Insects are consumers of plants. The vast majority of insects feed on plant foods, many of them - leaves, stems, roots, flowers of living plants. Are all these insects pests? No, not all. On the contrary, paradoxically, almost all insects - consumers of plants, with a few exceptions, are useful, as they are an indispensable link in the cycle of substances in nature.
By way of comparison, such an analogy is appropriate. Man has long been using domestic animals that eat plant foods - grass and hay, but for people, these animals serve as a source of high-calorie proteins and fats. Insects in nature have a similar function, as they process plant tissues into fats and proteins of their body, and themselves, in turn, serve as an indispensable source of food for many predatory animals (they are especially important for insectivorous birds, small reptiles, such as lizards, amphibians, such as frogs). , etc.). This is the global significance of herbivorous insects, since without them many vertebrates and invertebrates would not be able to exist today.
The question arises; what kind of insects - consumers of plants are pests? Very few, mainly those that are able to periodically multiply in mass quantities and during these periods very intensively destroy vegetation, as is typical, for example, for locusts. Pests of agricultural crops, gardens and forests are especially dangerous during these periods. The vast majority of insects do not give such outbreaks of mass reproduction, and the damage that they cause to plants is easily compensated by these plants. From a practical point of view, these species cannot be considered harmful.
A correct understanding of these complex interactions of phytophagous insects with vegetation is very important for substantiating modern principles nature conservation.
Insects are plant pollinators. This is a classic example positive value insects in nature and on agricultural land.
The importance of bees, in particular the domestic bee, is well known for pollinating orchards, sowing fodder leguminous grasses for seeds, etc. The example of acclimatization of bumblebees in New Zealand is also indicative, where crops of red clover imported there did not produce seeds due to the lack of insects capable of pollinate this plant.
Pollinators are not only bees and bumblebees, although these representatives of the order Hymenoptera are the main visitors to flowers. In fact, all insects that actively visit plant flowers, be it butterflies, beetles, flies, etc., to one degree or another transfer pollen adhering to their body from flower to flower, and thereby contribute to pollination.
Without insect pollinators, a huge number of plants would be doomed to extinction, since the seed formation process would be disrupted.
Insects are soil formers and nurses. It is well known that more or less loose soil enriched with decomposing organic matter has the greatest fertility. That is why agricultural fields are plowed before sowing, while the soil is loosened, fertilizers are applied to it, including organic ones, which are of particular value.
In nature, on a huge scale, loosening of the soil and the introduction of decaying organic matter into its thickness are carried out by invertebrate animals. The useful activity of earthworms is especially known. Insects living in the soil also make a significant contribution to increasing its fertility. Previously it was mentioned positive influence on the soil of ants, which loosen it, constructing the underground part of the nest, and bring various particles of plants, i.e., decaying organic substances, into the soil. Numerous insects, intensively processing fallen leaves, quickly return the organic and mineral substances lost by it to the soil.
The excrement of vertebrates is immediately populated by insects, which either feed on them (fly larvae) or bury them in the soil, constructing special minks for this, and later use them as food for their offspring (dung beetles). It should again be noted that Australian pastures, overloaded with the excrement of grazing sheep and other domestic animals, were cleared of manure thanks to the active activity of dung beetles, specially acclimatized for this purpose in Australia.
The same groups of insects (flies and beetles) attack the corpses of animals and destroy them very quickly, leaving only the dried remains of the skin and skeleton.
Excrement of animals and their corpses are often breeding grounds for pathogens. Therefore, insects that destroy these remains are considered especially useful orderlies.
Nevertheless, it should not be forgotten that the significance of insects in contact with carrion and excrement is twofold: the rapid destruction of garbage is an example of their useful activity, however, these same insects, flying into settlements can spread pathogens.
Insects - pests of agriculture and forestry. In some years, characterized by mass reproduction of one pest or another, the resulting losses in crop yields can be very significant.
All organs of the plant are affected by pests: roots, stems, leaves, flowers and seeds. There are monophagous pests that feed on only one type of plant. Especially dangerous are the so-called polyphagous pests that can damage a wide variety of cultivated plants. Most types of agricultural pests have moved to crops from wild plants- after all, on crops, the living conditions for pests are more favorable: there is plenty of food and a fodder plant in monoculture conditions, when only this one species is sown, it is not necessary to look for it.
A special group of pests are insects imported from other countries. If these species find favorable conditions for themselves in new areas, they are able to breed in huge quantities. A typical example imported species is the Colorado potato beetle, which came to Europe from North America. No less dangerous agricultural pest - corn borer - was brought from Europe to North America where it became the scourge of corn crops. There are many such examples.
In total, the list of agricultural pests includes about 700 species of insects, of which about 50 are serious.
In the forests, outbreaks of mass reproduction of pests are also noted. These include primarily some butterflies, such as the Siberian silkworm, and beetles, such as bark beetles and woodcutters.
A group of needle- and leaf-eating pests weaken trees by eating assimilating organs, and quite often the needles and foliage are completely destroyed. Damaged stands slow down growth, and with repeated attacks of the pest, they can die.
Weakened trees are attacked by stem pests, which make passages in the thickness of the bark and wood that serve them as food. Stem pests not only finally lead the tree to death, but also spoil the wood, reducing its value.
The extermination of pests on agricultural crops and in forests is currently carried out mainly chemical method- dusting or spraying gardens, fields, vegetable gardens and individual parts of the forest with pesticides (insecticides). Getting on the surface of the body of an insect or along with food in its intestines, the insecticide poisons the pest, which dies.
However, as already noted, pesticides pollute environment, with repeated use, accumulate in plant and animal tissues and can ultimately damage human health.
Therefore, it is important to solve the problem of extermination of pests in the near future by methods that are safe for humans and animals, as well as without hazardous pollution environment.
The most promising in this regard is the use of substances of plant origin against insects, from which insects die; animals and humans are usually immune to these substances. One of these substances - pyrethrum - has long been known and is used against insect pests.
Of particular interest is the use of synthetic hormones to suppress harmful insects - substances that enter the body of an insect in the smallest doses, disrupt the normal processes of its growth and development, as a result of which the pests die.
It should also be emphasized that high agricultural technology (especially the destruction of weeds) limits the survival of pests and reduces their numbers. Therefore, with all pest control systems good agricultural technology refers to universal preventive measures.
Periodically 2 - 3 times a day, lice Feed on blood, piercing the skin with a sharp proboscis, which is usually drawn into the head, but when sucking blood, it moves out. proboscis has complex structure and consists of three needle-shaped stylets used to pierce the skin, and a suction apparatus.
The louse lives 30 - 45 days. The female lays eggs by attaching them to her hair or clothing. For the entire breeding period, on average, she lays 300 eggs. The larvae also feed on blood and reach maturity in 15 days.
If a louse that fed on the blood of a person with typhus gets on a healthy person, then it infects him not as a result of bloodsucking, but by excreting feces on his body and underwear, which contain pathogens. Through damaged skin or in contact with the mucous membranes of the nose, mouth and eyes, the pathogens of typhus and relapsing fever penetrate the human body, and a serious illness develops rapidly.
Unlike lice, fleas are less closely related to their host. For laying eggs, they move to various places littered with debris, use contaminated floor cracks, sawdust, and rags.
Flea larvae live in garbage and, unlike adult bloodsucking fleas, feed on various rotting residues.
Fleas are insects with complete transformation, having in life cycle pupal phase. Flea development is usually slow: the larva lives for more than 3 months, and the pupal phase can last more than 7 months. At favorable conditions temperature and humidity, development accelerates and a new generation of fleas appears after 3 - 4 weeks. Adult fleas live up to 1.5 years.
Plague is a disease predominantly of rodents, in whose burrows fleas breed in large numbers. AT natural conditions it is associated mainly with gophers and marmots, in cities - with rats. If a flea has sucked the blood of a sick rodent, it can transmit the plague pathogen to humans and domestic animals during subsequent bloodsucking. Especially dangerous are rat, dog, cat and human fleas.
Of serious medical and veterinary importance is the complex of blood-sucking Diptera, united by the name "gnus".
The main components of midges in all natural areas of the country from the tundra to deserts are blood-sucking mosquitoes, which are joined by midges, horseflies and midges. The midges are especially harmful in the Siberian taiga and Far Eastern mixed forests. In addition to the damage caused to humans and animals as a result of a mass attack of bloodsuckers, it should be borne in mind that some Diptera, which are part of the midges, can transmit pathogens of various diseases, including such serious diseases as malaria, anthrax, tularemia, etc.
Insects - pests of food stocks. Of this group of insects, beetles and butterflies are especially harmful, breeding in grain and products of its processing, most often in flour.
The larvae of the bread grinder beetle have a characteristic C-shape. They make passages in grain and breadcrumbs, live in lumps in flour. The development of the larvae of this beetle lasts up to 3 months. Grain and flour populated by a bread grinder are harmful to human health.
No less dangerous in granaries is the barn weevil - a beetle that is distinguished by its head elongated into a long tube. Its thick whitish larva develops inside grains of wheat and other cereals. The development of one generation of weevil is completed in 1.5 months, so its number in warehouses is growing rapidly. Flour from grain damaged by the weevil is not good for food.
In stocks of flour in warehouses and at home, dark brown flat oblong beetles often appear, which have a specific smell. These are flour bugs. Their larvae live in flour. If the flour is sifted, then the larvae remain on the sieve. The flour populated by the pest darkens, acquires an unpleasant odor and is not recommended for food.
Among the butterflies there are also serious pests of grain and flour. Barn moth caterpillars live in flour in silky tubes, polluting it with excrement. Flour is held together by silk threads into lumps, rots and loses its baking qualities.
Domesticated insects. Some species of insects have long been bred by humans in order to obtain honey, wax, silk, a number of medicinal and other useful substances. Like pets that can no longer live in vivo, some domesticated insects, such as the silkworm, are also no longer found in natural communities.
Of the other insects that man breeds in order to obtain valuable products, we should mention worms - a group related to aphids. Valuable natural paints, such as carmine, are made from worms, substances used in electrical engineering as insulators are obtained, etc.
Insects and aesthetic education. Many large and beautiful insects, primarily butterflies and beetles, like the bright and attractive flowers of plants, adorn nature, evoke a sense of admiration in humans and encourage us to take care of all the animals and plants around us.
Meanwhile, it was large and beautiful insects that for a long time served as an object of intensive collecting, exchange and even sale, which in principle contradicts the tasks of aesthetic education. Modern approaches to the protection of nature and the relevant legislation excludes the irresponsible extermination of insects, except for cases caused by industrial necessity or scientific tasks.
Insects should be collected without removing them from nature. the best way for this is photography, especially color.
Many http://casinosafetyinspector.com are designed to feel and look like the old mechanical models.
Among the insects, there are only two types of domestic ones - the honey bee and the silkworm.
Silkworm
One of the most mysterious stories is connected with domestication silkworm. The wild silkworm is a small nondescript gray moth living in countries Far East. Like all butterflies, silkworm caterpillars actively feed, and only on mulberry or mulberry leaves. Before turning into a chrysalis, the caterpillars wrap themselves with the thinnest thread, forming a cocoon. This thread is silk. In some places, wild silkworm cocoons are still being harvested, although both in quality and quantity, "wild" silk is much inferior to "domestic" silk.
The ancient Chinese were the first to learn how to breed silkworms, and this happened a very long time ago, about 5000 years ago. During this time, the silkworm has become a real pet, and it has changed so much that it is even considered a separate species. For thirty centuries, the Chinese have kept the secret of their wonderful silk. They have achieved a high skill in the manufacture of silk fabrics and did not want to share their secrets with anyone. Already in the VI century BC, there was the Great Silk Road, along which silk was transported from China, through Central Asia and Persia, further to Europe. The silk trade has played a very significant role in the history of the peoples of China and neighboring countries.
How does a silkworm caterpillar “make” silk? Under the lower lip she has a small tubercle, from the opening of which a sticky substance is released. When exposed to air, it hardens and turns into silk. It is with this thread that the caterpillar entangles itself, turning into a chrysalis. The entire cocoon consists of a single thread with a length of 300 to 3000 meters. This thread is very thin - 13-14 microns in diameter, but strong - it can withstand a load of 15 grams. There are cocoons different colors- silvery, golden, pinkish, greenish, blue.
Domestic silkworms are completely dependent on humans, they cannot live on their own. The domestic silkworm feeds in the same way as the wild one - only on the leaves of the mulberry tree.
The domestic bee is descended from the wild honey bee. Exact date its domestication is unknown, but already 3000 years ago in Ancient Egypt beekeeping was well developed. The oldest image of a bee was found on the rock of the Aran cave in Spain. The drawing, which shows people taking out honeycombs from a hollow, is 15,000 years old.
In the mythology and folklore of many peoples of the world, the bee plays a very important role. In temperate countries, the bee personified the awakening of spring. In Russia, there was even a special bee holiday - April 17th. many peoples, the image of the bee was associated with the theme of death and rebirth - this can also be found in ancient Greek myths, and in the Bible, and in African fairy tales.
Beekeeping has gone through several stages in its development. At first, people simply collected honey from wild bees in hollows. Often, in this case, the hollows were completely ruined, and the bees died. Then people began to capture swarms of bees and place them in natural and specially prepared hollows, hollowed logs or special hives made from clay or tree bark. To take honey and wax, the bees were killed with sulfuric smoke, and the hives were broken. Real beekeeping, close to modern, began to develop only in early XIX century.
The coats of arms of some peoples depict honeycombs and a bee - a symbol of hard work. Despite the thousand-year history of communication with bees and their use, man has not bred a single true breed of domestic honey bees. All three dozen breeds now existing are actually varieties of local wild forms. The most peaceful of all bees are Caucasian. In addition, they have an outstanding ability to collect nectar and are indispensable in countries with a mild climate. And the most aggressive are Cypriot bees. The largest bee is Italian, common in the countries of Southern Europe. In total, there are now approximately 40 million bee colonies in the world.
bee tongue
Honey bees use sound signals to communicate with relatives. During the wagging dance, they communicate the direction, distance, and richness of the food source. Other bees in the vicinity can hear the air vibrations created by the wings with the help of a sound-sensitive organ located on their antennae.
Of all the known insects, man has domesticated only the honey bee and the silkworm. When breeding bees, one could have honey and wax, and when breeding silkworms, one could have silk.
bee family
Honey bees live in large families: wild - in the hollows of trees, domestic - in hives. Each colony has a female - queen, several hundred males - drones (they live from the time they emerge from pupae until autumn) and up to 70 thousand worker bees. The queen bee is the largest bee in the family. Since spring, she lays eggs (up to 2000 per day). Drones - bees medium size with large eyes touching at the back of the head. They fertilize the uterus. All the work in the hive is done by the worker bees. They are smaller than the rest of the family.
honey bees
Families of honey bees can be attributed to pronounced social colonies. In the family, each bee performs its function. The functions of a bee are conditionally determined by its biological age. However, as established, in the absence of bees of older ages, their functions can be performed by bees of younger ages.
A distinction must be made between actual and biological age bees, since during the harvest the worker bee lives from 30 to 35 days, and during wintering the bee remains biologically young up to 9 months (Central Russian gray bee in the conditions of the north of Russia and Siberia). When specifying the terms of life and periods of development, bees are usually guided by the lifespan of a bee during the nectar flow.
Features of the structure and behavior of worker bees. On the underside of the abdomen of the worker bee there are smooth areas - mirrors. Wax is released on their surface. Bees make six-sided cells from it - honeycombs: large, medium and small. On the hind legs of the bees there is one "basket" and one "brush". With their help, they collect pollen. Arriving at the hive, the bees place it in the cells of the honeycombs. Other worker bees compact the pollen and soak it in honey. Perga is formed - a supply of protein feed. The nectar collected from the flowers is regurgitated by bees into cells from the honey goiter. Here it turns into honey - a supply of sugary food. In the special glands of worker bees, "milk" is produced. They feed them to the queen and larvae. At the end of the abdomen of worker bees there is a retractable serrated sting associated with a poisonous gland and used in defense.
Worker bees also perform other work: they ventilate the hive, clean it, cover up cracks, etc. Each of them goes through all kinds of activities during her life as she develops certain glands. Young worker bees (up to 10 days old) make up the retinue of the uterus, and the larvae also feed it, since royal jelly is well secreted in young bees. From about 7 days of age, wax glands begin to work on the lower part of the abdomen of the bee and wax begins to be released in the form of small plates. Such bees gradually switch to construction work in the nest. As a rule, in the spring there is a massive build-up of white honeycombs - this is due to the fact that by this period the overwintered bees have massively reached the biological age corresponding to the build-up bees.
By about 14-15 days, the productivity of the wax glands drops sharply and the bees switch to the following types of nest care activities - they clean the cells, clean up and take out the garbage. From the age of about 20 days, the bees switch to ventilation of the nest and protection of the notch. Bees older than 22-25 days are mainly engaged in honey collection. To inform other bees about the location of the nectar, the foraging bee uses visual biocommunication. Bees over 30 days old switch from honey collection to collecting water for the needs of the family. Such a life cycle of a bee is designed for the most rational utilization nutrients and use of the available number of bees in the colony. The largest number The body of the bee contains excess nutrients precisely when it leaves the cell. At the same time, most bees die when water is taken from natural reservoirs. Much less of them die when collecting honey from flowers and when approaching the hive.
bee development. The uterus lays fertilized eggs in large and small cells, and unfertilized eggs in medium cells. The larvae hatched from the eggs are fed by the worker bees with "milk". Then only the larvae of large cells receive "milk", the rest - pollen and honey. After the last larval molt, the worker bees seal the cells with wax. Soon the larvae pupate, and then adult insects emerge from the pupae. They gnaw through the wax caps and crawl out onto the surface of the combs. Queens come out of large cells, drones come out of medium ones, and worker bees come out of small ones.
Silkworm
The silkworm is a medium-sized white butterfly. Its caterpillars weave silk cocoons before pupation. Silkworm breeding began in China about 5 thousand years ago. In the process of domestication from generation to generation, butterflies were left for breeding, which laid many eggs and had underdeveloped wings, and their caterpillars wove large cocoons (their thread became up to 1000 m or more long).
The silkworm belongs to the class of insects, a representative of the arthropod type. This silkworm may be an example of a domesticated insect. As a domestic insect, people have been breeding the silkworm for several millennia, it has lost the properties of its wild ancestors and can no longer live in natural conditions. He developed a number of adaptations that greatly facilitate his breeding. So, for example, silkworm butterflies, in essence, have lost the ability to fly. Females are especially inactive. Caterpillars are also inactive and do not creep.
The silkworm, like other butterflies, develops with complete transformation. The silkworm butterfly has a wingspan of 40 to 60 mm. The coloration of her body and wings is off-white with more or less distinct brownish bands. By appearance The female silkworm is quite easy to distinguish from the male. She has a more massive abdomen than the male, and the antennae are less developed. On the first day after leaving the cocoon (silk shell), the female insect lays eggs, the so-called grena. A clutch contains an average of 500 to 700 eggs. Egg laying lasts three days.
A caterpillar emerges from the egg. She grows fast and sheds four times. Caterpillars develop within 26 - 32 days. The duration of their development depends on the breed, temperature, air humidity, the quantity and quality of food, etc. The silkworm caterpillar feeds on mulberry leaves. At the end of development, the caterpillar strongly develops a pair of silk-secreting glands. They intensively secrete a liquid, which quickly thickens in air, turning into a silk thread. From this thinnest thread, reaching 1000 m in length, the caterpillar twists a cocoon. In the cocoon, the caterpillar turns into a chrysalis. The shell of the cocoon protects the pupa from various adverse conditions.
Cocoons come in various colors: pink, greenish, yellow, etc. But for the needs of industry, only breeds with white cocoons are currently bred. A butterfly is formed from a pupa. It secretes a special liquid that dissolves the sticky substance of the cocoon. With its head and legs, the butterfly pushes the silk fibers apart and exits the cocoon through the hole formed. Over the past decades, various breeds of silkworms have been bred, differing in the size of cocoons, their color, length and strength of the thread.
Tasks:
- introduce students to the diversity of hymenoptera; reveal their characteristic features, role in nature and human life; to acquaint with the peculiarity of the life of social insects; bring to the formation of the concept of "instinct";
- to continue the formation of skills to compare groups of animals with each other, to find features of complication, to work with additional literature; to continue the formation of a careful attitude of students to nature.
Equipment: computer equipment, presentation on this topic of the lesson (Appendix 1), honey in combs, propolis, royal jelly, additional literature on this topic.
During the classes
I. Organizational moment.
II. Knowledge check.
Front poll:
BUT) General Features insects
b) What insects belong to the order Lepidoptera?
C) List the main features of the representatives of this detachment.
D) What insects belong to the order Homoptera?
D) What insects belong to the order Diptera?
E) What danger do flies and fleas pose to humans?
Individual survey:
Cards:
No. 1. Answer the test questions:
For each test question, find only one correct answer:
1. The silkworm, which was domesticated by a person in order to obtain silk, belongs to the order:
A) Lepidoptera
B) homoptera
B) Diptera
2. Sucking mouthparts have insects belonging to the order
A) Lepidoptera
B) homoptera
B) Diptera
3. They have one pair of wings, and the second modified into halteres insects belonging to the detachment:
A) Lepidoptera
B) homoptera
B) Diptera
4. Common aphid belongs to the order
A) Lepidoptera
B) homoptera
B) Diptera
5. Caterpillars of which butterfly damage clothes, shoes, carpets:
A) cabbage whites
B) silkworm
D) lemongrass.
1. From the listed signs, select separately those that characterize the representatives of the homoptera and characterize the Diptera:
A) sucking insects that feed on plant sap;
B) mouth apparatus licking or piercing-sucking;
C) two front wings are well developed, the hind wings are either very small or absent; there are wingless individuals;
D) two pairs of transparent wings, the anterior wings are better developed; sometimes there are no hindwings;
E) development proceeds with complete transformation;
E) development proceeds with incomplete transformation.
Homoptera are characterized by: __________________________________
Diptera are characterized by: ____________________________________
№3. Write down examples of Diptera that are:
blood-sucking __________________
forming galls ________________
predatory ________________________
pests of plants _____________________
orderlies-destroyers _________________
III. Learning new material.
Today, biologists-entomologists __________ who study bees and ants, an ecologist _________, and a doctor _________ help me in the lesson.
Teacher's explanation using computer presentations .
1. general characteristics insects of the order Hymenoptera (slides 2-9)
A) the number of species, representatives
B) distribution
C) structural features of the wings
D) the presence of antennae and eyes on the head
D) type oral apparatus
E) type of development
G) meaning in nature and human life.
2. The external structure of the honey bee (slide 10).
3. The composition of the bee family (slide 11).
bee seven I consists in the summer of 40-80 thousand adult bees - the offspring of one uterus- the only oviparous female in the entire hive. For a year it can lay up to 150 thousand eggs, in the spring up to 3 thousand eggs per day. She does nothing else, she is fed by worker bees.
The bulk - worker bees, also females, but with reduced genitals. The first three days after birth, they act as cleaners. Then they start feeding adult larvae with bee pollen - this is a mixture of pollen and honey. On the seventh day, they have special glands in which bee milk is produced and they begin to feed the queen and young larvae. On the tenth day, these glands disappear, and wax glands form - the bee switches to building honeycombs and processing nectar into honey. With the advent of poisonous glands, it plays the role of a watchman.
And only on the 21st day, the worker bees fly out to collect nectar. Why?
In spring and summer, there are also male drones in the family. They are unable to forage on their own (short tongue). After mating with the queen, the need for them disappears, they are driven out of the hive or not allowed back, the drones quickly die of hunger.
There can only be one queen per hive. When a new one appears, the old one, together with part of the worker bees, flies out of the hive, they hang in a mass somewhere on a tree branch - this is swarming. If the beekeeper does not place such a swarm in a new hive, they fly away somewhere and establish a new dwelling on their own.
IV. Press conference. Questions are asked by students of the class, “biologists-entomologists”, “doctor”, “ecologist” are answered by students of the class.
Question: How do bees manage to build such geometrically correct structures - honeycombs?
How do bees manage to build such geometrically correct structures - honeycombs?
Slide 12. Where construction work is going on, dense clusters of builders hang, the temperature of 35 degrees is maintained inside each cluster. This temperature is necessary for the "sweating" of the wax. Its small scales protrude from the bee's four wax glands located on the underside of the abdomen. With its hind legs, on the legs of which there are special bristles, the bee picks up wax flakes and passes them to the mouth with its front legs. The builder thoroughly chews each wax flake, mixing the wax with saliva. Due to the high temperature, the wax acquires an ideal degree of softness.
It is surprising that the honeycomb is not built cell by cell: there are many hexagons at work simultaneously at different points. In addition, the builders often change, sometimes every half a minute. Before sticking its wax ball, the bee learns where the work stopped and continues it correctly. When erecting a wall, the bee first lays a roughly molded wax roller, then pulls it into a thin sheet with planing and pulling movements of the jaws.
The wall thickness is repeatedly checked, excess wax is removed. The final wall thickness is 0.073 mm. Deviations in one direction or another is not more than 0.002 mm. How can bees determine wall thickness? It turns out that the ends of the palps continuously touch the wall. The "measuring instruments" are the front legs, as well as a group of highly sensitive hairs on the back of the bee's head.
Despite the fact that honeycombs are built from different places at the same time, it is impossible to see the joints on the finished honeycombs.
Question: What is the bee dance?
Slide 13. Worker bees dance on the comb to tell others where to find nectar-rich flowers. The angle between the axis of the body and the vertical axis corresponds to the angle between the direction of the food source and the sun. If the food source is within 100m, the bee dances in a circle; if it is further, the bee draws a figure eight.
Question: How do bees survive winter?
For the winter, the bees huddle in a tight ball, in the middle, where the queen is kept, the temperature is about 25 degrees due to the increased muscular activity of the worker bees. At this time, the bees cover the energy needs at the expense of the stocks of honey or sugar syrup, which the beekeeper provides them.
Question: What are the medicinal qualities of honey?
Bee honey is a unique food, dietary and medicinal product produced by honey bees from the nectar of flowering plants. It has a high calorie content (100g-320 kcal). Mankind appreciated bee honey in ancient times. They have always cured colds.
Mathematician Ancient Greece Pythagoras claimed that he lived to a ripe old age thanks to the systematic use of honey.
An outstanding physician, naturalist and poet Ibn-Sina pointed out: “If you want to keep your youth, then be sure to eat honey.” He especially recommended the regular use of honey to people over 45 years of age.
Honey has a calming effect on nervous system and can be used as a sleeping pill. It reduces a sharp irritating cough, cures sore throats, liver and kidney diseases, any colds, relieves arthritis pain.
Bee honey stops the growth of bacterial flora. Pathogenic bacteria of Escherichia coli, dysentery die in it. When a person consumes comb honey, the wax that enters the stomach is not absorbed by the body. It turns into a soft elastic lubricant and has a beneficial soothing effect on the stomach and intestines.
Question: What is propolis? What can be used for?
Propolis or “bee glue” is a product of processing by bees of the resinous substances of pollen grains collected on the flowers of medicinal plants.
It is used by bees to seal holes and crevices in the hive. Another use of propolis concerns those cases when an animal is taken into the hive. Armed with stingers, the inhabitants stab the intruder, and then cover it with an air-tight shell of propolis - the corpse is mummified. By preventing rotting in this way, bees protect themselves from possible infection.
Propolis was used to make that mysterious lacquer with which the old Italian masters covered their violins in order to achieve the best sound.
Propolis has pronounced antimicrobial properties, vitamin P activity, analgesic effect. An alcoholic solution of propolis can cure, for example, inflammation of the middle ear.
Teacher's explanation. Ant family (slide 14).
There are approximately 10,000 species of ants in total. The community is more complex than that of bees. In an anthill there can be up to 1 million individuals, at the same time up to ten females.
An anthill is a complex structure, including underground and above-ground parts.
Constantly shoveled, a certain temperature is maintained. How?
Continuation of the press conference.
Question: How are responsibilities distributed in the anthill?
Most of all in the anthill there are working ants - wingless females that perform all the work except laying eggs - they take care of the larvae, shovel the anthill, protect it, and bring prey to the anthill. In wood ants, workers can vary in size. Young males and full-fledged females are easily recognized by the presence of wings. After mating, the females shed their wings, lay eggs, and establish a new anthill. Males die after mating.
Question: What do ants eat?
Slide 15. Most ants prefer a mixed diet, and their favorite treat is sweet vegetable juices. However, ants rarely manage to get sugary liquid on their own, usually they resort to the mediation of aphids. By tickling their belly with their antennae, the ants cause the aphids to secrete a drop of sugary excrement. This is why aphids are called the “cash cows” of ants.
South American leaf cutter ants bring pieces of leaves to the nest, grind them, prepare a nutrient medium for growing mushrooms, close relatives of our cap mushrooms. The club-shaped thickenings that form on the mycelium are eaten by the ants themselves and fed to their larvae.
Reaper ants living in Europe bring cereal seeds to their nests. The worker ants spend hours chewing on the grains, turning the starch into sugar. This is how “ant bread” is obtained, which adult ants and their larvae feed on immediately or after long-term storage.
Some ants are able to store honey for future use. The role of vessels is played by large worker ants. In times of famine, ants - honey barrels drop by drop give the contents of their goiter to other inhabitants of the nest. One such “barrel” can feed a hundred ants for two weeks.
Question: what insects of the order Hymenoptera are listed in the Red Book?
Answers “environmentalist”, using his own drawings of rare insects
Teacher's explanation. Is the complex activity of social insects congenital or acquired? What is instinct?
An instinct is a sequential chain of innate responses to various stimuli.
V. Consolidation of knowledge.
Checking the record of the general characteristics of insects of the Hymenoptera class by students in notebooks.
Crossword work.
VI. Homework: prepare for a generalizing lesson and defense of projects.
VII. Summing up the lesson. Grading.
Social and domesticated insects
Most insects lead a solitary lifestyle. However, there is alsosocial insects . These includetermites, bumblebees, wasps, bees, ants . The community of these insects is one big extended family. Social insects share food with each other, take care of the larvae together, and guard the nest.
Bees and ants are social insects
bees.The social insects arehoney bee . A large family of bees has up to 100 thousand individuals that live in a hive. Most of the insects in the hiveworkers bees. These are infertile females in which a modified ovipositor serves assting . They clean the hive, collect nectar, take care of the queen and larvae, protect the hive from enemies. They live one warm season (less than a year). In a bee family, the main bee isuterus , which lays eggs - up to 2000 per day. The queen is larger than the worker bees. She lives for about five years. In the spring, in May - June, a new queen and several dozen males appear from the pupae in the bee colony, which are calleddrones: they do not take any part in the work, and their main task is the fertilization of the uterus. In autumn, the worker bees drive the remaining drones out of the hive and they die.
All care about the hive lies with the worker bees: growing up, each worker bee changes several "professions". She builds combs, cleans cells, feeds larvae, takes food from incoming bees and distributes it in the hive, ventilates the hive, guards it, and finally begins to fly out of the hive for nectar. Bees communicate with each other in the same way as ants - with the help of touch and excreted substances.
However, only bees have a "language of dance". With the help of special body movements and movements, one bee can tell others where the nectar-rich flowering plants . The scout bee "dances" in the hive on the combs.
On the underside of the abdomen of the worker bee are special glands that secretewax . From it, bees, thanks to complex instincts, buildhoneycombs . On the hind legs of bees there are areas surrounded by long chitinous hairs - baskets. The bees crawl over the flowers, and the pollen falls on the hairs of the insect's body. Then the bee cleans the pollen into the basket with the help of special brushes on the paws of the legs. Soon a ball of pollen is formed there - a pollen, which the bee transfers to the hive.Perga - Pollen impregnated with honey - serves as a reserve of protein food for the bee colony.
Worker bees have a peculiar expansion of the esophagus -honey goiter . From the nectar collected from the flowers, which passed through the honey goiter, the main food supply of the bee family is formed -honey . Cells are filled with honey, which the bees cover with a thin wax layer. For a year, up to 100 kg of honey can be obtained from one bee family.
Although man has been breeding bees for a long time, collapsible frame hives were invented relatively recently - in 1814 by the Ukrainian beekeeper P. I. Prokopovich. Prior to this, in order to extract honey from a bee nest, which, as a rule, was located in a hollowed-out log of a tree, it was necessary to break the honeycomb, that is, to ruin the bee colony. The surviving swarm of bees can live independently, without human help. This indicates that bees are not yet fully domesticated.
Ants- social hymenoptera. They do not have a sting, but a poisonous gland has been preserved, thanks to which they can protect themselves from enemies. redheads forest ants are of great benefit to the forest. Ants of one anthill eat tens of thousands of insects per day and protect the forest on an area of 0.2 hectares from pests. They live in families.
The anthill consists of above-ground and underground parts. Most ants living in an anthill are wingless working individuals - these are barren females. Their number sometimes reaches a million. In addition to them, a queen lives in an anthill. She doesn't have wings either. She breaks them off after the nuptial flight. All her life she lays eggs, and all the care of the anthill lies with the worker ants. They forage, repair and clean the anthill, feed the larvae and the queen, defend the anthill in case of attack by enemies. Once a year, at the beginning of summer, winged females and males appear from pupae in the anthill, which go on a mating flight. After mating, the males die, and the females shed their wings and found a new anthill. They can also get into the anthill in which their development took place.
Most ants are predators. Some feed on the sweet secretions of aphids. For this, ants guard, "graze"these insects that feed on plants, and sometimes build shelters for them. Other types of ants breed mushrooms in underground chambers for their food, bringing crushed plant leaves for this. There are herbivorous ants.
Ants communicate by touching each other with their antennae, legs, and head. In addition, they have a "chemical language" - they secrete special substances with which they mark their paths. By smell, ants recognize relatives and enemies.
With the false behavior of social insects is called instinctive because instinct - a set of innate moments of behavior, fixed hereditarily and characteristic of a certain type of animal. The behavior of bees, ants, and some other animals is so amazing and complex that it leads many people to believe that it is intelligent. However, these actions of animals are instinctive, unconscious.
domesticated insects
There is only one completelydomesticated insect , not found in nature in the wild, -silkworm ; females of this species even "forgot how" to fly. An adult insect is a thick butterfly with whitish wings with a span of up to 6 cm. The caterpillars of this silkworm eat only mulberry leaves, or mulberries.
Scientists suggest that in the wild, the ancestor of the silkworm lived in the foothills of the Himalayas. The butterfly was domesticated in China around 3,000 BC. e. Nowadays, this insect is completely domesticated. It is bred in China, Japan, the countries of Indochina, in Southern Europe, South America, Central Asia and the Caucasus - where the mulberry tree can grow. There are several dozen breeds of silkworms, differing in length, strength and color of the silk thread they produce.
Silkworm females lay eggs (each female - up to 600 eggs), which are calledgrenay . Caterpillars emerge from them. These caterpillars are fed with mulberry leaves in special rooms on the aft shelves. When pupating, each caterpillar viet for three days.