Cockroaches are one of the oldest known insects, since there are fossil remains that are more than 300 million years old and, in all this time, they haven't changed much.
Currently, many species of cockroaches are closely linked to human activity and its waste, so it is common to see them, especially in summer, when the heat on the surface causes them to emerge from their hiding places. It's no wonder you've been terrified when you come across this insect.
In this article on our site we will find out if all cockroaches really fly or why cockroaches fly towards you.
Cockroach taxonomy
The taxonomy is the branch of biology responsible for organizing the phylogenetic tree of life by taxa. Next, we will detail the taxonomy of cockroaches up to the Order taxon since, later, it branches into several families according to the species:
- Domain: Eukarya. For being multicellular organisms whose nuclei are true.
- Animalia Kingdom . For having locomotion capacity, feeding by ingestion, reproducing sexually, consuming oxygen in the breath and having embryonic development.
- Subkingdom: Eumetazoa. For presenting actual tissues such as epidermal or connective tissue. Development of the nervous system.
- Phylum: Arthropoda. Invertebrate animals with exoskeleton and articulated appendages (legs, antennae or jaws).
- Superclass: Hexapoda. Body divided into tagmata: head, thorax and abdomen.
- Class: Insect. Arthropods characterized by having a pair of antennae, 3 pairs of legs and two pairs of wings, which in some cases may be reduced or absent.
- Subclass: Pterygota. They present in the second and third tagma of the thorax the two pairs of wings, that is, they are winged insects.
- Underclass: Neoptera. Winged insects that when at rest keep their wings close to the body.
- Order: Blattodea. Cockroach-like insects among
- Families: Blaberidae, Blattellidae, Blattidae, Cryptocercidae, Polyphagidae and Nocticolidae.
Physical characteristics of cockroaches
The main characteristic of this group of animals is their strongly flattened body. Depending on the species, there are cockroaches smaller than one centimeter in arctic areas and larger than 7 centimeters in the most tropical areas of the planet.
Nearly all of them are dark in color, brown or black. The exoskeleton is smooth, rarely has setae or sensory hairs, although the hind legs do usually have protective spines. The thorax has a very developed and flattened proton (first segment of the thorax; dorsal) that covers the head. They have legs long and developed for the race.
They have an orthognathic and even hypognathic head, that is, the mouthparts are directed downwards and the head is placed perpendicular to the body. They have a pair of very long antennae. The eyes are compound, large and set laterally on the head. They also have paired and lateral ocelli (sensory organs). They have a chewing mouthparts with very robust jaws, their omnivorous diet is very varied.
Do cockroaches sting or bite?
Cockroaches don't bite because they don't have any organs for it, but do they bite? They have the ability and, in addition, their bite is very strong, since they feed on almost anything, including hair, paper or glue, although their favorite food is decomposing organic matter, rich in sugars and fats.
Although it is unusual, a hungry cockroach can bite a person or another animal. They usually do it in places where organic debris accumulates, such as feet, nails or eyelashes.
Cockroaches with wings and without wings
These insects belong to the subclass pterygota, which are characterized by being insects with wings, but not all cockroaches fly Most of the the Blatodeos have wings, but some, in the adult state, have them reduced or absent, usually the females. This is known as neoteny, that is, the presence of juvenile characters (absence of wings) in the adult state. Another well-known neoteny is the "baby" gaze of adult dogs.
Insects usually have two pairs of wings This is the case of cockroaches. The wings of the first pair, called tegmites, are leathery (hardened in appearance) and, at rest, the left covers the right. The second pair of wings is sheltered under the first pair when the animal is not flying. All wings are strongly innervated.
- Most common flying cockroach species in Spain: Blattella germanica (German or blond cockroach), Periplaneta americana (American or red cockroach) and Periplaneta australiasea (Australian cockroach).
- Most common flightless cockroach species in Spain: Blatta orientalis (black, oriental, common or Old World cockroach).
Even though they have wings, cockroaches' flight is more like a glide than an actual flight, so if we meet with a cockroach on the wall, he gets scared and sees no escape route on foot, he will try to fly. As they don't control the flight very well, the easiest thing is to leave the wall with a perpendicular trajectory, so the cockroach will appear to be flyingtowards us and, in many cases, it will end up colliding with our body in an unintended way.
Flight Mechanism
Each wing of the cockroach, during flight, performs a move in the shape of an "8" It goes down during the flapping and goes up during the downcast. This movement is responsible for the advance of the animal during the flight, the descending movements of the wing are what give the force.
If the animal is able to control the angle at which it moves its wing, it will have a lot of control over its flight, including flying backwards. Not the cockroach, which only flies forward.
On the other hand, it has been shown that the edge of the wing generates a very powerful propeller-shaped airflow producing upward thrust.
Unlike flying birds, insects do not have flight markers in their brains. Instead they have receptor or sensory organs in the thorax and wings. Balance during flight is achieved by other sensory receptors located in the head.
Diseases transmitted by cockroaches
Cockroaches can transmit or be natural reservoir of pathogens During the day they live in dark, humid and warm places, with a high degree contamination, such as sewers, septic tanks or sewers, and at night they come out and walk freely through cupboards, pantries, kitchens, etc.
Its legs, digestive tract and integument (skin) are covered by thousands of bacteria and other microorganisms (whether harmful to the he alth or not). The transmission of these pathogens occurs when the cockroach regurgitates food, by contact with its extremities or by droppings.
- Bacterial Diseases Transmissible by cockroaches: dysentery, gastroenteritis, typhoid fever, plague, gangrene, leprosy, Asiatic cholera, meningococcal meningitis, pneumonia, diphtheria, brucellosis, glanders, anthrax, tetanus and tuberculosis.
- Transmission of helminths (worms): Oxyspirura mansoni, which attacks the eyes of poultry, Moniliformis moniliformis and Moniliformis dubius.
- Transmission of protozoa: Balantidium coli, Entumoeba histolytica, Giardia intestinalis, Toxoplasma gondii and Trypanosoma cruzi.
- Transmission of fungi of intestinal flora: Mortierella spp., Aspergillus spp., Candida albicans and others.
