The meadow is home to a variety of organisms: the goshawk, the common starling, the common cress, red clover and the cabbage white butterfly. Which named organisms can be used to make up a food chain, compose it. Identify the second-order consumer in this chain. Select pairs of organisms that enter into competitive relationships with each other.

Answer

Food chain: common cress → cabbage white butterfly → common starling → goshawk. The second-order consumer is the common starling. Competitors include common cress and meadow clover.

The reservoir is home to a variety of organisms: perch, pike, single-celled green algae (chlorella), daphnia, and tadpoles. Make a food chain from the named organisms. Specify a third-order consumer. Select pairs of organisms that engage in predator-prey relationships.

Answer

Food chain: chlorella → daphnia → tadpoles → perch → pike. The third-order consumer is perch. Tadpoles and daphnia, perch and tadpoles, pike and perch enter into predator-prey relationships.

Make a food chain using all the named representatives: great tit, apple beetle, hawk, apple flowers. Identify the second-order consumer in the constructed chain.

Answer

Food chain: apple blossoms → apple beetle → great tit → hawk. The second-order consumer is the great tit.

Make a food chain using all of the following objects: humus, cross spider, hawk, great tit, housefly. Identify the third-order consumer in the constructed chain.

Answer

Food chain: humus → housefly → cross spider → great tit → hawk. The third-order consumer is the great tit.

1. The pasture food chain of biogeocenosis includes producers and consumers. 2. The first link in the food chain is producers. 3. Second-order consumers eat plant foods. 4. Producers in the dark phase of photosynthesis form ATP molecules. 5. Decomposers destroy organic substances formed only by consumers into inorganic ones.

Answer

3. Second-order consumers eat animal food (first-order consumers).
4. Producers form ATP in the light phase of photosynthesis, and in the dark phase they form glucose.
5. Decomposers destroy organic substances formed not only by consumers, but also by producers.

Find errors in the given text. Indicate the numbers of the sentences in which they are made, write the correct answer.
1. The food chain of biogeocenosis includes producers, consumers and decomposers. 2. The first link in the food chain is consumers. 3. Consumers in the light accumulate energy absorbed during photosynthesis. 4. In the dark phase of photosynthesis, oxygen is released. 5. Decomposers contribute to the release of energy accumulated by consumers and producers.

Answer

2. The first link in the food chain is producers.
3. Producers in the light accumulate energy acquired during photosynthesis.
4. In the dark phase of photosynthesis, oxygen is not released.

Why can granivorous birds at different periods of life (dispersal, reproduction) occupy the place of consumers of the first and second orders in food chains?

Answer

Granivorous birds themselves feed on grains (they are consumers of the first order), and their chicks are fed with insects (at this moment they are consumers of the second order).

Blood-sucking insects are common inhabitants of many biocenoses. Explain in what cases they occupy the position of consumers of the II, III and even IV orders in food chains.

Answer

A blood-sucking insect is a second-order consumer if it feeds on the blood of a first-order consumer (a herbivore, for example, a cow).
A blood-sucking insect is a consumer of the third order if it feeds on the blood of a consumer of the second order (a small predator, for example, a fox).
A blood-sucking insect is a fourth-order consumer if it feeds on the blood of a third-order consumer (a large predator, for example, a tiger).

Why are owls classified as second-order consumers in a forest ecosystem, and mice as first-order consumers?

Do you know all your neighbors? Sure? Some of them are so small that you simply can’t see them. Insects live in almost every home. This is a fact: even if you don’t see them, this almost always means that the “roommates” are simply hiding very successfully. In some cases, insects in an apartment are absolutely harmless, but some of their species pose a serious danger not only to food and things, but also to the person himself. In general, get acquainted!

For thousands of years, people have sought shelter, starting with the first cave, then building shelters from tree branches and leaves, and making tents from animal skins. As time passed and additional tools were developed, humanity began to build houses from strong wood and stone, and houses appeared. And always, from the very first home, various insects lived next to a person. Today we see them as uninvited guests and prefer to live without them. But if you think about it, they were before us, and they will be after us. For your consideration, here is a list of 15 small creatures with whom you may share your home. They are also called synanthropes (non-domesticated plants and microorganisms whose lifestyle is associated with humans and their homes, for example, cockroaches, house flies, house mice, bed bugs).

15. Spiders

Spiders are probably one of the most common creatures with which we share our homes, and some of these arachnids will appear on this list more than once. There is a great variety of spiders in nature, more than 45,000 different species. Overall, modern spiders have spread throughout the world over the past 200 million years, which is largely responsible for their wide distribution and diversity. The spider does not do anything bad in the house, sometimes it even does good - it catches flies. Our ancestors had a huge number of signs associated with spiders, mostly positive. They say spiders are harbingers of good things to come. But, probably, if you trust signs too much, you will be completely covered in cobwebs.

14. Ground beetles

Just like spiders, beetles are very ancient and well-adapted creatures for survival. There are more than 40,000 species of ground beetles alone in the world, and these insects come to our homes uninvited. The most common is the bread ground beetle. They usually cause damage to crops in fields, but are increasingly found in ordinary apartments. The bread ground beetle crawls into the apartment only if it likes the living conditions. As soon as the insect gets into the house, when darkness falls, it goes to look for food (crumbs, food left on the table, cereals). Ground beetles interfere with sleep, rustle, fall from the ceiling onto the bed or directly onto you. And if they have found food, then the next step will be their reproduction. So, if a ground beetle appears in the house, you need to take immediate action.

13. Crickets

The wise cricket who gave advice to Pinocchio probably looked something different. And ordinary crickets are creepy insects, sometimes of enormous size. A folk sign says that if there is a cricket in the house, then this is a sign of happiness and prosperity. But people who have been visited by this “happiness” in large numbers do not share this point of view and are looking for ways to get rid of them. About 2.3 thousand species of these insects are known in the world, of which only about 50 are found in Russia. Most of them live in subtropical and tropical countries. Our most famous species are the field cricket and the house cricket. The house cricket in the southern part of the country lives both in apartments and in nature. In the central and northern regions, it lives only in houses near people, and gives preference to old, warm rooms with high humidity. These insects live and breed well in warm basements flooded with water. Sometimes crickets can spoil food and even things in the apartment, just like moths. Therefore, although popular wisdom advises against offending them, it is better to remove the crickets. Unless, of course, you like the “night concerts” that crickets usually organize.

11. Carpet mite

Scientists have found more than 1,000 different species of house ticks, and all of them cause great harm to humans, all year round. Any carpet or carpet perfectly collects dust, it accumulates in its fibers and even daily cleaning will not give a positive result - dust and mites will still remain there. Ticks, unlike most insects on this list, are very harmful to humans. The ticks themselves are capable of leaving behind their waste products in the form of feces, which contain digestive enzymes, they destroy the cells of the human body and can cause severe allergies and asthma. The damage caused by carpet mites is not limited to allergies: conjunctivitis, allergic rhinitis, atypical dermatitis and others can develop. It’s easy to deal with them - throw away all carpets and upholstered furniture once and for all!

10. Dark-winged mosquito

The main harm is that they squeak and interfere with sleep! Thank God, humanity has invented many ways to get rid of mosquitoes. Mosquito nets, repellents and fumigators are a whole industry. Place fresh branches of elderberry, bird cherry, Caucasian chamomile or basil in the rooms, and place a container with tomato seedlings or geranium in a pot under the windows and on the balcony. Mosquitoes do not like the smell of these plants, so they will want to leave your home as soon as possible. According to folk superstitions, these small, disgustingly buzzing bloodsuckers - mosquitoes - are capable of bringing not only absolute harm, but also benefit, predicting the weather and future events. Clouds of mosquitoes mean good weather tomorrow. Painful mosquito bites and especially active buzzing of bloodsuckers - foretells imminent bad weather and night rain.

9. Spitting spider

As mentioned earlier, this list will feature more than one species of spider. Spiders of this species catch prey by spraying a liquid onto it, which neutralizes it by solidifying into a toxic and sticky mass upon contact. You can observe the habit of spiders swaying from side to side. They do this to wrap up their prey. Most spiders are only capable of producing silk, but Scytodes spitting spiders are an exception. Together with the silk, they release poison from their mouths, and silk strands soaked in the toxin, falling on the spider’s victim, bind it. These spiders are not dangerous to humans, do not weave large trap webs, and are unremarkable in appearance. But they still have one peculiarity - during the hunt they “spit” their prey. This may sound a little harsh, but it's accurate. This is why they got their name “spits”. Spitting spiders live in both warm tropical and temperate regions, including Russia - in human homes, where it is warm.

8. Clothes moth

Moths inhabit houses and are a household pest, whose caterpillars spoil fabrics by eating them and gnaw the silk upholstery of furniture. Only caterpillars cause damage to products, because adults lack gnawing type mouthparts. In the dark at night, adult moths fly towards an artificial light source. According to some data, house moth caterpillars also feed on substances of plant origin, namely grains of wheat, barley, oats, corn, flour and dry bread. House moths are widespread worldwide; this species of lepidoptera is a serious pest in human homes. They feed on clothing, carpets, blankets and upholstery, as well as fur, wool, feathers and miscellaneous items such as animal bristles used to make toothbrushes and piano fibers.

7. Woodlice

Generally speaking, woodlice are not insects (they are crustaceans), but they lead approximately the same lifestyle as cockroaches. When threatened, they curl up, simulating death.
In most cases, wood lice appear only in those apartments where it is constantly damp, for example, water leaks from pipes. These insects are excellent indicators of various plumbing breakdowns and depressurization of flanges. The appearance of woodlice in an apartment, first of all, should worry lovers of indoor flowers, because if measures are not taken in time and they are not removed, the plants will soon die. First of all, these insects harm moisture-loving tropical plants that have a thin and delicate root system (orchid, fern, cactus), affecting it specifically, so if you have just such plants, then you should fight more actively.

5. Ants

At different times of the year and in different regions of the country, in an apartment, and even more so in a private house, you can often find representatives of various species of ants. Very often, ants in an apartment are random guests, carried on clothes or with things. Among them there are insects of different sizes and colors. However, the only real pest in the apartment is the so-called pharaoh ant - an independent species of heat-loving small ants, which in our latitudes cannot live anywhere other than residential heated premises. These red ants in the apartment are a real problem: they are numerous, they spoil food, they can carry pathogens of various diseases, and besides, they are very difficult to remove.
One colony of house ants can contain several dozen queens and up to 350 thousand workers. The reasons why red ants appear in an apartment, although not numerous, can be found in almost any home. That is why small red ants are successfully conquering more and more new areas and are likely to appear in any apartment, even the cleanest one.

4. Serebryanka (common silverfish)

You may have once seen them in the bathroom or toilet if you went there in the middle of the night (when the light is turned on, they quickly run away). Those thin, silvery, small things on the floor? Do you remember? They are called silverfish. Like most of the other creatures on this list, silverfish pose no real harm to us and they don't bite. Cases of contact did not reveal any negative impact on human health. They feed on products of plant origin containing starch or polysaccharides; but they may not eat anything for months. Their diet may include sugar, flour, glue, book binding, paper, photographs, starchy fabrics. From storage areas they can be brought into the home through the purchase of toilet paper or cartons of paper napkins. They are harmless to humans and pets and are not carriers of diseases, but can damage damp paper.
Their scientific name is “common silverfish” (Latin: Lepisma saccharina). It is believed that the silverfish is one of the most ancient living insects - its ancestors lived on Earth more than 300 million years ago, back in the Paleozoic era. Silverfish prefer damp and dark places; if the house is dry and light, then there will be no silverfish there.

3. Cockroaches

The remains of cockroaches are, along with the remains of cockroaches, the most numerous traces of insects in Paleozoic deposits. Additionally, cockroaches are the earliest known Polyneoptera, possibly descending from the ancestor of the entire subcohort. They have always been and will be on Earth. There are more than 4,600 known species of cockroaches; are especially numerous in the tropics and subtropics. There are 55 species on the territory of the former USSR. In recent years, there have been popular reports about a decrease in the number of certain species of cockroaches in the CIS (they say they have completely left apartments in St. Petersburg and some other cities - no one was upset, but the reasons are interesting).
A number of cockroaches live in human dwellings, being synanthropes, for example, the red cockroach (Prusak), or the black cockroach. Others are brought with tropical products to temperate countries and sometimes take root in heated rooms (American cockroach). Cockroaches can damage food, leather goods, book bindings, indoor and greenhouse plants. Some cockroaches, feeding on various waste, including feces, are carriers of infectious diseases (for example, dysentery) and worm eggs.

2. Harvesting spider

Hay-making spiders that build trapping webs are ubiquitous. Hanging upside down on their jumbled, tangled, uneven web. Webs are built in dark, damp niches of caves, trees and under stones, in lairs abandoned by mammals, for example, in cellars and various buildings. In human homes, they love dry and warm places near windows. How dangerous are harvest spiders to humans? Suffice it to say that they spend the poison they have exclusively on their victims, inflicting a paralyzing bite on them. He is not enough for anything more. The main reason for declaring war on arachnids is arachnophobia. Some people cannot even stand them visually; for others, a creature that gets on their body causes panic. The problem is so serious that psychologists are working on it.

1. Flycatcher

The common flycatcher, also known as the house centipede, is often found in private houses and cottages, and is also found in apartments. Due to its significant size, repulsive appearance and high speed of movement, this insect, which suddenly appears in a house, often inspires horror in residents. But the house centipede is a peaceful and completely harmless insect. They usually appear in search of food from the street or from a neighboring apartment. If centipedes can find a constant source of food in the house, then there is a high probability of their appearance in this room. Centipedes are especially often found in private houses, settling in basements, basements and subfloors, from where they go out to hunt, moving around all rooms.

People who sincerely consider themselves superior beings have still not been able to get rid of a minor but serious problem. Blood-sucking insects ruined the lives of humanity several million years ago and continue to do so today. Even far from nature, in megacities, there are people who want to drink human blood. Some bloodsuckers left caves in order not to part with their favorite dish and turned into synanthropic species. They now breed not in caves, but in the basements of residential buildings and apartments.

Synanthropic bloodsuckers

Fleas

Small black insects with a flat body that can jump. The length of fleas is 1-3 mm. In Russia you can find 5 species of these blood-sucking insects:

Morphologically they differ very slightly from each other. They feed on the blood of any available mammal.

On a note!

Fleas are temporary bloodsuckers, since they only jump on the victim to drink blood. Of the entire population of insects living in an apartment, only 10% are on the victim.

Under natural conditions, fleas are active around the clock during the warm season. They breed in houses all year round. The usual lifespan of an imago is 2 months.

On a note!

Fleas can carry a significant number of infectious diseases.

Bedbugs

Synanthropic bloodsuckers. Bedbugs and pigeon bugs attack humans.

Bed

On a note!

The body of the bug is brown. The insect is “flattened” on top. This structure allows a hungry bug not to fear for its life. Insects that have eaten are much more vulnerable, and a person can even accidentally crush them.

Bedbugs are “suspected” of carrying blood-borne diseases. For example, hepatitis B.

Pigeon

Lice

On a note!

Scientists believe that the head and clothes are related species that separated quite recently by the standards of evolution.

These two insect species are very similar morphologically:

• long narrow body;
• elongated abdomen;
• the head is smaller than the cephalothorax;
• gray color of a hungry insect.

But their habitats are different: the head one lives only in the hair, the clothes one lives in the folds of clothes.

Pubic differs from the two previous types in the shape of the body. She is "round". The body of the pubic louse is very short. It widens towards the anterior end and tapers towards the posterior end. The body shape is more reminiscent of a crab, a forest bug. Her habitat:

• groin area;
• armpits;
• brows;
• eyelashes.

The pubic louse is not found in other areas of the human body unless it gets there by accident.

Nasty

In addition to synanthropes, there are bloodsuckers that have not left their natural habitat, although some of them can live in the city. Most of these insects are united by the concept of “gnus”. A collection of blood-sucking flying organisms called “gnus” – insects with two wings of different sizes, united only by the need to drink blood for reproduction. The totality of the gnat includes:

• horseflies;
• autumn fireweed;
• mosquitoes;
• midges;
• biting midges;
• mosquitoes;
• tsetse flies.

The very concept of “gnus” came from Siberia, where this word was used to describe small blood-sucking insects.

On a note!

Because of the midges in the taiga, people are forced to wear mosquito masks. But this doesn't help much. Midges find cracks and hide even under clothes.

Horseflies

The largest flying blood-sucking insects in Russia. These are flies that need to drink blood to reproduce. They live in forest, steppe and desert zones. Most species stay near water bodies, as the larvae develop in a humid environment. Only females drink blood. In addition to being painful, insects are dangerous because they carry infectious diseases. This family of bloodsuckers is active during the daytime. They prefer heat. In the early morning and at dusk they do not disturb the animals.

Autumn burner

A small fly, very similar to a house fly. Often these two types are confused. But the brownie is not a bloodsucker. A distinctive feature is that this insect drinks blood differently from other bloodsuckers. The zhigalka does not pierce the skin, but scrapes off the top layer and licks off the released liquid. At the same time, she releases poisonous saliva, which thins the blood.

On a note!

Livers are active during the day throughout the warm season. At the beginning of summer they are not noticed, since the number of these blood-sucking flies is still insignificant. In the fall, before hibernation, the multiplied population causes a lot of inconvenience to people.

Mosquito

Midge

Small dipterous insects that are part of the “gnus” group. The midge lives on all continents. Females are blood-sucking, males feed on nectar. They leave more swelling than mosquitoes. The midge does not pierce the skin, but cuts it. Saliva with anticoagulants is injected into the wound. Insects are active in calm weather at temperatures of 8-30°C. In windy weather they are blown away. Midges carry many diseases that are dangerous to humans.

Mokretsy

Very small insects are bloodsuckers that look like mosquitoes. They live everywhere except Antarctica. – the name of the family, not the species. There are genera in the family that feed only on nectar or are predators. There are also genera where the females are blood-sucking and the males are “vegetarians”. Females of blood-sucking species are included in the “gnus” group. Insects are capable of transmitting infectious diseases.

On a note!

An insect of the bloodsucker family. The second name is, in everyday life they are often called bloodsucking beetles. The species is very numerous in Russia, both in the European and Asian parts. Having found a host, the insect sheds its wings and remains to live on the animal. Due to the lack of wings, the bloodsucker is often confused with. Flies are similar to these arthropods not only in body color, but also in the tenacity of their legs.

Bloodsuckers rarely attack humans, but such cases do occur. The bites of bloodsucker and horsefly are comparable in pain.

The saliva of blood-sucking insects has anticoagulant properties and causes itching and local irritation of the skin. Some people may have severe allergic reactions to their stings.

Rice. 21.11. Fleas. A-human; B-rat; IN- stomach of a gopher flea blocked by plague bacteria

Most famous human fleaPulex imtans And rat fleaXenopsylla cheopis (Fig. 21.11, A, B). Both species prefer to feed on the blood of humans and rats, respectively, but also easily switch to other types of animals. The rat flea lives in rat burrows, and the human flea lives in floor cracks, behind baseboards and wallpaper. Here, females lay eggs, from which worm-like larvae develop, feeding on decaying organic matter, including the feces of adult fleas. After 3-4 weeks they pupate and turn into mature insects.

Fleas visit humans at night. Their bites are painful and cause severe itching. But the main significance of fleas is that they are carriers of bacteria - pathogens plague Plague bacteria, once in the flea's stomach, multiply there so intensively that they completely close its lumen. This condition is called plague block(Fig. 21.11, IN). If a flea begins to feed on a healthy animal or person, after piercing the skin, it first burps a bacterial lump into the wound, due to which a huge number of pathogens immediately enter the bloodstream.

The natural reservoir of plague are rodents - rats, gophers, marmots, etc. These animals suffer from a number of other infectious diseases: tularemia, rat typhus etc. Therefore, fleas are known as carriers of pathogens and these natural focal diseases. It is interesting that in addition to the transmissible method of infection with these diseases, there are other ways: through contact with infected animals, by drinking water from open reservoirs, etc., but with a flea bite, infection is the most likely, and the clinical picture is the most severe.

Struggle with fleas - keeping residential premises and outbuildings clean, using insecticides and various means of rodent control. Personal protective measures, such as repellents that are applied to clothing and bedding, also have an effect.

Order Hemiptera, or Bugs. A characteristic feature of bedbugs is the structure of their wings and mouthparts. The fore wings are highly chitinized in the proximal part, and transparent in the distal part. The piercing-sucking oral apparatus forms two channels. One of them serves to absorb liquid food, the second - to remove secretions from the salivary glands. Development with incomplete metamorphosis. Bed bugs have medical significance Cimex, Triatoma and some close to them.

Of undoubtedly greater interest are the South American kissing bugs from the genera Triatoma, Panstrongylus etc. (Fig. 21.12). These are large, up to 4 cm long, brightly colored insects that are nocturnal. During the day they hide in various shelters. They are specific carriers of the pathogen South American trypanosomiasis, or Chagas disease - TrypanosomaWithrAndzi. Infection of humans is facilitated by the ease of transition of bugs of this group from one host to another and such a biological feature as obligatory defecation immediately after a bite, which ensures that the invasive form of trypanosomes enters the bloodstream through the skin damaged by the proboscis of the bug.

Struggle with bedbugs comes down to improving living conditions, maintaining cleanliness and treating walls, furniture and other surfaces with long-acting contact poisons (chlorophos, metaphos, etc.).

Mosquitoes lay their eggs in water or on moist soil near water. Larvae and pupae lead an aquatic lifestyle and breathe atmospheric air using trachea. The larvae feed on tiny organic particles suspended in water. The most famous mosquitoes from the genera Culex And Aedes(non-malarial mosquitoes) - carriers of pathogens Japanese encephalitis, anthrax, yellow fever, and Anopheles(malaria mosquitoes) - specific vectors malarial plasmodium. It has been proven that the susceptibility of mosquitoes to infection with malaria pathogens is determined genotypically and is inherited monogenically. Malarial and non-malarial mosquitoes are easily distinguished from each other at all stages of their life cycle (Fig. 21.13).

Eggs of malaria mosquitoes. Anopheles are located on the surface of the water singly, and each is equipped with two air floats. Their larvae swim in a horizontal position under the surface of the water, and on the penultimate segment they have a pair of breathing holes. The pupae are shaped like commas, are, like the larvae, under the water surface and breathe air oxygen through breathing horns shaped like wide funnels. Adult malaria mosquitoes, sitting on objects, are located at an angle to their surface with their heads downwards. The mandibular palpi, located on both sides of the proboscis, are equal in length or slightly shorter.

Rice. 21.13. Mosquitoes at different stages of the life cycle.

A- Anopheles sp.;B- Culex sp.:

I - eggs, II - larvae. III - dolls, IV - imago; 1- air strikes, 2- egg raft, 3- breathing holes, 4- breathing siphon, 5-funnel breathing horns , 6- cylindrical respiratory horns, 7 - mandibular palps

Non-malarial mosquitoes pp.Culex and Aedes lay eggs that stick together in groups into small steel-gray rafts. The larvae are located under the surface of the water at an angle to it and have a long respiratory siphon on the penultimate segment. The respiratory horns of pupae have the shape of thin cylindrical tubes, and the mandibular palps of adult mosquitoes are short and reach no more than a third of the length of the proboscis. Non-malarial mosquitoes keep their bodies parallel to the surface on which they sit.

Fight with mosquitoes are most effective against the aquatic stages of the life cycle - larvae and pupae. Reclamation methods are used - filling ditches and quarries with standing water. It is possible to treat with pesticides individual reservoirs with a high concentration of larvae and pupae, as well as places of mass accumulation of mature stages of mosquitoes during the daytime (barns, barnyards). The most effective are biological control measures in combination with irrigation and drainage, carried out in accordance with state anti-malaria programs. Thus, in Western Transcaucasia, it was possible to quickly reduce the number of mosquitoes and the incidence of malaria in the population due to reclamation and breeding of fish - gambusia, which feed mainly on dipteran larvae. For personal protection repellents and mechanical means are used: gauze curtains, nets, etc.

Mosquitoes(family Phlebotomidae). Smaller insects 1.5-3.5 mm long, having a short proboscis, a strongly protruding thoracic part of the body in the form of a hump and abundant drooping of the body and wings with small bristles (Fig. 21.14, A).

Mosquitoes lay their eggs in rodent burrows and other shaded areas with a lot of organic matter and high humidity. The larvae develop for about 2 months and then pupate. Sexually mature stages appear after 10-12 days.

Rice. 21.14. Small blood-sucking dipterans.

A - mosquito; B - midge; IN - biting midge

Struggle with mosquitoes should be carried out comprehensively and aimed at the destruction of natural foci of leishmaniasis and other vector-borne diseases: this is the destruction of rodents and mosquito breeding sites, treatment of surfaces in outbuildings and dwellings with insecticides. Personal protection against bites is also effective.

Midges(family Simuliidae). Small blood-sucking insects 2-6 mm long. The mouthparts are short and very powerful, designed for piercing skin and licking blood. The wings are transparent, without spots, the limbs are short and thick (Fig. 21.14, B). Distributed everywhere, but they pose a particular danger in Africa and tropical America, where they are carriers of pathogens onchocerciasis. Interestingly, midges bite humans and animals mainly on the thighs and sides of the body. It is in these areas that Onchocercus microfilariae accumulate, which significantly increases the likelihood of their transmission.

Midges are found in large numbers near streams and rivers with fast flows, clean and cool water. At the bottom of such reservoirs, females lay eggs, from which larvae hatch, leading an attached and sedentary lifestyle. After 2-3 weeks, a pupa is formed, and after another 1 week, adult midges emerge from its shell. Their development proceeds synchronously, and a huge number of midges appear simultaneously over large areas.

One of the most environmentally friendly methods struggle with midges is the mechanical cleaning of areas of especially fast flow of rivers and streams, where midge larvae accumulate on the bottom and lying objects. At the same time, they are torn away from the place of attachment and carried away by the current. Many of them die or are eaten by various predators. In rare cases, in foci of onchocerciasis with a high concentration of midge larvae in small areas, the use of insecticides is possible.

Mokretsy(family Ceratopogonidae). The smallest of the blood-sucking dipterans. Their sizes range from 1 to 4 mm. Most species have spotted wings, long multi-segmented antennae and a piercing-sucking proboscis (Fig. 21.14, IN). They live everywhere, but just like midges, in the tropics they are carriers of pathogens of some filariasis.

Midges breed in small standing ponds or in moist soil. Development from egg to imaginal stage lasts about 1 month. A person is attacked mainly at high humidity or during rain. Personal protective equipment is most effective against biting midges.

Horseflies(family Tabanidae) - the largest blood-sucking dipterans, up to 30 mm long. The general appearance resembles large flies. The oral apparatus combines the features of piercing-sucking and licking.

Rice. 21.15. Large blood-sucking dipterans. A - horsefly Tabanus sp.;

B - horsefly Chrysophthalmus sp.; IN - autumn fly

The entire body of horse flies is covered with thin bristles (Fig. 21.15, A, B). Distributed everywhere. In northern latitudes they are carriers of pathogenic bacteria anthrax And tularemia, and in the tropics and filariae - pathogens loiasis. American horse flies bite humans and animals mainly on the head, where microfilariae are located. Horseflies are heat-loving and light-loving insects. They are active during hot daylight hours in the north only in summer, and in the tropics - in any season. People are usually attacked near water.

Female horse flies lay their eggs on semi-aquatic plants. The larvae develop in damp silt near the water's edge and lead a predatory lifestyle. The development cycle lasts on average about 1 year.

Personal protective equipment is effective against horsefly bites.

Real flies(family Muscidae). There are several blood-sucking species. Of interest are the autumn flies and tsetse flies.

Autumn burnerStomoxys calcitrans - a medium-sized gray fly with a boring proboscis (Fig. 21.15, IN). Both males and females feed on blood. The larvae develop in manure. In temperate latitudes, mass fly activity is observed in late summer and early autumn, and in the tropics - all year round. It usually lives near livestock farms and actively attacks both animals and humans. Is a mechanical carrier of pathogens tularemia And anthrax.

For fight against Due to the massive breeding of Zhigalkas, hygienic maintenance of domestic animals is necessary, and protection against bites is achieved by personal protective equipment.

Tse-tse flies.Glossina widespread in equatorial Africa. Quite large flies up to 13.5 mm long. The mouthparts are similar to the proboscis of the autumn fly (Fig. 21.15, IN). Females are viviparous, periodically giving birth to one larva, which immediately pupates, burrowing into the soil. After 3 weeks, the imaginal form appears. Reproduction occurs in the shade of trees and bushes on the banks of water bodies. Several closely related species of tsetse flies differ from each other in terms of coloration and, most importantly, biology: some species settle primarily near human dwellings and feed mainly on his blood and the blood of domestic animals. Others live in the natural environment (savannas and forests), preferring to feed on the blood of large wild ungulates, and bite humans by accident. All species are specific carriers of the pathogen African trypanosomiasis(see section 19.3.2). The main measure struggle is personal protection against bites.

Summer is the time for vacations, seaside holidays, interesting excursions and new experiences. But all this can be spoiled or even ruined. We are talking about insects that pester humans with their bites.
A rating of blood-sucking insects has been compiled, which includes:

1. Mosquitoes

The main pests and disruptors of sleep and peace. They belong to the Diptera family. They are distinguished by “graceful” forms. They have a thin body, long limbs and narrow, almost completely transparent wings.

Few people know that only female insects bite. The fact is that males lack a full-fledged jaw apparatus, and therefore do not bite.

Immediately after the bite, the female injects special substances with an anticoagulant effect into the coda. This prevents blood from clotting. It is the entry of saliva with such substances into the human body that almost immediately provokes itching, swelling, and hyperemia in the bite area.

The danger is that saliva can become a factor in the development of a severe allergic reaction for a person. In addition, infections are transmitted through saliva.

2. Horseflies

We are talking about large flies with fleshy proboscis. The proboscis inside has hard stilettos with a barbed-cutting mechanism of action. Thanks to them, the bite occurs.

Horseflies are quite dangerous organisms. They are carriers of many deadly diseases. In addition, the bites themselves are extremely painful and unpleasant. In addition to anticoagulants, horsefly toxins enter the body along with saliva. As a result, the wounds bleed for a long time, do not heal and hurt.

3. Gadflies

Representatives of small bloodsuckers (size - 1.5-6 mm). inhabit almost the entire globe, except Antarctica. The organisms are very dangerous because they carry dangerous diseases (leukocytozoonosis of birds, onchoercosis of livestock and humans).

After a midge bite, the swelling is much greater than after a mosquito. Therefore, pain and discomfort are also greater. The fact is that when attacked, insects are able to bite off part of the flesh (mosquitoes simply pierce the skin using thin mouth parts). Mica from midges is very allergenic, so it can provoke a severe reaction.

5. Woodlice

Females are a component of the midges. They belong to the Diptera family. Woodlice are constant carriers of dangerous pathologies, which in severe cases can cause the death of humans and animals.

In particular, insects carry: eastern equine encephalomyelitis, blue tongue disease, filariasis of livestock and humans. Often a severe allergic reaction occurs after a bite.

6. Ticks

7. Lice

The presence of suckers allows them to attach to their hosts. It is noted that a louse removed from a person - given a choice - will always return to him again. This is how affection is shown.
Lice are extremely small. Body length is up to 6 mm. There is a small head and chest, but a large abdomen.

Short antennae on the head of organisms are responsible for smell, its sensation and identification. Lice live relatively short lives. On average, their lifespan is up to 38 days. Reproduction occurs through the laying of nits. The female lays several hundred eggs, attaching them to hair or threads of clothing using an adhesive mass that she herself produces.

8. Fleas

Natural bloodsuckers with complete transformation. They often carry various pathogens that cause serious illnesses in humans and animals. Fleas have a well-developed but highly specialized oral apparatus, thanks to which the insect easily pierces the host's integument and sucks blood.

They often move by jumping, using the second and especially the third pair of legs for movement. The oral apparatus of fleas is spiny-sucking.

9. Bedbugs

The most common representatives of household bloodsuckers. They belong to the order Hemiptera. There is still no convincing evidence that bedbugs can transmit diseases.

But the harm they cause to humans does not decrease. Bedbugs bite strongly, depriving a person of sleep and rest. Thus, people’s ability to work is impaired and they become irritable. During an attack, the bug rarely sticks to one place. A distinctive feature of bedbug bites is the multiplicity of small skin lesions in the form of a “path.”

Insects have a flattened body up to 8 mm long. Males are usually much smaller than females. The color ranges from yellow to brown. There is a proboscis on the anterior edge of the head. It is with this that the bug pierces tissue and sucks blood.

The upper and lower jaws resemble undivided bristles and form 2 separate canals. One of them is used for receiving blood. The other is for salivation.

10. Bloodsuckers

Representatives of two-winged insects. They are found in all corners of the world (except Antarctica). Highly specialized blood-sucking organisms that infect only warm-blooded animals. The species is viviparous - females give birth to several mature larvae.

They have a fairly flat but wide body and tenacious limbs. Almost all types of insects do not have wings at all.

As you can see, there are many “vampires” who want to drink blood. Therefore, to prevent such situations before going on vacation, it is important to take care of safety: purchase repellents, remedies against allergies and inflammation.