Variety of insects: how can the structure of a cockroach surprise?

The arthropod colony swarming in the substrate is a typical picture of modern tropical forests. Insect cockroaches are the oldest representatives of newwing with incomplete transformation. Over the years of evolution, they have not undergone major changes. Arthropods became real cosmopolitans, spreading to all continents except Antarctica. Cockroaches are hardy and agile, shy and omnivorous. Some species became synanthropic insects.

Classification

Order Cockroach (Blattopera) belongs to the class of insects, type of arthropods. To an extensive group of 7570 species, termites are included. Cockroaches are representatives of the cockroach superorder (Dictyoptera). It includes new-winged insects with incomplete transformation. 4640 species of cockroaches were found and studied in the world. Among scientists there is a constant debate on taxonomy. The authors divide the cockroaches into different numbers of families and subfamilies, classify them together and separately with termites.

According to the latest data, 8 families were identified: Nocticolidae, Corydiidae, Blaberidae, Ectobiidae, Cryptocercidae, Tryonicidae, lamproblattidae, Blattidae. The greatest diversity of species is noted in the tropics. Insects found plenty of food and shelter in warm and humid forests. 55 species of cockroaches live in the CIS. Some of them are synanthropic, living next to a person.

Information. Is a cockroach an insect or an animal? In everyday mention, animals are called tetrapods, but in the scientific classification they include many organisms. Insects are arthropod invertebrates.

Cockroach structure

Despite the species diversity of the detachment, the structure of the bodies of its representatives is very similar. The morphology of adults (adults) is typical. Differences appear in size and color.

The external structure of the cockroach

The body of insects is flattened, oval in shape. This structure allows you to crawl into narrow slots and holes. The length of imago ranges from 9 to 95 mm. The color of the cover is often dark - brown, black, brown. Reddish and coffee stains are less common. Nightlife, secrecy and the need for camouflage do not require the presence of bright colors.

Interesting fact. The largest species is the Madagascar hissing cockroach, its length up to 100 mm. For comparison, the size of the Prusaks is 9-10 mm. More popular information will tell “Interesting facts about cockroaches: what we know about these insects”.

Body parts of a cockroach

Insects consist of three main departments: head, chest, abdomen. The separation of the body contributes to its mobility. The functional significance of each department:

The head is triangular or heart-shaped, movable, covered from above by the shield of the pronotum. On it are the organs of vision and touch. Antennae are mobile appendages consisting of segments. Type bristle-shaped. Functions of the antennae of a cockroach: touch and smell. With the help of appendages, they determine the taste of food, find sexual partners, contact between individuals. The oral apparatus is pointing down.

Information. The number of segments in the antennae increases with the age of the larvae.They are added after molting.

Chest - The middle section consists of three segments, divided into tergites and sternites. The upper half-rings form the back, the lower - the chest. The largest segment of pronotum, it is flat and convex. Elytra and wings are attached to it. Each part of the chest has one pair of limbs.

Abdomen - the largest department consists of 10 segments. At its end there are paired articulated appendages of the church. In the abdomen are respiratory and digestive systems, in females ovipositors. On the 10th tergite is the anal plate.

Features of the structure of cockroaches

On each of the main parts of the body there are organs that ensure the vital activity of insects.

What are the eyes of a cockroach

The main organ of vision in cockroaches are complex or faceted eyes. They are located on the sides of the head. They have various sizes (large in winged forms) and kidney-shaped. The interocular space is well defined. Additional organs of vision simple eyes help evaluate the intensity of lighting. They are small, located in the upper part of the head. How many eyes does a cockroach have? Insects have 2 main eyes and 2 simple eyes, which atrophied in some species.

Learn about the phenomenal endurance of insects in the article “Without food, water and a head: how many cockroaches live?”.

Type of oral apparatus of cockroach

Solid food insects have developed a gnawing mouth apparatus. It consists of several parts:

• The upper lip - sensitive hairs on its surface help with the study of food.
• The upper jaw (mandibles) - consist of a strong chitin plate with teeth. Serves for biting and grinding products.
• The lower jaw (maxilla) - a moving organ consists of several segments, supports food during grinding.
• Lower lip - helps push food into the throat, its palp is the organ of touch.

The oral apparatus of the cockroach has remained unchanged for the entire period of its existence. It allows you to absorb plant residues and any organic matter.

Limbs cockroach

Running is the main way for the representatives of the cockroach squad to travel. The structure of the legs helps them in this. The limbs are composed of 5 parts. They are attached to the body with the help of a basin having well-developed muscles. The longest segments are the thigh and lower leg. The flexible foot consists of 5 segments. There are spikes on the legs and hips. How many legs does a cockroach have? Insects have 2 pairs of limbs, each of which is attached to a specific section of the chest.

Information. Some species have a suction cup on the foot, allowing insects to move along vertical surfaces.

Limbs are used not only for running and jumping. With them, adults cleanse the antennae and body of food debris. The legs are flexible and mobile, they allow you to quickly change the trajectory of movement in case of danger. The average speed of the Prusak is 3-4 km / h.

The structure of the wings of a cockroach

The progenitors of insects had developed wings and the ability to fly. Many modern species have lost it. Appendages appear only in the imago. They consist of two pairs. The first is leathery elytra. They perform a protective function and do not participate in flight. The second pair is webbed wings. The length and development of appendages depends on the species. Females have less developed wings. In a calm state, insects stack them on their backs.

Flying cockroaches most often live in the tropics, but some species are found in Central Asia and Europe. Of domestic insects, the ability to fly is demonstrated by an American cockroach. Although the Prussians have long wings, they rarely spread them, they can plan them.

The internal structure of the cockroach

The vital systems of insects are provided by the main systems:

• circulatory;
• Nervous
• digestive
• excretory.

To understand how insects can live for months without food and about a week without a head, you need to study them in more detail.

Circulatory system - blood (hemolymph) flows in the space between the internal organs of the insect. There is only one vessel in the body connected with the heart. The main muscle. The pumping blood consists of 13 chambers, 2 of them are in the chest, the rest in the abdomen. The function of the blood is to transfer nutrients and excrete decay products. The respiratory system is involved in the distribution of oxygen. This is the main cause of vascular reduction. Blood movement is slow, the insect does not maintain a constant body temperature.

Information. If the head is deprived of a cockroach, the hemolymph quickly agglomerates, the body does not bleed.

The respiratory system in a schematic image resembles a tree. It consists of a tracheal system that entangles all important organs. Branches departing from the main trachea, gradually decreasing in diameter. The system is connected to the environment with the help of 10 stigmas, which are called spiracles in cockroaches. Two pairs of stigmas are located on the sides of the chest, the main part is placed on the abdomen. Breathing is carried out with the reduction of the department.

The digestive system is the intestine, divided into several sections. In the mouth, food is rubbed and moistened with saliva. Then it is pushed into the throat, then into the goiter, where digestion and absorption begin. Small portions of food are served in the stomach. It is prepared and sent to the middle intestine. In this section, the digestive secretion is secreted and the main absorption occurs. Excrement exits through the anus.

The excretory system or malpighian vessels remove decay products from the body through the hind gut.

What is covered with the body of a cockroach

A typical arthropod cover is the chitinous membrane. For cockroaches, this is a carapace that protects internal organs. It allows the body to maintain its shape, serves as a skeleton. The outer cover prevents the rapid evaporation of moisture. At the base of the extremities, the chitin layer is thinner to provide leg mobility. The hard shell limits the growth of insects. During development, the larvae have to dump it. The carapace is cracked tight, the insect gets out of it. At first, his body was white and soft. This is a sign of a lack of chitin. After a few hours, the cover is restored.

Information. A meeting with shed arthropods gave rise to myths about white cockroaches.

Propagation Features

Cockroaches have males and females. They attract potential partners with the help of chemical odors - pheromones. Males of some species perform mating dances during courtship. A fertilized female lays eggs in a special capsule formed in the abdomen. In a special chamber, sticky secrets envelop each egg and form a shell. Females carry it in the abdomen, periodically push it out for ventilation. For the development of embryos, a high temperature of about 30 ° is required. Detailed description of the asset in the article “How many cockroaches hatch from one egg?”.

The duration of wearing depends on the type, some discard the swelling after 7-14 days, others are kept in the abdomen until the larvae are born. Egg cocoon helps increase offspring survival. This is the first food of the larvae. Young growth is born white, with a soft cover. Larvae stay near the mother or burrow into the ground. Before becoming adults, they pass 3-12 ages. Each is accompanied by molting - dropping close carapace.

Offspring are called larvae or nymphs. Outwardly, they resemble adults. The differences are:

• small size;
• lack of genitals;
• a small number of segments of antennae;
• devoid of wings.

Larvae make up the bulk of the colony. They show greater caution than adults, more often burrow into the ground. Development takes from several months to 1-2 years. With decreasing temperature, the larvae grow poorly.

Food

Under natural conditions, most cockroaches are vegetarians, they eat fallen leaves, fruits, dead plants.Some species are omnivorous; their diet is expanded to include the remains and excrement of animals. Domestic insects feed on any products found in the apartment. Sweets, bread and pastries, as well as fruits, are preferred. Learn about the diet of domestic pests in the material "What do cockroaches eat: what diet to make at home?".

Harmful insects

Synanthropic species living in human dwellings are a potential threat to health. In search of food, they examine the sewer, garbage chute, rodent burrows. Pathogenic bacteria, fungi, helminth eggs remain on the paws of insects. Dangerous microorganisms are transferred to food, bedding, furniture. With irregular hand washing, there is a high probability of contracting dysentery, tuberculosis, diphtheria, and hepatitis.

Particles of chitinous cover scattered by larvae after molting cause severe allergic reactions. People develop chronic rhinitis, asthma. All information about the threat to human health in the article "What are cockroaches dangerous: can a small insect bring big problems?".

In addition, pests spoil food, books, wallpapers. They prefer secluded warm places, so they crawl into electrical appliances. Insects cause a short circuit and breakdown of equipment. Any means are used in the fight against synanthropes: freezing rooms, glue traps, poisoned baits, insecticides. Processing apartments with special chemicals is an effective way to get rid of insects.

Only a few synanthropic species of cockroaches received the status of pests of stocks and carriers of infectious diseases. The bulk of insects plays a significant role in the global ecosystem. Arthropods are exterminators of plant and animal remains, food for animals, birds and reptiles.