Why do mosquitoes drink human blood. What do male mosquitoes eat? How to distinguish them from females? What types of mosquitoes are there in Novosibirsk

To begin with, tell me: did you think that a mosquito sucks blood through a tube? No matter how it is: the mosquito has not one tool, but a whole set - drills, pumps, syringes and fasteners.

In fact, the mosquito has not one, but six needles. At the ends of two of them are teeth with which the mosquito drills the skin. These instruments are so thin that a person hardly feels the bite. When a hole in the skin is made, the mosquito immerses a flexible needle-pump into it, which raises the blood up, while other needles serve as spacers at this time, expanding the hole.

Here's what it looks like on video:

And now back to our question.

If we are talking about the mosquito's own blood (hemolymph), then it performs the same functions as human blood - it carries nutrients, harmful metabolic products, hormones, and provides protection against infections. It does not tolerate oxygen and carbon dioxide only - the mosquito has a tracheal respiratory system, and oxygen is delivered directly to the cells through thin tracheal tubes. Larvae of ringing mosquitoes (“bloodworms”) are a rare case among insects when the hemolymph is colored red due to hemoglobin. These aquatic larvae breathe through the integument, their tracheae are poorly developed and do not open outwards with holes. They live in silt at the bottom of water bodies, where there is often very little oxygen, and hemoglobin allows you to bind and store additional amounts of oxygen. (See also the answer to the question "Do insects have blood?")

If we are talking about the blood that female mosquitoes drink when bloodsucking, then they need it primarily for reproduction. Females, like males, can drink water and nectar and live without blood nourishment. But most species and populations of kulicid mosquitoes (Culicidae; blood-sucking mosquitoes belong to this family) are not capable of reproduction without blood feeding. Blood, unlike nectar, is a food rich in proteins. The proteins contained in the plasma (the liquid part of the blood) and red blood cells are digested in the intestines of the mosquito, and the resulting amino acids are used to synthesize the proteins of its eggs.

3–4 days after hatching from pupae, female mosquitoes mate with males. Fertilized females are looking for their victims. Having drunk blood, females digest it within 2-3 days. During this time, eggs ripen in their ovaries, and then the female finds a suitable reservoir and lays her eggs on the surface of the water. A certain percentage of the females then die, and the survivors can drink blood again and only after that lay a new batch of eggs. (They do not need to mate again, as they retain sperm reserves in the seminal receptacles - a special section of the reproductive system.) The cycle "nutrition - digestion of food - laying eggs" is scientifically called "gonotrophic harmony".

But some mosquitoes don't need blood. For example, female large mosquitoes of the genus Toxorhynchites feed only on nectar. This is due to the nutrition of their larvae. The larvae of most mosquitoes eat bacteria and small particles of dead organic matter - detritus. And the larvae of Toxorhynchites eat the larvae of other mosquitoes - protein animal food. Therefore, they store enough protein in the larval stage to ensure that the female has enough to lay eggs, and she does not have to risk her life by extracting blood.

The ability to autogeny (laying eggs without bloodsucking) also appeared in the so-called "urban mosquitoes" - Culex pipiens pipiens forma molestus. Populations of these mosquitoes have adapted to life in the semi-flooded basements of city houses. Cellar water often contains enough organic matter that the larvae feed on, and the females of these mosquitoes can lay their first clutch of eggs without bloodsucking. For the next clutches, blood supply is needed, but the population can exist and increase in number indefinitely without it. Unfortunately, the "bloodsucking instinct" of the females of this mosquito has not disappeared, and they pester the inhabitants of some cities even in winter...

Answered by: Sergey Glagolev

If we are talking about the blood that female mosquitoes drink when bloodsucking, then they need it primarily for reproduction. Females, like males, can drink water and nectar and live without blood nourishment. But most species and populations of kulicid mosquitoes (Culicidae; blood-sucking mosquitoes belong to this family) are not capable of reproduction without blood feeding. Blood, unlike nectar, is a food rich in proteins. The proteins contained in the plasma (the liquid part of the blood) and red blood cells are digested in the intestines of the mosquito, and the resulting amino acids are used to synthesize the proteins of its eggs.

3–4 days after hatching from pupae, female mosquitoes mate with males. Fertilized females are looking for their victims. Having drunk blood, females digest it within 2-3 days. During this time, eggs ripen in their ovaries, and then the female finds a suitable reservoir and lays her eggs on the surface of the water. A certain percentage of the females then die, and the survivors can drink blood again and only after that lay a new batch of eggs. (They do not need to mate again, as they retain sperm reserves in the seminal receptacles - a special section of the reproductive system.) The cycle "nutrition - digestion of food - laying eggs" is scientifically called "gonotrophic harmony".

But some mosquitoes don't need blood. For example, female large mosquitoes of the genus Toxorhynchites they feed only on nectar. This is due to the nutrition of their larvae. The larvae of most mosquitoes eat bacteria and small particles of dead organic matter - detritus. And the larvae Toxorhynchites eat the larvae of other mosquitoes - protein animal food. Therefore, they store enough protein in the larval stage to ensure that the female has enough to lay eggs, and she does not have to risk her life by extracting blood.

The ability to autogeny (laying eggs without bloodsucking) also appeared in the so-called "urban mosquitoes" - Culex pipiens pipiens forma molestus. Populations of these mosquitoes have adapted to life in the semi-flooded basements of city houses. Cellar water often contains enough organic matter that the larvae feed on, and the females of these mosquitoes can lay their first clutch of eggs without bloodsucking. For the next clutches, blood supply is needed, but the population can exist and increase in number indefinitely without it. Unfortunately, the "bloodsucking instinct" of the females of this mosquito has not disappeared, and they pester the inhabitants of some cities even in winter...

Only females drink blood in humans, although for them it is not food in the usual sense of the word. In everyday life, they may well be satisfied with the usual "menu" of nectar and water. So why do mosquitoes drink blood? The thing is that many species and populations of the Culicidae family, including the blood-sucking mosquito, are simply not capable of reproduction without it.

They need proteins, which neither nectar nor even water can supply them with in the right amount. They are found in blood plasma and red blood cells. Once in the digestive system of the female, they are digested. As a result, amino acids are formed, on the basis of which the proteins of mosquito eggs are synthesized.

At the age of only a few days, it is time for the female to mate with the male. After fertilization, she needs to eat. She goes hunting, finds a victim and drinks blood. 2-3 days is the process of digestion. Meanwhile, maturing eggs grow in the ovaries. Then the insect looks for a reservoir and lays them on the surface of the water.

For the most "unlucky" this ritual is the last action in their life. But some, having gathered their strength, are able to go through the cycle again: find a victim, have a hearty lunch, find a reservoir and lay another batch of eggs. Scientists call this cycle “gonotrophic harmony.” At the same time, females do not need to mate again, since they have sperm reserves inside the spermatozoa.

Mosquitoes have a very interesting feature. It consists in the fact that the insect is able to recognize and select prey suitable for it from the general mass. Scientists have proven that the female can feel the heat, moisture and carbon dioxide released by people when they exhale. After analyzing the data, she knows whether this individual will fit as a victim or not.

Vegetarian mosquitoes

There are also species that do not need to hunt anyone. Indeed, why do mosquitoes drink blood when they can get the necessary proteins just by eating a neighbor? This is exactly what the larvae of the large insect of the genus Toxorhynchites do. Thanks to this nutrition of their cubs, females can limit themselves to a noble nectar diet. And the larvae, instead of eating bacteria and small particles of dead organic matter, dine on the embryos of other mosquitoes, thus replenishing the necessary protein reserves.

Urban mosquitoes are a special species. In scientific language, it is called Culex pipiens pipiens forma molestus. It is also capable of autogeny, that is, the laying of eggs without the use of someone else's blood. It lives in close proximity to people, most often in damp basements of houses. The water there often contains a large amount of organic matter, which is enough for the female in order to make the first laying of eggs. For subsequent cycles, bloodsucking is already necessary, but this species may well do without it. Unfortunately, the mosquitoes themselves do not know this and regularly pester people with their annoying attempts to satisfy their hunger. But they do this not out of bloodthirstiness and not from evil, but only because it is necessary for the maturation of offspring and procreation.

Surely many people think that the mosquito feeds on blood. That is why he so violently attacks people and tries to pierce them with his proboscis. This is not true. How not entirely accurate about the proboscis. He has a whole set there - drills, pumps, syringes and mounting structures. Let's talk about all this in more detail ...

Did you think mosquito sucks blood through a tube? No matter how it is: the mosquito has not one tool, but a whole set - drills, pumps, syringes and fasteners.

In fact, the mosquito has not one, but six needles. At the ends of two of them are teeth with which the mosquito drills the skin. These instruments are so thin that a person hardly feels the bite. When a hole in the skin is made, the mosquito immerses a flexible needle-pump into it, which raises the blood up, while other needles serve as spacers at this time, expanding the hole.

Here's what it looks like on video:

Through one of the needles, the mosquito, as if with a syringe, injects an anticoagulant that prevents blood from clotting and facilitates its pumping. It is at this moment that we feel the burning sensation.

Why does a mosquito drink blood?

If we are talking about the mosquito's own blood (hemolymph), then it performs the same functions as human blood - it carries nutrients, harmful metabolic products, hormones, and provides protection against infections. It does not tolerate oxygen and carbon dioxide only - the mosquito has a tracheal respiratory system, and oxygen is delivered directly to the cells through thin tracheal tubes. Larvae of ringing mosquitoes (“bloodworms”) are a rare case among insects when the hemolymph is colored red due to hemoglobin. These aquatic larvae breathe through the integument, their tracheae are poorly developed and do not open outwards with holes. They live in silt at the bottom of water bodies, where there is often very little oxygen, and hemoglobin allows you to bind and store additional amounts of oxygen. (See also the answer to the question "Do insects have blood?")

If we are talking about the blood that female mosquitoes drink when bloodsucking, then they need it primarily for reproduction. Females, like males, can drink water and nectar and live without blood nourishment. But most species and populations of kulicid mosquitoes (Culicidae; blood-sucking mosquitoes belong to this family) are not capable of reproduction without blood feeding. Blood, unlike nectar, is a food rich in proteins. The proteins contained in the plasma (the liquid part of the blood) and red blood cells are digested in the intestines of the mosquito, and the resulting amino acids are used to synthesize the proteins of its eggs.

3–4 days after hatching from pupae, female mosquitoes mate with males. Fertilized females are looking for their victims. Having drunk blood, females digest it within 2-3 days. During this time, eggs ripen in their ovaries, and then the female finds a suitable reservoir and lays her eggs on the surface of the water. A certain percentage of the females then die, and the survivors can drink blood again and only after that lay a new batch of eggs. (They do not need to mate again, as they retain sperm reserves in the seminal receptacles - a special section of the reproductive system.) The cycle "nutrition - digestion of food - laying eggs" is scientifically called "gonotrophic harmony".

But some mosquitoes don't need blood. For example, female large mosquitoes of the genus Toxorhynchites feed only on nectar. This is due to the nutrition of their larvae. The larvae of most mosquitoes eat bacteria and small particles of dead organic matter - detritus. And the larvae of Toxorhynchites eat the larvae of other mosquitoes - protein animal food. Therefore, they store enough protein in the larval stage to ensure that the female has enough to lay eggs, and she does not have to risk her life by extracting blood.

The ability to autogeny (laying eggs without bloodsucking) also appeared in the so-called "urban mosquitoes" - Culex pipiens pipiens forma molestus. Populations of these mosquitoes have adapted to life in the semi-flooded basements of city houses. Cellar water often contains enough organic matter that the larvae feed on, and the females of these mosquitoes can lay their first clutch of eggs without bloodsucking. For the next clutches, blood supply is needed, but the population can exist and increase in number indefinitely without it. Unfortunately, the "bloodsucking instinct" of the females of this mosquito has not disappeared, and they pester the inhabitants of some cities even in winter ...

Did you think mosquito sucks blood through a tube? No matter how it is: the mosquito has not one tool, but a whole set - drills, pumps, syringes and fasteners.

In fact, the mosquito has not one, but six needles. At the ends of two of them are teeth with which the mosquito drills the skin. These instruments are so thin that a person hardly feels the bite. When a hole in the skin is made, the mosquito immerses a flexible needle-pump into it, which raises the blood up, while other needles serve as spacers at this time, expanding the hole.

Here's what it looks like on video:

Through one of the needles, the mosquito, as if with a syringe, injects an anticoagulant that prevents blood from clotting and facilitates its pumping. It is at this moment that we feel the burning sensation.

Why does a mosquito drink blood?

There is nothing surprising in the chilling fact that the basis of the diet of some animals is blood (it is rich in nutrients, especially proteins). And there is nothing strange in the fact that some animals, in particular representatives of the Culicidae family, which we call mosquitoes, have adapted to get it.

Thanks to the “bloody diet”, female mosquitoes were able to lay eggs more than once in their lives, like many other Diptera, but several. A record number of clutches - 12 - was registered in a malarial mosquito. It is no accident that only female mosquitoes need blood - males are indifferent to it, they suck nectar and pollen from plants. There are almost no proteins, but enough carbohydrates as an energy source. However, females also switch to a vegetarian diet if there is nowhere to take blood, only in this case they cannot lay eggs.

In the family, which has about three thousand species, different taste preferences. Some mosquitoes specialize in one kind of host, others do not care who they bite - as long as there is plenty of food. There are also gourmets, lovers of cold frog blood. Even insects have been described attacking fish - mudskippers traveling on land. Some tropical species are able to feed on caterpillar lymph. But most still prefer the warm blood of birds and mammals.

To find a suitable prey mosquitoes help sensors on the antennae, which are sensitive to thermal radiation emanating from a living creature, as well as to its metabolic products: carbon dioxide and uric acid. Since there are two antennae, they point the direction to the source of blood very accurately.

The emergence and growth of megacities contributed to the emergence of new forms of mosquitoes that specialized in feeding on human blood, for example, the urban peeping mosquito Culex pipiens pipiens form molestus. It has recently been established that a female urban mosquito produces about 40 eggs from one milligram of human blood, and twice as many from the same amount of bird blood. This means that the process of adaptation is only at the very beginning.

It is curious that the larvae of urban mosquitoes, feasting in damp cellars on decaying organic matter, gain enough supplies to lay the first clutch of eggs without additional blood supply. Annoy us at night with bites and squeaks they go after that. This feature allows urban mosquitoes to sustainably maintain numbers, regardless of the availability of warm-blooded prey.