Features of the structure of the cockroach, the secret of survivability is revealed. Circulatory, respiratory and excretory systems of a black cockroach Internal structure of a black cockroach side view
Cockroaches and many other insects have long been human companions. They happily coexist in houses and apartments with people, causing them trouble. For example, the bulk of cockroaches love to live in the wild, but some species prefer to settle in people's homes. The black cockroach is considered a pest, so it must be disposed of immediately. To make it easier to deal with such a pest, you need to know what a black cockroach is.
The black cockroach belongs to the cockroach order. Representatives of this species are quite common in European countries. It also lives in Africa and Asia and is the closest relative of the eastern cockroach. However, these cockroaches are less common than their red counterparts.
You can keep your house perfectly clean, but due to the carelessness of your neighbors, cockroaches still spread throughout the house. Since representatives of this type of pest reproduce very intensively, they are forced to constantly look for new food. Favorable factors for their development are:
- garbage in the house;
- unwashed dishes;
- sewer drains;
- garbage collectors;
- dampness in the bathroom.
Black much larger than their red counterparts, their sizes reach 5 cm. The chitinous shell covering the body of a black cockroach has a black or dark brown color. The outer cover of the body is quite durable with a brilliant sheen, so in order to completely crush the insect, you need to make an effort. Its body is flat, and this allows the insect to easily penetrate into the smallest cracks and cracks in the wall and floor. The body is divided into three sections:
- head;
- breast;
- abdomen.
The segments forming the head section are fused together. On the sides of the head are two large eyes. An interesting fact is that males have much better vision than females. Small jointed antennae, resembling antennae, continuously perform oscillatory movements. Mustache length is responsible for touch and vibration, and in the male their length is greater than in the female. His mustache is much longer than his body size.
In the thoracic region there are three pairs of legs that serve the insect for running and walking. The last two legs have wings. In the female, they are shortened, so she does not know how to fly.
The abdomen of a cockroach consists of 10 segments, they are attached to the chest without constriction. Powerful mouth organs consist of the upper and lower lips and jaw. With the exception of the upper lip, all other parts of the oral cavity can be modified. The oral cavities of a cockroach are primitive, gnawing type. The insect easily gnaws and consumes solid food.
Digestive system and respiratory organs
consists of several departments:- oral opening and oral cavity;
- pharynx, esophagus, goiter, chewing stomach;
- midgut;
- hindgut and anus.
Absorption and digestion of food occurs with the help of special blind outgrowths. They are located between the stomach and the midgut. Since cockroaches are omnivorous insects, they eat a variety of food and even their own brethren. They have a well-developed powerful mouth apparatus. The remains and waste of products, as well as indoor plants, book bindings, leather things are used as food.
The respiratory system looks like thin tubes called tracheae. They originate on the sides of the abdomen in the form of small holes. Small tracheas branch throughout the body of the cockroach and deliver oxygen to all internal organs and tissues of the insect. Carbon dioxide is removed outward through the trachea. To ventilate them, cockroaches periodically shrink their abdomen.
The nervous system of a cockroach is a large supraglottic ganglion, a subpharyngeal ganglion and an abdominal nerve chain. From the main nodes, nerves depart to the eyes and other well-developed sense organs.
Habitat and reproduction
Black cockroaches are in many ways similar to ordinary Prussians and love to settle next to a person. Prefer to dwell in damp and warm places, because they cannot do without water and constantly need warmth. In hot countries, pests live and breed outside the living quarters. Insects are nocturnal, they die at temperatures of 0 ° C and below.
In the conditions of an apartment, preference is given to;
- bathroom;
- kitchen;
- shared bathrooms.
Pests feel great in nooks hidden by interior items, behind heating radiators, in cases of household appliances, under sinks.
Black cockroaches live from several months to 3-5 years. The entire life cycle of an insect consists of three forms of development:
- egg;
- nymph;
- imago.
Mating takes place during the warm season, after which the females lay their eggs in a chitinous cocoon. There they mature to the desired state. There are approximately 16 eggs in this organ. While the female carries eggs, and her abdomen increases slightly in size, but after a while she leaves them in a secluded place. Whole incubation period is 44 days after which the larvae appear. In color, they bear little resemblance to black cockroaches, but as they grow older, individuals become much darker.
What are dangerous and where do cockroaches come from
Since cockroaches, including black ones, come to houses and apartments from unsanitary places, they carry many pathogens with them. They are considered carriers of dangerous infections:
- dysentery;
- typhoid fever;
- helminthiasis;
- diphtheria.
These insects harm people's property spoil and contaminate food. Gnawing through the insulation, they disable household appliances, since their oral apparatus is well developed. They are able to bite a person in a dream, especially for children, when there are a lot of cockroaches in the house.
They can get into people's houses in several ways. Most often this happens when people bring things home. For example, coming from a business trip or coming from guests, you can easily bring things with cockroaches into the house. Most often, cockroaches penetrate the lower floors of multi-storey buildings. There are often cafes, shops or restaurants on the ground floor. When in such establishments they begin to fight insects, they, escaping, begin to run away through the ventilation system.
Cockroaches love to move around. garbage chutes and sewer pipes, so they often get into people's homes in such ways. If they appeared in the house, then this place is comfortable for them. They are attracted to unwashed dishes, a full trash can, a dirty sink, and high humidity.
Fighting methods
In ancient times in Russia, black cockroaches in the house were associated with prosperity and wealth. At that time they were protected and not destroyed, but now much has changed, and people began to fight them using various methods of destruction.
Kitchen cockroaches are more difficult to deal with than Prussians, because they more agile and resilient. There are several types of pest control. Preventive measures are the simplest of them. This consists in the constant observance of the sanitary and hygienic rules for maintaining the dwelling.
The chemical method is more effective. You can use various chemicals that are now offered in a large assortment. The third proven method is the use of folk remedies. They are effective only when insects have recently appeared in the house, and there are still a few of them.
Black cockroach- lat. Blatta orientalis, a member of the phylum Arthropoda, belongs to the class Insects. The black cockroach is a domestic invertebrate animal; it differs from other representatives of this family in larger forms. A feature of the black cockroach is the rapid adaptation to a new environment. Also, the black cockroach is able to move very quickly and be "invulnerable".
Black cockroach: Order cockroaches - Superorder insects with incomplete transformation - Infraclass winged insects - Subclass open-jawed - Class insects - Type arthropods.
Structure
The body of this insect consists of three sections: the head, chest and abdomen. The head consists of 4 fused segments, covered with a nitrogenous shell - chitin. The head has complex and simple eyes, antennae (long and thin) and mouth appendages. The mouth apparatus of the insect is of the gnawing type.
The chest of a black cockroach is divided into three sections or segments. The chest consists of two pairs of wings and three pairs of legs. The first pair of wings has a leathery structure. The second pair is membranous. The wings of the female black cockroach are underdeveloped. The chest of a black cockroach is also covered with a chitinous cover.
The abdomen of a black cockroach consists of 10 segments. The insect has no limbs on the abdomen, except for one pair of styli, which is located on the last segment of the black cockroach.
Characteristics of the animal:
Dimensions: male length 2 - 3 cm; female length 1 - 2 cm.
Fertility: the female black cockroach bears 20-30 offspring during her lifetime.
Color: The body is dark black or black-brown with a metallic sheen.
Nutrition
Black cockroaches feed on everything that comes across, in particular flour products, plant foods and other products, as well as the remains of invertebrates. As a result, due to their long antennae and, in general, the whole body, on which many microbes are stored, black cockroaches are carriers of many diseases.
Reproduction and habitation
Black cockroaches are dioecious animals. During the fertilization period, the abdomen swells in females, where a kind of pouch or ootheca for laying eggs. The eggs in the ootheca are arranged vertically and in several rows. The female black cockroach wears the ootheca for only a few days, after which it hides it in a place inaccessible to other insects. After a while, many small white cockroaches appear from the ootheca, which develop from 1 to 4 years, depending on living conditions.
Black cockroaches are synanthropic animals, that is, their lifestyle is closely related to people's housing. Therefore, black cockroaches can only be found in residential buildings, mainly in the territories of most European countries.
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Greetings dear readers of my blog. In today's article, we will consider the structure of a cockroach and the physiological features of this insect. Just imagine - there are more than 7,000 species of cockroaches on the globe, and the most common in our latitudes are the red and black cockroach. It is about them that will be discussed in this article.
The external structure of a cockroach
Despite the huge number of species, all insects of the cockroach order have a similar structure. The main differences are usually the size and color of the insect, but the internal anatomy is almost the same in black and red cockroaches.
Nature gave these creatures an excellent tool for crawling into the gap under the densest plinth - an elongated and flat body. It is divided into the abdomen, chest (which consists of the prothorax, middle and metathorax) and the head. In addition, each insect has a pair of wings. Did you know that cockroaches can fly? Below I will tell you how the wings of this creature are arranged, what importance the wings have for the reproduction of offspring, and why only males can fly.
Head
I propose to start studying cockroach anatomy from the head, which in most individuals is quite large and has the shape of an oval or a rounded triangle. From above, it is covered by a shield-shaped anterior segment of the chest, from under which only the back of the head is visible, and the rest of the head is turned downwards.
Eyes
On the sides of the head are paired compound eyes, and on top are two simple ocelli, which are poorly developed in most species. By the way, due to the peculiarities of the structure of the eyes, cockroaches see the world around them as a mosaic assembled from thousands of small multi-colored pieces. And although such vision does not allow distinguishing the details of an object, the so-called perception of light flickers in a cockroach is 5 times higher than a human one.
That is why it is so difficult to overtake an insect with a slipper or a newspaper - even the fastest person for cockroaches is like a fly stuck in jam. In a word, if you have ever asked yourself why these creatures almost always manage to avoid reprisal, now you know the answer.
tendrils
In children's horror stories, the cockroach is always depicted as a mustachioed monster, and it is not for nothing that the mustache is given so much attention. It is the antennae that are the organ of thermal sensitivity, touch and smell. They are also used as a means of communication between individuals: by touching their whiskers, cockroaches exchange information. The whiskers are of considerable length and covered with bristles, the number of which increases with each molt and reaches 80 pieces by the age of maturity. 
Mouth
Despite their small size, the bites of the red and black cockroach can be palpable and even painful. The fact is that the mouth apparatus of these creatures belongs to the gnawing type and has a rather complex structure, and each part of it has its own special purpose:
- labrum, or upper lip - articulated with the head in a movable way, covered from the inside with receptors that analyze the composition of food;
- mandibles, or lower jaw - curved, rather massive plates covered with sharp teeth, their purpose is to hold a piece of food;
- maxilla, or upper jaws - located above the lower jaws, necessary for grinding food and chewing;
- labium, or lower lip - surrounds the mouth apparatus from below, prevents food from falling.
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Outside, on the lower lip there are special receptors (tactile and taste) that are necessary for searching, detecting and analyzing food.
In addition to the complex jaw, the insect's mouth contains a salivary gland and a tongue-like organ that helps absorb fluid. As you can see, the cockroach's mouth apparatus is an ideal tool for finding and destroying bread crumbs, even in the cleanest kitchen. No wonder this type of insect is considered the most tenacious. 
Breast
On the chest of cockroaches are wings, elytra and three pairs of legs. The breast consists of three segments, the largest of which is the first - the so-called pronotum. On the sides of this convex hexagonal segment there are depressions where the elytra are placed. Most often, the pronotum has a lighter color compared to the rest of the body, and in some species this part is even transparent.
Legs
As for the paws of the insect, they are located on different segments of the chest, consist of five parts and are called "five-segmented." On the upper four segments of the legs there are pads, and on the lower there are claws, between which there is also a suction cup.
This structure of the paws helps the insect to easily move on any surface - both horizontal and vertical. Moreover, on the paws of this creature there are the smallest hairs that catch even the slightest fluctuation of the air, due to which the cockroach reacts with lightning speed to a moving object.
Strong legs allow you to develop a high speed for such a small size - a cockroach is able to run at a speed of 3-4 km / h. If this figure is not surprising, imagine this: if a cockroach was the size of a cheetah, it could easily catch up with a feline.
In addition, the peculiarity of the legs determines the high maneuverability of the insect: cockroaches are able to change the pattern of movement with lightning speed. Depending on the location, each pair of legs has its own special purpose:
- the prothoracic legs are shorter than all the others, they serve as a kind of brake at a high speed of a cockroach;
- mid-sternal legs are responsible for high maneuverability, as they are able to move in different directions;
- the hind legs are longer than the other two pairs, move the body of the cockroach forward and are the main walking limbs.
Wings
Two pairs of wings are attached to the breast of a cockroach. Above are rigid elytra, designed to cover the abdomen and thinner wings. Interestingly, the length of the wings of the male significantly exceeds the length of the wings of the female. Cockroaches use their wings to accelerate while moving and also to slow down when falling.
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Fortunately, only one species of all cockroaches can fly, but the rest of the wings will be useful for mating games. That is why the wings of the male are longer: during mating, the spread wings form a convenient platform for a larger female.
Abdomen
The abdomen of a cockroach has 11 so-called tergites (segments), but only 8-9 can be distinguished. The tenth segment forms a plate that covers the anus. In females, the abdomen continues with an ootheca - eggs are stored in this segment (about 12-16). This part of the body has the shape of an oval, and due to its impressive size it is always noticeable and is an obvious difference between the female and the male. It is noteworthy that with sufficient nutrition, the female is able to produce ootheca every two to three days. 
The internal structure of a cockroach
Surely you have heard that cockroaches can live without a head for a whole week, or even a month. But you hardly know what physiological features make this possible. Below I will talk about how these amazing insects are arranged from the inside, and why cockroaches feel great even after they have been decapitated.
Digestive system
We already know how the jaws of a black and red cockroach are arranged, but what happens to the food next? As I said, salivary glands are located in the mouth, which secrete saliva, designed to soften and moisten food before swallowing. It is noteworthy that what is eaten is partially digested already in the goiter of the insect, and the stomach will take care of everything else.
Thanks to its muscular structure, it sort of "grinds" food, sending it then to the middle intestine, then to the back intestine and into the excretory system. The intestines of cockroaches are inhabited by bacteria and fungi, thanks to which the insect is able to digest even inorganic compounds.
Interestingly, the cockroach does not need to chew food too thoroughly - in the part of the foregut, located just behind the mouth, there is a row of teeth, which will surely crush the food swallowed in a hurry.
Cockroaches do not have a urethra, so both feces and urine are excreted through the anus.
Circulatory system
The circulatory system of cockroaches is of an open type, and the blood of these creatures is white and is called "hemolymph". Blood circulates freely within the body, washing all internal organs. The movement of the hemolymph is due to the work of the heart, and the speed of blood circulation is very slow, making the cockroach very sensitive to ambient temperature. 
Respiratory system
The cockroach breathes with the help of spiracles - these are 10 pairs of small holes that are located on the sides of the abdomen. The spiracles continue with tracheoles - tubes that form a system and connect into six large tracheal trunks. This structure of the respiratory system allows a diffuse way to supply oxygen to all internal organs.
