Red cockroach — bosom enemy of housewives, nocturnal defiler of kitchens and bathrooms. It’s the insect of childhood, our squatter lodger, travel companion, hotel roommate, and office mate. They have been trying to kill him for centuries, but he just as stubbornly resists, changing tastes and susceptibility to poisons. This is a universal soldier of nature, guarding its main law – survival at any cost.
Origin of the species and description
The red cockroach, also known as the Prussian cockroach (Blattella germanica), belongs to the Ectobiidae family. It was described by Carl Linnaeus in “The System of Nature” in 1767. The name of the genus comes from the Latin word “blatta”, which the Romans called insects that were afraid of light.
Ectobiids, or tree cockroaches, are the largest cockroach family in which about half of all cockroaches from the order Blattodea. But apart from the Prusak, among them there will be no more than 5 pests like him, occupying people’s houses. The most famous of them are black and American. The rest prefer a free life in nature.
Video: Red cockroach
In the structure of cockroaches, primitive signs characteristic of ancient insects can be traced: chewing jaws, poorly developed flying muscles. The time of their appearance, judging by reliable prints, dates back to the beginning of the Carboniferous (about 320 million years ago). Phylogenetic analysis shows that cockroaches arose earlier than — at least in the Jurassic.
An interesting fact: National antipathies are reflected in the popular names of an unpleasant insect. In Russia, this type of cockroach is called “Prussian”, because it was believed that it was imported from Prussia. And in Germany and the Czech Republic, once part of Prussia, it is called “Russian” for a similar reason. In fact, it is not known where he appeared before. Historical migration routes of the red beast have not been studied.
Appearance and features
Cockroaches are insects with an incomplete transformation cycle and go through three stages as they develop: egg, larva (nymph) and adult (imago), and the larva differs little from the last stage. The larva hatches from the egg after 14 — 35 days and passes from 6 to 7 molts, each time increasing in size, until it reaches the size of an adult cockroach. This process takes from 6 to 31 weeks. The adult male lives 100 — 150 days. The lifespan of a female is 190 — 200 days. The cockroach is agile, sneaky, elusive and disgusting, especially at the last stage.
Adult Prussians are 12.7 — 15.88 cm and weight from 0.1 to 0.12 g. The general coloration is light brown, two wide dark stripes run along the dorsal side of the prothorax. The chitinous lacquered cover is thin and the body is soft, which enhances the aversion to this insect. The shape of the body is streamlined, oval, flattened and adapted to slip into any gaps.
The thoracic segments smoothly pass into a segmented abdomen, which is covered by paired soft wings. When frightened, the cockroach spreads its wings, but is only able to use them for gliding, for example, from the table to the floor. Spiked legs are long and strong – the legs of a real runner. The neat, flattened head is adorned with a flexible, thin mustache, which the Prussian warily moves around, trying to catch the danger.
Males are more slender and narrow than females, the narrowed end of the abdomen sticks out from under the wings and is equipped with two protruding bristles – cerci. In females, the end of the abdomen is rounded, usually it carries eggs in a special package – ootheca. Larvae are nymphs smaller, but of the same shape. The coloration is darker, the stripe is one and the wings are underdeveloped. The eggs are round and light brown.
Where does the red cockroach live?
South Asia is the recognized homeland of the Prussians. Their mass distribution begins in the 18th century – the era of round-the-world travel, scientific expeditions and colonial trade. Now red cockroaches have dispersed all over the world and populated all suitable habitats, not embarrassed by the presence of local relatives. Some, for example, the European black cockroach, they even managed to displace from their established ecological niche.
By nature, a cockroach is an inhabitant of the tropics, a lover of a warm climate and freezes when the temperature drops below -5 C °. Under natural conditions, he does not live outside the zone with a frost-free climate, in the mountains above 2000 m, as well as in too dry regions, such as deserts. Only cold and drought prevent him from conquering the whole world, although, using the comfort of human dwellings, he is able to advance even in the Arctic.
Due to the versatility of tastes and undemanding food, the Prussians inhabit any heated premises in cities and rural areas, both private and public. Especially if there is an abundance of food and moisture, as in kitchens and bathrooms. Prussians in hospitals and catering establishments become a real disaster. Urban housing stock with central heating and running water suits them perfectly. Within the home, they move through the ventilation system and garbage chutes, and often use suitcases or furniture to move to new places.
An interesting fact: One of the effective ways to get rid of our smaller obsessive brothers is to freeze the premises. Therefore, cockroaches never settle in summer cottages.
Now you know that you can meet a domestic red cockroach in your apartment. Let’s see what these insects eat.
What does the red cockroach eat?
Red pests eat any inanimate matter containing organic matter. They even engage in cannibalism, eating their dead counterparts. Dumps and other places where human waste accumulates, farms, greenhouses, canteens, hospitals, nature museums and herbariums, library book depositories, archives and warehouses serve them as a table and a home.
They are especially attracted:
- meat scraps and carrion;
- starchy foods;
- anything with sugar;
- fatty food;
- paper, especially old books;
- natural fabrics, especially dirty ones;
- soap and toothpaste;
- Natural glue, such as bone glue, used to make books.
The ability of cockroaches to absorb cellulose, like their closest relatives termites, is due to microorganisms that inhabit their intestines and, by digesting fiber, make it suitable for the host organism.
Interesting fact: While developing a universal poison for the Prussians, scientists discovered that they had bred a race that did not eat sugar and everything that contained glucose. Experimental insects reacted to glucose as something unpleasant and bitter. Such a race is an evolutionary response to the poisoned sugar baits that have plagued all sweet lovers. Only those cockroaches that neglected such a treat survived and multiplied.
Peculiarities of character and lifestyle
The Prussians belong to the so-called “synanthropic organisms”, which in life are closely connected with human society and live almost exclusively in the anthropogenic environment, people’s dwellings. Their resettlement to new territories also occurs with the help of humans – cockroaches travel with our things and food in the holds of ships, on trains, vehicles and airplanes.
After settling in the house, adults and their growing nymphs go out robbery at night. Although they are attracted to light surfaces in the dark, turning on the light causes the Prussians to flee instantly. This species itself does not make sounds, but the characteristic rustle of wings and legs that a fleeing flock makes is familiar to everyone who had the misfortune to live with them in the same apartment.
Cockroaches act very harmoniously, since certain relationships are established between members of the cockroach community that has occupied one room. They use scented substances — pheromones to signal the presence of shelter, food or danger, to transmit sexual signals. These pheromones are excreted in the feces, and running insects leave information trails here and there to guide their brethren to food, water, or mating mates.
Interesting fact: Scientists conducted an experiment to find out where pheromones are produced and what contain pheromones that collect cockroaches together. A group of Prussians were poisoned with intestinal microorganisms and it turned out that their droppings ceased to attract other individuals. After feeding on bacteria isolated from the faeces of untreated cockroaches, their excretions regained their appeal. It turned out that these bacteria are responsible for the synthesis of 12 fatty acids, which, evaporating in the air, serve as a signal for general gathering.
Social structure and reproduction
The Prussians are sociable and, when living together, create a real democratic society of equals, who are united not only by common housing and growing nymphs, but also by common interests. The main one is food, and cockroaches master the found edible together, ingenuously informing their fellows about its location and even quantity with the help of pheromones. The more cockroach tracks that lead to a food source, the more attractive it is to the rest. They are also free to choose a sexual partner.
Cockroaches breed very actively. During her life, the female lays from 4 to 9 packages (oothecus) up to 8 mm long, each of which contains 30 — 48 eggs. The formation of a capsule and the maturation of eggs in it takes an average of 28 days, and for almost all this time the female wears it at the end of the abdomen. Although, in the end, he can drop the load in a dark nook.
A few weeks later, she lays a new edema. In total, each female produces up to 500 heirs. Reproduction in a flock occurs continuously and all generations and stages of development can be present in it at the same time. In a good place, the cockroach population grows like a snowball or, in the language of mathematics, exponentially. Only cold weather or sanitization can slow down growth.
Interesting fact: Cockroach Nadezhda became the first animal to conceive in space. It happened on 14 — September 26, 2007 on the unmanned Foton-M 3 biosatellite. Cockroaches traveled in a container, and the fact of conception was recorded on video. Returning from the flight, Nadezhda gave birth to 33 cubs. The only unusual thing about them was that they grew faster than their earthly counterparts and acquired a dark color earlier. The grandchildren of Nadezhda did not show any peculiarities.
Natural enemies of the red cockroach
A cockroach is not poisonous and, in principle, can be eaten by any animal that does not disdain insects. But human housing provides him with a reliable shelter from birds and other free-living predators. Here he can be threatened only by other synanthropic homebodies and slaves.
- indoor birds;
- cats and dogs can catch them for fun.
The main enemy of the red Prusak is anyone under whose roof this malicious creature gets. With the fact that the insect causes considerable harm, any “green” will agree. It is enough for him to see his kitchen table after visiting them.
What is harmful to the Prussian:
- carries more than 40 pathogens of microbial and viral infections (including dysentery), which is especially important in hospitals;
- intermediate host of three species of helminths and protozoa;
- causes and provokes allergies, aggravates asthma;
- creates a stink in the room due to pheromones;
- spoils food;
- dirts things;
- acts on the psyche and can even bite.
Pest control measures have been improved for centuries. Isolating food waste and water, setting traps from which they cannot escape, freezing rooms, and finally, chemical warfare – all methods have been tried. Mechanical methods turn out to be ineffective, and chemical methods only lead to further improvement of the pest. Modern Prussians are not sensitive to pyrethroids – classical insecticides and are poorly susceptible to other old classes of pesticides. Modern drugs (hydroprene, methoprene) act as growth regulators and are more effective. They delay molting and prevent insect development.
An interesting fact: Previously, in houses, especially rural ones, titmouse and blue tit were brought in, especially to fight cockroaches. The birds spent the winter warm, cleaned the house from pests, and in the spring, according to tradition at Easter, they were released.
Population and species status
No one counted how many Prussians are in the world. Everyone is only interested in their becoming smaller. But for now, it remains a dream. While the Prussian is successfully improving in parallel with the improvement of methods of struggle, its status can be confidently defined as “increasing numbers”.
The number in a particular region can fluctuate greatly. Either cockroaches practically disappear after sanitization, or there are so many of them that they begin to walk around in the middle of the day. The population explosion may seem sudden, if you do not know that the number of Prussians is growing exponentially according to the law of Malthus, that is, slowly at first, and as the number increases faster and faster. According to Malthus, only famine, epidemics and wars can limit it. An English economist was deriving his law for mankind, but cockroaches serve as an excellent model for demonstrating his action.
Famine and epidemics do not threaten the Prusak. Mankind wages constant wars with them. Scientific articles are reminiscent of battle reports, discussing the development of strategies, the loss of the enemy, the reasons for failure. On the other hand, studies confirm that it is people who spread the Prussians, transporting them on vehicles and creating new places to live: greenhouses, heated farms, warm storage rooms. So over the past 20 years, the Prussians have become annoying pests on US pig farms. A genetic study showed that they are not distributed centrally – from the management company, but are transferred by employees of neighboring farms. The Prussian will prosper as long as this vicious cycle continues.
There are few animals that enjoy being near people and the red cockroach is one of them. The problem is that people do not need such a companion at all. Will it be possible to get rid of it, or will they learn how to use it in the household to mutual pleasure? These questions remain unanswered.