In our article we will consider the structure of cockroaches. Traditionally very unpleasant associations are associated with these insects. But in fact, these animals have a number of unique features. We’ll talk about this.
Classification
The structural features of cockroaches determine their systematic position. These animals are representatives of the type Arthropods, subtype Tracheal-breathing, class Insects, order Cockroach.
Like other representatives of this systematic unit, their characteristic features are the presence of three parts of the body - the head, trunk and abdomen, the fatty body in the cavity, the striated muscles and the external skeleton in the form of a cuticle.
Etymology
The name of this insect is found in several languages. At the moment, scientists have not been able to establish the exact origin of the word. Translated from Chuvash, it translates as "runaway." And this is no coincidence. Cockroaches are champions in speed of movement among all terrestrial insects.
And it’s very difficult to catch him. The fact is that in a second cockroaches can change the trajectory of their movement more than two dozen times. Perhaps that is why in the translation from the Turkic language its name means "diverge".
Habitat
In nature, there are more than 4 thousand species of these insects. Despite this diversity, the structure of cockroaches and lifestyle are similar: they all love heat and moisture. Therefore, most species live in the tropics. Some species have adapted to the cold climate of the northern regions, where they feed on moss and lichen. Cave cockroaches are also known that have lost the ability to see.
Synanthropus animals
According to popular belief, if cockroaches settled in the house - this is for wealth and prosperity. It is unlikely that those who at least once tried to get rid of these annoying insects will agree with this. Since ancient times, cockroaches settled in human dwellings. After all, he provides these animals with everything necessary: a constant temperature, moisture and food. Animals that settle with humans are called synanthropes. In addition to this species, these include ticks, flies, mosquitoes, mice, pigeons, ants.
The external structure of the cockroach
A distinctive feature of this type of insect is the oval shape of the body. Its sizes vary from 2 to 9 cm. The head is triangular and flat. In front, it is protected by a pronotum. There are eyes on the sides of the head, which allows these creatures to see in all directions.
A distinctive feature of the structure of cockroaches are the oral organs of the gnawing type. They consist of paired upper and lower jaws and two unpaired lips. This type of oral apparatus is designed to grind any kind of food. This is possible due to the presence of numerous chitin teeth on the jaws. On the head there is also one pair of bristle antennae.
The thoracic region is represented by three segments, which are attached to a pair of legs. Extremities of a traveling type. Each leg consists of five segments and ends with claws. This structure allows cockroaches to move even on steep surfaces.
Wings are located on the chest - double lamellar folds of the integument.
The structure of the wings of cockroaches has its own characteristics. By origin, they are double lamellar folds of covers. Outside, they are protected by dense elytra, which have tube-like thickenings - veins. These structures perform a supporting function. The wings are thin, mesh. In some species, the aircraft is reduced.
The abdomen of cockroaches consists of 8-10 segments. In each of them there are nerve nodes and spiracles - holes with which the trachea opens outwards. This structure explains the fact that cockroaches can live without a head for a long time.
The abdomen ends with a special structure - the church. Visually, it resembles a bristly mustache. Its presence is proof of the ancient origin of cockroaches. By the structure of the abdomen, you can determine the sex of these animals. The males have a genital plate, but the ovipositor of the females is located inside the body.
The outer skeleton of cockroaches is represented by a cuticle. The middle layer of this substance contains pigments that determine the body color of insects. Cockroaches can be black, red, white, tan.
Features of the internal structure
Cockroach organ systems are typical of insects. The muscles are well developed, able to contract with high frequency. For example, an American cockroach is able to overcome a distance of 75 centimeters in a second. On the extremities of these insects are thin hairs that perceive even the slightest movement of air. Therefore, cockroaches are difficult to catch.
Digestive system of the through type. In cockroaches, the structure of its organs has the same plan as in all arthropods. But all insects have salivary glands, and the liver is absent. The organs of the digestive tract include the oral cavity, the hypopharynx, pharynx, esophagus, goiter, muscle stomach, intestines. From the last section, undigested products enter the excretory system, which is represented by malpighian vessels. The presence of goiter and the complex process of the breakdown of organic substances allows cockroaches to live without food for several weeks.
The circulatory system is open. It is represented by a tubular heart and a single vessel. The blood is colorless. It mixes with the abdominal fluid, forming a hemolymph. Such a primitive structure is explained by the fact that the respiratory system, represented by spiracles, performs the gas exchange function. There are ten pairs in all.
What is a fat body?
The internal structure of the cockroach is characterized by the presence of loose connective tissue in the body cavity. It is called a fat body. This tissue occupies the entire space between the internal organs.
Fatty cells are trophocytes. Their cytoplasm contains various inclusions. Due to this structure, this tissue is involved in metabolic processes, the accumulation of fats, carbohydrates, calcium compounds.
Uninvited guests
The structural features of cockroaches and physiology are determined by their favorite habitat - the human home. There are all comfortable conditions: heat, water and darkness.
A feature of the structure of the cockroach squad is their omnivorousness. Their favorite treats are bread, sugar, cereals, vegetables and fruits. But if these products cannot be included in the diet, cockroaches can eat paper, fabrics, glue, book binding, any garbage. Moreover, parasites do not completely eat the product, but bite it and look for something more tasty.
Getting rid of cockroaches is often quite difficult. They are clogged into the smallest cracks, cracks, cavities in the wallpaper or ceramic tile. Therefore, it will be necessary to treat with chemical preparations all inaccessible places.
Breeding
Cockroaches are dioecious individuals with noticeable sexual dimorphism. The latter is manifested in morphological differences between males and females. Everyone can identify them. The male is smaller. Its wings are better developed, which allows you to fly over short distances. The last segment on the abdomen of the male has specialized outgrowths, which are called lead pencils.
The structure of cockroaches determines their ability to internal fertilization. After mating, the female lays eggs covered with a protective shell - edema. For cockroaches, an incomplete transformation is characteristic . This means that larvae emerge from the eggs that look like an adult insect. It is called an imago. First, the larva is devoid of wings. It grows, molts and develops into an adult insect. This period lasts about four weeks. Individuals become sexually mature only after three months.
Cockroaches are very prolific. Throughout her life, one female produces more than one hundred individuals. It carries out laying of eggs repeatedly. And for this, she does not have to constantly mate. The fact is that sperm can be stored for a long time in the female reproductive ducts.
Species diversity
Like all insects, cockroaches are characterized by significant species diversity. A typical inhabitant of human dwellings is the Prusak, or ginger cockroach. The structure of these insects is not very different from the above. There is an opinion that a red cockroach was brought to our country by soldiers who were returning from Prussia. Hence the second name of this parasite.
The structure of the black cockroach is more impressive in size. Individual individuals can reach 5 cm in length. For humans, they can be quite dangerous. Getting into his house from garbage cans and sewers, on the extremities they bring eggs of other parasites and pathogens.
White cockroaches are not fiction. This kind really exists. They acquire such unusual color for these insects as a result of molting. Over time, they darken.
A special type of cockroach is furniture. It has a bright red color. The wings of such an insect are transparent, brown stripes are located on them. His favorite delicacy is starch and everything that contains it. This is mainly wallpaper glue and book bindings. Therefore, they do not settle in the kitchens, but in libraries and archives.
The most common species in the south is the Central Asian cockroach. It can be recognized by the yellow head and dark abdomen. They jump high and are able to fly over short distances. It is almost omnivorous and feeds on the remnants of food, plants and sewage.
So, a feature of the structure of cockroaches is the presence of three parts of the body, a dense chitin cover, six walking legs and a pair of wings. These insects are synanthropic animals. This means that cockroaches prefer to settle in human dwellings. Here for them there are all comfortable conditions: heat, moisture, darkness and a sufficient amount of food waste.