With this article and related ones we try to understand how to solve and prevent the problem due to the presence of cockroaches and cockroaches.
Recognizing a cockroach
There are 4600 species of cockroaches (also commonly called cockroaches) of which about 20 or so in the world are harmful for their interaction with man and his activities.
Cockroach orientalis or black
With its characteristic black colour, it lives in cool and humid environments such as basements, bathrooms and mainly in the sewers and inside the walls near the water pipes.
Adults can live up to 180 days, and females can produce up to 150 eggs during their lifetime. Eggs mature within 40-50 days, so infestations can be very persistent over time.
They climb little and do not fly, even if equipped with wings. They run very fast. They feed on organic matter of various types so that in environments with poor hygienic conditions its development can be considerable (e.g. sewers).
Germanic cockroach or stoker
With its characteristic light brown-red colour, the German cockroach is easily recognizable by the presence of two dark lines parallel, and vertical to the body, just behind the head.
The wings are well visible in the adults, but, like the orientalis cockroach, this cockroach does not fly.
It lives in warm humid environments and is used to infest kitchens and bathrooms, where it finds suitable climatic conditions and the organic material necessary for its survival.
Leftovers of food, hair, toothpaste, soap, paper, etc.. An adult can live for up to 100 days and each female can produce up to 350 eggs during her lifetime. After infesting an environment, she can move to neighbouring ones using the networks of hydraulic or electrical systems that run in the cavities.
American cockroach (Periplaneta americana)
Very large cockroach with well visible wings, especially in the males, dark brown-red-brown. It also prefers to live in humid environments and, in urban environments, proliferates mainly in sewers.
The adults can sometimes exceed the year of life and each female can produce up to 1400 eggs during her life. They have little ability to climb but are able to make small flights, they run fast.
They feed on organic matter of various types so that in poor hygienic conditions its development can be considerable, also due to the high prolificness of the adults.
Furniture cockroach or longipalpa supella
Length adult 9-14 mm., ooteca 4-5 mm. The adults, with a light brown colour, are recognizable by the presence of two light and horizontal bands on the body, behind the head.
The wings are well visible in the adults. They live in warm-dry interiors such as homes, offices, factories, industrial buildings.
The life of an adult lasts from 100 to 300 days about, and in this period the females can produce up to 350 eggs. This cockroach is omnivorous and is able to feed on many varieties of food and materials.
It survives well to the low humidity and therefore it is possible to find it also inside packaging, old furniture or household appliances, materials that also represent a vehicle of diffusion for this cockroach.
Egyptian cockroach or Polyphaga aegyptiaca
With the exception of the Egyptian Cockroach, reported only in some areas of southern Italy and considered a secondary pest, the other four species are widespread throughout Italy and are the main responsible for infestations.
It is very important to be able to distinguish between the species of cockroach in order to be able to take the appropriate preventive and pest control actions for their elimination.
It is important not to confuse these insects with other species that may be similar to cockroaches in morphology, size and colour.
Cockroaches, or cockroaches, have a squashed body. The antennae are filiform and very long, the legs are thin but robust, suitable for the slippery function and equipped with small hooks to allow these insects to climb even on apparently smooth surfaces.
The cockroaches may be winged, without wings or with little developed wings. Sometimes these differences are also found between males and females of the same species and therefore in the same environment it is possible to observe cockroaches able to make small flights and others unable to fly.
Signs of presence of cockroaches
Man himself, through the movement of goods, especially ships, has encouraged the spread of these insects in all parts of the world. Today, cockroaches live practically everywhere.
The cockroaches are, furthermore, very prolific insects, so the first signs of infestation should never be underestimated.
The first signs of the presence of cockroaches in a house that often go unnoticed are their eggs or rather the “ooteche”.
The cockroaches, in fact, do not lay their eggs individually, but several eggs contained inside a further casing that has the shape of a very small reddish-brown case.
This casing is called ooteca and the females of the cockroaches spread their ooteche in the environment, tending to be in dark or hidden places.
Some species transport the ooteca until they release it when the eggs are about to hatch (Blattella germanica), however even ootecas from which cockroaches have not already hatched can be found in the environment and are not distinguishable from those already hatched.
The morphology of the ootecas changes according to the species of cockroach present, so from the ootecas in some cases it is possible to understand what kind of cockroach we are dealing with even without having ever seen its adult forms.
The Germanic cockroach, moreover, in highly infested places releases an acrid and fruity smell in the environment that is sometimes perceptible to the sense of smell.
However, the first signs of cockroach presence can go unnoticed by untrained eyes, so in most cases sightings of live or dead cockroaches are the first sign of the presence of these insects.
Sightings are more frequent during the night or in dark ravines of the house because cockroaches are lucifugal, i.e. they avoid light and prefer places in the shade.
There are various species of cockroaches, which differ in ethological characteristics and habitat, and it is important to recognize the type of cockroach that you are dealing with to adopt the right methods of pest control.
Where cockroaches hide
The secret of cockroaches’ long survival for more than 200 million years lies in their ability to find suitable hiding places in any environment.
The environments where cockroaches most willingly hide are the warm and humid ones like kitchens and bathrooms, or cool and dark ones like closets, cellars, attics, garages, storerooms, under furniture where kitchen and bathroom drains are located.
In the majority of cases the Germanic Blatta infests kitchens and bathrooms and nests near or inside the motors of the appliances that produce heat.
Refrigerator, oven, dishwasher, microwave, washing machine etc… are all critical points to monitor in case of infestation.
Furniture may also be invaded and all areas of your premises may be affected by the presence of these insects in case of widespread infestation. Drawers and cupboards in the kitchen and drawer runners should always be checked.
They can also infest bedrooms, especially electrical systems and in some cases even air conditioners, heating systems and radiators.
It is also necessary to pay close attention to cracks and fissures in walls or broken and partially unglued tiles, as well as behind wallpaper, a frequent shelter for this weed.
In these environments it may be necessary to move appliances and furniture in order to understand where the cockroaches are hiding.
Oriental cockroaches and American cockroaches, on the other hand, usually live inside the sewer system and infest the dark, cool rooms at street level. Garages, cellars, etc…
This does not exclude their ascent, although less frequent, to the upper floors of buildings through plumbing and sewerage pipes.
From there, they can quickly infest all the rooms through the small cable or plumbing connections that connect adjacent rooms.
In some cases, they can also reach the ventilation or air extraction ducts in bathrooms and false ceilings.
It must always be remembered that cockroaches use the external wall of the hydraulic pipes to climb up to high rooms, and for this reason, when carrying out renovation work, great care must be taken not to leave open holes in the masonry at the points where the pipes pass through.
How the cockroaches arrive
In our cities there are many environments where cockroaches can enter and multiply, but certainly most of them live in the sewer networks of our cities.
Cockroaches can also be transported from one place to another by goods, food, equipment and means either in the form of live insects or by spreading their eggs inside containers of objects or food.
Very frequently the Germanic Blattella spreads by moving its eggs inside contaminated goods and food containers.
The Germanic cockroach frequently infests kitchens because it is attracted by food sources and the heat emitted by household appliances and can also move from one room to another through the outer walls of pipes and cracks in the walls.
The proximity of the infested premises to a restaurant or an environment that handles cooked food is sometimes the cause of the infestation.
It is always a good idea to consult with the owners of the premises next to the infested one in order to understand the source of the infestation and take the right corrective action.
Almost always, on the other hand, the presence of the Eastern Cockroach or the American Cockroach is due to the ascent of these insects from the sewers or plumbing systems.
A particularly full and obstructed sewer can give rise to widespread infestations of this type of cockroach. For this reason, regular destruction of the sewer system is necessary.
During the renovation works it is also necessary to pay the right attention and take all possible precautions not to facilitate the passage of cockroaches from the sewer system to the internal rooms through the holes made in the walls.
Also for the infestations from Eastern cockroach and American cockroach it is necessary to pay the right attention to the rooms close to the infested one. Abandoned and humid rooms can be the source of the infestation and should be monitored.
Ultimately all environments can be subject to cockroach infestation and it is wrong to think that only rooms with poor hygiene are at risk, although poor hygiene and the presence of organic waste and water contribute to a greater reproduction and spread of these insects.