Insects are arthropods. Their characteristic feature is the presence of limbs, consisting of separate segments. The class Insects is the most numerous and contains about 1 million species. Cockroaches, grasshoppers, beetles, butterflies, wasps, bees - it is simply impossible to list them all! What features allowed them to become so widespread? The topic "Insects and their features" is very interesting. Let's explore it in more detail.
Building
The parts of the body that insects have (see photo in the article) are the head, chest and abdomen. There is a pair of antennae on the head, the length of which varies and serves as an important systematic feature.
Insects are arthropods with a wide variety of types of mouthparts. The following varieties are distinguished: gnawing - in cockroaches and beetles, piercing-sucking - in aphids and mosquitoes, licking - in flies. The type of mouth apparatus depends on the nature of the food. In bees and bumblebees, it is chewing and licking, and in butterflies it is sucking.
The chest of insects consists of three segments, each of which bears a pair of jointed limbs. Most representatives of this class also have wings here. They areare outgrowths of epithelial tissue. Fleas and lice do not have wings due to their lack of functional need. The abdomen is almost always devoid of limbs.
The cover of insects consists of chitin carbohydrate, additionally coated with a wax-like substance. It protects the body from excessive water evaporation. The integument also has special hairs that act as organs of touch and hearing.
Wonderful transformation
Insects develop in a special way. In organisms with incomplete transformation, an imago is formed from a larva - an adult. Moreover, these two stages do not differ in morphological features except for size. This is how the development of such orders as cockroaches, orthopterans, termites, lice, bedbugs and praying mantises occurs.
Coleoptera and fleas have a different type of transformation - complete. Its essence lies in the fact that the larva at an early stage of development leaves the egg, turning into a chrysalis. At this stage, the destruction of the original organs and the formation of new ones. This is how an adult is formed. An important fact is that the larva and imago are not similar in appearance. For example, the Colorado potato beetle at the initial stage of development looks like a small worm.
Habitat
Insects are one of the few representatives of the animal world that have mastered all habitats. So, termites are able to make moves in the soil at a depth of 35 m, many bugs are adapted to life in water. Members of the order Hemiptera are parasites. But the predominant part is distributed in the ground-air environment.
Characteristic signs of insects
Insects (photos show a variety of representatives) have signs by which taxonomists distinguish them into a separate class of the Arthropod type. These are three pairs of limbs and body parts (head, chest, abdomen), the presence of a pair of antennae on the head, the respiratory organs are tracheas, and the discharge is Malpighian vessels.
Diversity and importance of insects
Which insect from the order Hymenoptera is social? Of course it's a bee. Its main significance lies in obtaining honey and bee bread from pollen.
Representatives of the order cockroaches fly very poorly, but they orient themselves well in space with the help of long antennae.
Locusts, mole crickets and crickets are orthopterans. This order includes both grasshoppers and crickets, which have special adaptations. This is the so-called mirror - a thin membrane - and a bow - a vein with teeth.
Insects belonging to the order Bedbugs have a flattened body on which wings are not formed. Their absence is compensated by the ability to easily jump a decent distance.
Insects - these are all representatives of the beetle order, having hard elytra that tightly cover the abdomen.
Who among us has not admired the fluttering flight of beautiful butterflies? They are also insects. They are not only beautiful. Many of them are useful. So, the silkworm "leads" the whole production. It is artificially bred in manycountries of the world. And the product of her life is natural silk.
Thus, insects are a class of arthropods, most of which are adapted for flight. Thanks to a fairly high level of organization, they have mastered all habitats, occupying their niche in the system of the organic world.
