Blatta orientalis - so in Latin it is called Black cockroach. The genus to which this insect belongs does not have many species. The closest relatives of the Eastern cockroach (this is another name of the insect) live on the Australian and African continents. Himself spread throughout the world and already more than three centuries ago, firmly established in Europe.
Today, the big black cockroaches, presented below in the photo , are found in apartments much less often than their red-haired brethren:
But in the old days in Russia it was black cockroaches who lived in cellars and closets, looking after the master's good. Moving to a new house, it was customary to take these insects with them for luck. It was believed that when there are cockroaches in the house , then the people living in it do not have anything to do.
The life of a black cockroach
Once upon a time, many insects "understood" that it was more comfortable for them to live near people. Black cockroaches, capable of reaching large sizes, prefer raw basements, sewage, garbage collectors. They do not mind doing business in grocery stores, public catering places, hospitals and prisons.
In apartment buildings, the residents of the lower floors suffer most from them, since uninvited guests do not rise above the fifth floor.
Black cockroaches are synanthropic insects, which, of course, can quite safely exist outside the human dwelling, but still try to stay close to it, searching for secluded places under stones or in cracks of old buildings. You can see them in nature in the southern regions, on the Black Sea coast.
While it is light, insects try not to leave their shelters, and at night they boldly go out in search of food. Representatives of this species are omnivorous, they do not disdain any products and remains of invertebrates.
The appearance of a black cockroach is of interest, first of all, for people enthusiastic about entomology. Here is an example of a photo of these insects:
But the presence in the house of such a handsome man of rather impressive size is not all inspiring. The length of the female is slightly larger than that of the male, and can reach 3 cm. It is said that the sizes of individual individuals approach 5 cm.
The insect has a chitinous shell of black color according to its name, rarely it is brown. Covers are gleaming like metal, and are quite strong, therefore, in order to crush an insect, you need to make an effort. The cockroach is flat, which allows it to easily penetrate into the narrowest cracks.
Parts of the body of the Black cockroach
The body of the Black cockroach, a typical representative of the Insect class, is segmented into three divisions - the head, chest and abdomen. Segments forming the head compartment are merged together.
On the sides of the head are two large eyes that have a complex facet structure. Moreover, in the case of a male, the sight is sharper than that of females. A pair of articulate antennae is located in front. The insect during the movement exposes them forward and to the sides. Antennae, reminiscent of small antennas, continuously oscillate. The length of the mustache responsible for the sense of smell and touch is larger in the male than in the female, and exceeds the size of its body.
The chest of a black cockroach is represented by three segments - the prothorax, mediastrum and metathorax. The dorsal region of the first segment is highly developed, hanging forward, hiding the head of the insect. To each segment on each side is attached a pair of running legs.
The last segment of the cock of the foot carries a pair of claws and a sucker, so that the insect can move on any surface, including the vertical one. On the chest of a male black cockroach - two pairs of wings (see photo):
The soft abdomen of black cockroaches is formed by ten segments, the first seven are larger, the others are reduced, and this is more pronounced in the female. On the last segment there is an anal opening, and on the sides there are two small sensitive limbs - cerci. The ninth segment of the male is carrying pencils, which serve as protection for its external genital organs.
It is interesting
Although the middle part of the body has a pair of leather elytra, and the back part - two real membranous wings, they are not used for their intended purpose. Female black cockroaches are completely devoid of devices for flying, they have only elytra, and they are in embryo.
Eight segments of abdomen and two infants are equipped with respiratory apertures, or stigmata. From them inside the body of the insect there is a branchy network of tubes - trachea, entangling all internal organs and ensuring the delivery of oxygen to them.
A cockroach has a multi-chambered heart that specifies the directed movement of fluid from the posterior end of the body forward, and the aorta. Hemolymph washes all internal organs.
The nervous system of the cockroach is interesting. It is represented by a chain of nerve nodes, the largest of which, the supra-pharyngeal, performs the function of the brain, provides innervation of the main sense organs.
The digestive system of the Black cockroach
The oral apparatus is located below, it is concentrated around the pharyngeal opening and is arranged quite intricately. It is represented by the upper lip - an outgrowth resembling a tongue, as well as a pair of upper and two pairs of lower jaws.
The structure of the lower jaw includes another sense organ - the tentacles. Oral parts of the cockroach gnawing type, they are powerful, cope with a variety of food: both liquid and solid. The digestive system of the black cockroach is formed perfectly.
The food is crushed by jaws and moistened with saliva, processed throughout the intestines by digestive enzymes, subjected to additional mechanical action in the so-called chewing stomach , which has folds in the form of chitinous plates, and also to the action of specific bacteria that colonize the intestine of the cockroach. All this allows the insect to digest products that seem us inedible.
Nutrients and decay products move in the body of a black cockroach by means of hemolymph.
Three lives of the Black cockroach
Cockroaches are a detachment with incomplete transformation, and this means that they have only three qualitatively different forms of life - the egg, the nymph, the imagos.
Sexually mature female and male mate, then in the genital cavity of the female, which is under the dorsal shields of the last segments of the abdomen, an ootheque, a peculiar chitinous cocoon is formed, where the eggs will ripen. The ooteca near the black cockroach, which can be seen on the picture below, is large, up to 12 mm in length, dense, 16 eggs are usually packed in it.
At this time the belly of the female grows slightly in size, for several days, taking care of the offspring, the cockroach bears ootec with itself, and then leaves it in a secret place. The stage of incubation lasts up to 44 days, then larvae appear from the cocoon, small copies of black cockroaches, but their coloring is much lighter than in adults, they are almost white.
The larvae undergo up to 10 lines before reaching puberty. Becoming older, the nymph is more like a parent.
The temperature of the environment affects the reproduction of cockroaches and the rate of maturation of the offspring. In conditions of human habitation the reproduction of cockroaches does not interfere with anything, therefore they breed all the year round. Can pass from one year to four, while the younger generation will be ready to mate. During all life the female lays 2-3 cocoons with eggs.
Harm caused by cockroaches
Black huge cockroaches most often come to human apartments from the most nasty places - garbage cans, sewerage, they drag the pathogenic microorganisms and helminth eggs on the paws of the feet, they clog up the room with the products of their vital activity - excrement, chitinous coverings left after molting.
They not only spoil the appearance of housing, but also are capable of causing serious harm to human health, since they provoke the occurrence of allergic reactions, including pronounced ones.
What can be the benefit of the Black cockroach?
Talk about the benefits of a black cockroach, even a photo of which many people can cause a fastidious reaction, may seem inappropriate. However, the powder and tincture, made on the basis of large black cockroaches, according to some, have amazing healing properties.
This tool is appreciated by representatives of Oriental medicine, it was developed in the previous centuries by sorceresses, and its virtues were believed by well-deserved doctors. They say that Botkin himself appointed him to the patients.
This medicine is recommended for many troubles: some are advised with it to get rid of worms, others are used as a diuretic, others, paradoxically it sounds, try to stop using it asthma attacks. It is difficult to say how effective this remedy is, because modern official medicine is categorical in this matter and does not recommend self-medication.
Nevertheless, the facts of using black cockroaches for a variety of potions and tinctures have a place to be. However, how serious should be the health problems of a person, and how unacceptable for him should drugs appear that are sold in pharmacies, so that he avoids disgust, gave preference to such an unusual and not the cheapest method of treatment?