The second and third segments on the dorsal part usually carry a pair of wings.
The problem of wildlife protection is due to the reduction of stocks of valuable species of fish, fur animals, wild animals that do not harm humans. In this regard, the relevant authorities are responsible for controlling and regulating the rules of hunting and fishing. Relevant decisions of legislative bodies have been adopted.
The growing scale of mineral extraction raises the problem of subsoil protection. It is necessary to provide rational use of subsoil and reduction of losses of useful components at extraction and processing. To do this, it is necessary to introduce the integrated use of mineral raw materials, widely use modern efficient technologies for extraction and processing of poor ores, waste disposal.
Insects with incomplete transformation: general characteristics. Abstract
Insects are true terrestrial invertebrates. The class has about 1 million species. The body of insects is clearly divided into the head, chest and abdomen. The head is synthesis statement example formed by four segments. The thoracic department consists of three segments, each of which has a pair of limbs. The second and third segments on the dorsal part usually carry a pair of wings. The abdomen consists of 6-12 joints
Development with incomplete transformation is characterized by the fact that from the egg shells comes an insect, similar in appearance, lifestyle and nutrition to the adult form, but smaller in size. As a result of intensive feeding, it grows, but the chitinous cover prevents an increase in linear size and volume. This leads to molting, during which the tight chitinous cover is removed. Beneath it is a new soft cuticle in the form of folds. After removing the old cover, the new cuticle straightens. The size of the animals is increasing.
After several moults without the formation of a pupa, the animal reaches maturity, its wings are formed, the gonads mature, and the external genitalia appear. This is how orthoptera, lice, bedbugs, etc. develop.
Insects whose development takes place with incomplete transformation are representatives of several series, including the series of Rectopus (migratory locusts, mares, grasshoppers, crickets, etc.).
Rectopils have oral organs of the rodent type, their upper wings are long, narrow and thickened, and the wings themselves are wide and soft. The hind limbs are very well developed and much longer than the front and middle; due to this, orthoptera jump long distances.
Locusts reach 5-6 cm in length. It is very voracious, feeds on plants of all kinds. It constantly lives and breeds in reed thickets in the lower reaches of the Terek, Kuban, Ural, Amu Darya, and Syr Darya rivers. In late summer, the locust lays its eggs in the soil. They are glued together and form a so-called cup.
In the spring, the eggs hatch into larvae, similar in structure to adult insects, but some organs, including the wings, are still underdeveloped. Such larvae are called foot locusts. The larvae grow, molt and turn into adult winged insects. Migratory locusts from their habitats can fly long distances and cause significant damage to crops. The main method of controlling locusts is the use of various poisons.
Some of the most prominent insects are the Cockroaches. These are nocturnal animals. Cockroaches feed mainly on plant and animal remains; oral apparatus of the rodent type. In Ukraine, only a few species of cockroaches live in natural conditions, and in human dwellings – black cockroach and cockroach, or red cockroach. In the Crimea, these cockroaches are found in nature.
A number of lice are wingless external parasites of mammals. Due to this, their body is flattened, there are no wings, and the legs are adapted to hold on to the hair. In humans, three types of lice parasitize (pubic, head and clothing). They are especially dangerous because they carry pathogens of deadly diseases (typhus and relapsing fever). No one is safe from infection with this parasite, but if you follow the rules of personal hygiene, they are easy to get rid of.
Representatives of a number of bedbugs, or semi-hard-winged, have a prickly-sucking oral apparatus in the form of a proboscis. Their front wings are transformed into half-wings. At the base they are leathery, and near the top – membranous. This series includes a well-known pest – a bedbug – a harmful turtle that sucks the grains of cereals. In human homes live a bedbug-flea, which feeds on its blood. One of the most famous water bugs is water meters.
A number of Isopods include insects with a prickly-sucking oral apparatus and two pairs of membranous wings of the same structure, the hind of which is smaller in size. They feed on isopods of plant sap. Cicadas are one of the loudest singers among insects. They live in the Crimea and tropical countries. A large number of species of sedentary aphids cause damage to cultivated plants.
A number of dragonflies unite predatory insects, the larvae of which develop in the water, hunting for appropriate prey, even the fry of fish and tadpoles. The larvae breathe through the tracheal gills. Adults attack prey in flight. They have a very mobile head with large eyes and a gnawing mouthparts, an elongated slender body with two pairs of reticulate wings. These are the most skilled flies among insects. They are able to hang in the air and develop a high (up to 100 km / h) speed. Distributed in Ukraine (grandmother-rocker, grandmother-watchman),
Insects with complete transformation include the following series:
Lepidoptera, Diptera, Hymenoptera, Solid Wings and others.
Representatives of a number of Lepidoptera (butterflies) have two pairs of wings. They got their name because their wings are covered with modified hairs – scales, which are often brightly colored and form characteristic “patterns” on the surface of the wings.
On the head of butterflies are faceted eyes and a pair of antennae that have olfactory organs.
The segments of the thoracic department are interconnected. The pectoral legs are weak, sometimes thin and weak, but very tenacious. With the help of legs, butterflies are kept on flowers, plant stems, tree bark, etc.
Oral organs in adult butterflies of the sucking type. They are transformed into a proboscis, which is adapted to suck nectar from flowers. Larvae (called caterpillars) have a rodent-type oral apparatus. They feed on leaves, fruits and other parts of plants.
Butterfly caterpillars have spinning silk-secretory glands that secrete substances that solidify in the air, forming strong threads. Different types of caterpillars use THESE threads in different ways: they descend from tree branches; weave shoots and leaves or build special covers in which pupae (moths) are formed; form cocoons (real silkworms), etc.
Butterflies attach eggs to the branches of plants, the bark of trees, that is, where their caterpillars feed. Butterflies are helped to find such plants by olfactory organs. With the help of faceted eyes butterflies not only distinguish colors, but also determine the shape of objects.
Many butterflies (white cabbage, winter moth, oak silkworm, meadow butterfly, etc.) cause significant damage to agriculture and forestry. For example, white cabbage caterpillars cause great damage to cabbage. It was found that, due to the good visibility of caterpillars on cabbage leaves due to the variegated color and the ability to stay in groups, they are not destroyed by birds, as they are inedible, which is consistent with their bright color. The green color of the caterpillar in many other species of butterflies is protective.
Cabbage white goose has a greenish color. On the sides of the body and on the back she has yellow stripes and black spots. As it grows, the caterpillar crawls on a tree, wall, fence, etc., where it turns into a pupa. After leaving the pupa, the butterfly sits in one place for several hours, until its wings straighten and strengthen.
To control white cabbage, weeds should be destroyed, caterpillars and eggs collected and destroyed, and biological control methods used.
However, if the larval forms of butterflies cause significant damage, the adult forms are of great benefit by pollinating many species of plants. In addition, it is the main food for birds. This should be taken into account when developing plant protection methods.
Among the many species of silkworms, which got their name due to the fact that their caterpillar turns into a pupa in silky cocoons, of great importance is the silkworm – the only fully domesticated species of butterflies, food for silkworm caterpillars are mulberry leaves and mulberry leaves. associated name of the insect.
Under natural conditions, the silkworm does not exist. It was first domesticated by the Chinese at least 2.5 thousand years ago. In the VIII century. the Arabs brought him to Europe. Today, silkworm breeding is widespread in many countries around the world. Man has bred different breeds of silkworm, which differ in the amount of silk in the cocoon (from 1 kg of raw cocoons get up to 90 g of raw silk).
Although butterflies have wings, silkworms have lost the ability to fly as a result of domestication. The silkworm does not feed in adulthood. Males have a thin abdomen and pinnate antennae. Fertilized females lay eggs or grains, after which they soon die. From them in special rooms deduce a caterpillar which has whitish color and the worm-shaped form. At the end of the abdomen they have a horny appendage. The caterpillar is sedentary, develops 26-40 days; during this time it sheds four times. An adult caterpillar weaves a cocoon from silk thread produced by its silk-secretory glands. The cocoons are frozen with hot steam, dried, unwound and get natural silk.
Biplanes. This series includes mosquitoes, flies, mosquitoes and more. They have only the front pair of wings, the second pair is significantly reduced and only mace-like formations – buzzers – have survived from it.
The housefly is widespread everywhere. On her head are faceted eyes and tendrils – olfactory organs, on the paws – taste organs. Between the claws of her paws is an adhesive, hair-covered pad that allows the mousse to crawl on vertical planes, glass, ceiling. The limbs also have hairs that are easily adhered to by dirt, so flies are mechanical vectors of pathogenic bacteria. Up to 6 million bacteria were found on the body of one fly, and up to 28 million in the intestines. About 40 different types of microorganisms were found in the flies.
The main role in the formation of flies of the oral apparatus of the licking type belongs to the lower lip, which has the shape of a proboscis.