Cockroaches: life, types and curiosities. Meet this insect

Whether out of fear, disgust or the possibility of acquiring any disease transmitted by this insect, the truth is that the cockroach is seen with some disgust by human beings.

Despite this, this pet is present in the city and in the countryside, in houses and apartments, the versatility of the species makes it present in the daily lives of people who lead different types of life. And from now on you will have the opportunity to know more about him.

Characteristics of cockroaches

Cockroaches are insects and have inhabited planet Earth for approximately 380 million years. They show nocturnal habits when looking for food and partners. For the rest of the day, they are hidden in their habitat to mate. They do not organize themselves into society, having a solitary habit.

Most cockroaches have six legs, two antennae and a pair of wings (Photo: depositphotos)


Cockroaches live in places with hot and humid characteristics, such as: sewage networks, abandoned land, places with garbage, manholes, messy and dirty environments. In forests, they can be found under rocks and inside bark of trees.

What they eat

They usually enter homes in search of food, since they eat food scraps , especially sweets, fatty foods and animal products. They are, therefore, considered omnivorous insects , because they feed on what they find.

Physical characteristics

Its body is oval, flat and brown in color and most species have six legs, a pair of wings and a pair of antennae. It measures from 5 millimeters to 10 centimeters, and females are usually larger than males.

Cockroaches reproduction

Cockroaches reproduce sexually , where the female produces eggs and the male fertilizes them. In general, mating between cockroaches begins with males being attracted to sexual pheromones emitted by females. When the meeting takes place, the couple initiates physical contact.


The mating of this insect begins when the male raises its wings, leaving exposed a gland located on the dorsal surface of the abdomen. This gland is responsible for excreting a substance that the female feeds on. While the female climbs on the male to feed on this substance, underneath, the male introduces his genitalia into the female’s genitalia, and thus starts copulation .

Life cycle

This group of insects presents incomplete metamorphosis , passing through the egg, larva and adult stages, with the absence of the immobile stage (pupa). In most species, eggs are contained in a case called an ooteca. This structure, depending on the species, can vary in terms of shape, size and number of eggs. During her life, a female can lay an average of 225 eggs.

How long does a cockroach live?

Cockroaches can live from six months to three years, depending on the species.

Types of cockroaches

There are about four thousand species of cockroaches in the world. In Brazil, there are 644 different species and most live in forests. Few species are considered synanthropic, that is, they live associated with the human environment.

Of these, the most well-known species are: Blattella germanica , Supella longipalpa , Periplaneta americana , Periplaneta australasiae.

Blattella germanica

It is also known as kitchen cockroach, German food or German cockroach. As an adult, it varies from 10 to 15 mm in length, without the antennae. The male has a yellowish brown color and the female is slightly darker.

It is cosmopolitan, being considered a household pest and the one that most spread around the world. This cockroach urban lives in dark and high humidity environments, preferably in kitchen cabinets and bathrooms, but it can also be seen in places that have some type of food and water. Females carry the ootheca at the end of the abdomen until the nymphs are born.

Supella longipalpa

It is also known as closet cockroach, francesinha or striped cockroach. As an adult, it varies between 10 to 14 mm in length, without the antennae. Males are more slender, with wings extending beyond the abdominal extremity. Females have a more robust appearance, with shorter wings leaving the tip of the abdomen visible.

This species of cockroach is considered a pest of circumtropical distribution, that is, in both tropics. It is home and lives in dark environments and, unlike Blatella germanica,  can be found in all rooms of a residence, having no preference for kitchens or bathrooms.

American Periplaneta

It is also known as sewer cockroach, flying cockroach, American cockroach or red cockroach. The adult varies between 40 to 50 mm in length, without the antennae. It is the most common urban species in hotels, residences and restaurants.

It has a circumtropical distribution, occurring in all regions and cities in Brazil. He prefers dark, hot and humid environments, accepting any type of food. Very common to be found in sewers, pipes, pits and latrines. It has nocturnal habits, but its occurrence during the day is an indication of overpopulation.

Periplaneta australasiae

This species of cockroach is easily confused with the American Periplaneta , although the adult is slightly smaller. Although the scientific name indicates its origin in Australia and Asia, it is a cosmopolitan species. The adult varies between 30 to 35 mm in length, without the antennae.

Males and females have a reddish brown color, with a narrow yellow band at the base of the costal margin of the distinct anterior wing. It was recorded sporadically only on boats regional, freight or passenger , where it finds an environment conducive to reproduction, shelter and food. It lives in dark, hot and humid environments, and accepts any type of food. He has nocturnal habits.

Pycnoscelus surinamensis

It is also known as a garden cockroach or grass cockroach. The adult ranges from 19 to 33 mm in length, without the antennae. Its color is brown. Reproduces by parthenogenesis, without the need for fertilization.

Males of this species are rare. It is found in external areas, where it lives and reproduces in gardens, areas of cultivation or accumulation of decomposing organic matter. It is considered a pest of circumtropical distribution.

They are occasional invaders of the residences, mainly in times of rain, when they run away from the excess water on the outside. They do not succeed in the internal environment of the houses.

It has low flight capacity and is transported by man, being a species restricted to the vicinity of human habitation. They are present in various types of plants, where they bury themselves in the shaded soil or debris accumulated in the leaf sheath, such as the coconut tree.

Its ability to adapt in different areas is facilitated by the displacement of plant seedlings by humans, which can cause serious damage, but is not likely to invade natural environments, unchanged.

Blaberus parabolicus

It is also known as big cockroach, spotted cockroach or cockroach. The adult varies between 55 and 83 mm in length, without the antennae. Males and females have a yellowish brown color with a square black spot on the pronotum.

This species belongs to the group of “false ovoviviparous”, for internally storing the ootheca in a “bag” where the eggs remain until the nymphs hatch.

It is a wild , Amazonian species that is adapting to the proximity of human habitations. It can be found outside and occasionally inside homes. It invades houses in rainy seasons to escape excess water.

Cockroach bites?

Amazingly, the cockroach does bite! This living being has no teeth, but it has strong jaws that are used to scrape the surface or food. Therefore, it feeds on feces, soap, leather and when found on the surface of our glass, they can “bite”. The cockroach has a preference for our hands, feet and mouth, in an attempt to find some food remaining to satisfy itself.

Cockroach fear

The great adaptability of cockroaches to the urban environment made it more frequent to manifest in environments where men live, especially due to the proximity of this insect’s habitat (sanitary pits, sewers and dumps).

In addition to appearance, habits cause real fear in people. So much so that there is a name to indicate the dread of cockroaches: catsaridafobia .

Do cockroaches cause disease?

If the cockroach passes over objects that go to the man’s mouth, it can transmit diseases. Photo: depositphotos)

The domestic cockroach is responsible for the transmission of various diseases, through the legs, since they transit through places where there is the presence of feces . For this reason, it is considered a threat to the health of human beings. It can transmit diseases related to various bacteria, fungi, worms, viruses and protozoa. Among the main ones, we can mention: hepatitis A, typhoid fever, tuberculosis, leprosy, diarrhea , polio and pneumonia.

Transmission occurs from the human’s oral contact with objects that the cockroach has passed the bacteria it carries in its paws. Example: food and household items. Contact with cockroach feces can also cause allergic reactions.

alternative medicine

On the other hand, according to some scholars, the cockroach has antibodies much more efficient than those found in the immune system of the human species. It is no wonder that these beings have lived on the planet for millions of years.

For this reason, there are several reports in folk medicine of cockroach species that can be used to fight certain types of diseases. Among them, alcoholism, asthma, bronchitis, intestinal colic, headaches and ear, boils, flu, among others, stand out.

The medicinal use is quite old. In the first century d. C., it was believed that the fat of a certain ” Blatta “, when ground with rose oil, treated earaches.

In traditional medicine in the Amazon, P. americana powder dissolved in wine, brandy or water is used in cases of urine retention, renal colic and asthma attacks. There is still a culture in Indonesia where cockroaches are roasted and eaten for asthma treatment. In Australia, the Yolnu people treat small cuts by placing a portion of crushed cockroaches in the wounds.

Zambian healers employ six species of cockroach, including P. americana and B. germanica , to treat boils and other skin problems. Periplaneta orientalis pills have already been taken for whooping cough, Bright’s disease, ulcers and warts.

However, there is still no scientific evidence regarding its effectiveness in men’s health.

How to avoid cockroaches at home?

The species of cockroaches that live close to the human being’s environment proliferate abundantly because we provide ideal conditions for their development. To minimize this situation, the best method of combat is cleaning inside and outside homes or commercial establishments, avoiding the accumulation of garbage and food scraps.

You should also avoid humid, dark and unventilated environments with many cracks, where cockroaches can hide. Domestic cockroaches, for example, are very sensitive to dryness and have nighttime activity, fleeing the light. In addition, cockroaches feed on fungi, which thrive primarily in this type of environment. Insecticide application is only advisable when there is a high level of infestation.

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