from the mosquito. Unlike a fellow that pierces the skin, the midge pinches off the top layer of the epidermis. This is facilitated by numerous teeth in the oral cavity, which can only be seen under a microscope. Immediately after the attack, she lubricates the bite with her saliva, which contains analgesic substances. That is why at first a person or an animal may not feel pain. The midge bites in places unprotected by clothing, and also crawls into the mouth, nose, ears, eyes.
The bite looks like redness, in the center of which a red dot is visible. Mosquito saliva is poisonous, if it enters the human body, it can cause local and general reactions, such as:
- severe itching;
- Strong burning sensation;
- swelling;
- hyperemia;
- Increased body temperature;
- tachycardia;
- The appearance of papules;
- Decreased blood pressure;
In rare cases, the bite causes anaphylactic shock. Midges attack en masse, sometimes such attacks even led to the loss of livestock, especially young animals.
Midges can become carriers of diseases, among them:
- Anthrax;
- Tularemia;
- Plague;
- Leprosy;
- Cholera;
The main species of the midge family
Midges can be divided into 2 ecological types:
- River;
- stream;
River midges in the bulk are active bloodsuckers, characterized by a long radius of dispersion and a large length of larval migrations. On the contrary, brook midges do not scatter far, and among this type there are quite a few blood-sucking insect species.
The most common types of midges on the planet are included in several subfamilies:
- The family of midges Parasimuliinae;
- The family of midges Prosimuliinae;
- The family of midges Simuliinae;
These insects are found in all parts of the world, except for Antarctica: in the taiga and forest zones, in the tundra. They attack the population of the USA and Canada, Africa and Latin America. In Russia, there are especially many of them in Siberia and the Far East, they also live in the mountainous regions of the Crimea and the Caucasus.
In the tundra, midges of the following types are especially annoying to people and animals:
- Creeping - Simulium repens;
- Decorated - Odagmia ognata;
- Broad-legged - Eusimulium latipes.
This type of midge causes significant harm to livestock. In livestock, as a result of attacks, weight gain decreases, milk yield decreases. With a mass attack on a person, a bite can cause poisoning.
There are so many of them that on a clear day, if a horde of midges obscures the sun, it will seem that twilight has come. The bite of the Colombian midge is dangerous - Simulium columbaczense, which lives in the Danube zone. This type of insect is a real disaster for livestock. Larvae begin to develop in the Danube and nearby rivers in early May, and by the end of the month huge swarms of midges are already observed. They attack animals in packs, which often leads the latter to death.
In the taiga, the most terrible species of midge is Kholodovsky's midge (Gnus cholodkovskii). Its bite is very painful, and the activity of insects does not disappear even after snow falls. In addition, another species of insects lives in the taiga - the tundra midge (Schoenbaueria pusilla), which is characterized by a seasonal outbreak. They attack at positive temperatures: from 6 ° to 20 °. A bite can cause a disease in a person - simulidotoxicosis, a special manifestation of allergies. However, any kind of midges can cause such troubles in the form of allergic reactions.
Fight against midges
To combat midges in nature, the best way is to exterminate colonies of larvae. Due to the peculiarities of the development of insects, namely the growth of offspring in water, the number of drugs possible to fight is significantly reduced. In this case, only microbiological agents can be used. These can be specially developed preparations for infecting a population of larvae with bacteria that are absolutely safe for other species of fauna.
Sometimes, to reduce the number of midges, fish are launched into the reservoir: ruff, roach, ide, grayling, which actively feast on midge larvae. Mechanical cleaning of reservoirs near settlements is carried out in order to reduce the number of midges.
Adult insects are exterminated with insecticides by treating vegetation.
A person, in order to prevent an insect bite, should follow a number of rules:
- Wear protective clothing that midges cannot bite through;
- Use repellents as protection;
- Use mosquito nets;
- Take into account the time of activity of midges;
A midge bite can provoke allergic reactions, itching and infection of the skin. That is why it is necessary to take all precautions to protect yourself from the attacks of these insects.
Video: How to deal with mosquitoes, midges and other midges in the taiga