What are German Cockroaches?

German cockroaches are common insects that can infest homes, apartments and other structures. They belong to the order Blattodea and can be found almost anywhere throughout the year, regardless of the season, especially indoors. Blattella germanica L. is the most common species of cockroaches that can be found indoors. A single female can spawn thousands of offspring each year, which can turn a minor problem into a significant infestation.

Where can they be found?

German cockroaches can be found in various locations, such as homes, apartments, schools, restaurants, offices and anywhere where there are areas for food preparation or storage. They can contaminate food, utensils and paper products. They can also destroy fabrics. The cockroaches are mainly active at night. If they can be seen during the day, there may already be a significant infestation.

Monitoring and inspection are essential in managing a cockroach infestation.

Units with no history of cockroach infestation should be proactively inspected at least once or twice a year, and those with a history of infestation should be inspected once every 3 months.

Monitoring

Monitoring can be done by placing adhesive traps. These traps should be strategically placed in kitchens and bathrooms, attached to the wall, inside a cupboard, under the sink or between the fridge/freezer and cupboards. They contain an attractant to lure cockroaches and trap them on the adhesive surface.

They are mainly used for inspecting or monitoring the degree of infestation. They are therefore not used for control.

The traps can be placed before carrying out the treatments, to identify the access routes of cockroaches indoors. Additionally, traps can also be placed after the chemical treatments to check the results and monitor the treated space. Subsequently, depending on the number of pests trapped, repeating the chemical treatment may be taken into consideration.

If an infestation is found, it is recommended to vacuum properly all the places where cockroaches are found or may be hiding.

Controlling German Cockroaches

Carrying out extensive treatments throughout the entire apartment complex is the main recommendation. A localized approach may be ineffective because cockroaches can easily move through walls, pipes or common spaces. An infestation can quickly spread to apartments that have not been treated, which can lead to reinfestation.

Ready-to-use (RTU) gel insecticides /  with an attractant in their composition against German cockroaches

A unique characteristic of gel insecticides with an attractant in their composition for the control of German cockroaches is the “cascade effect”, which results in the elimination of the entire nest. The insecticide contains attractants that lure pests within a radius of several meters. The cockroaches consume the insecticide and become contaminated. Within 24 hours, beetles that have consumed the gel will die. The healthy beetles feed on the droppings and remains of other dead bugs, spreading the insecticide and amplifying the effect of the gel. Thus, a single infested beetle can result in the elimination of a nest, ensuring an effective and long-lasting control solution.

Recommendations

• It is advisable to leave the dead cockroaches in place or you can place them in a corner. This will ease the spread of the insecticide and increase the effectiveness of the treatment.
• The insecticidal gel is applied in “beads” at a distance of 1-2 m, in areas where the cockroaches can hide (drainpipes, under and behind appliances, on door frames, electric meters, dark corners, cracks in the wall or floor).
• The reapplication of the gel should be done regularly, every three months or when it has been consumed. The size of the beads should be about the size of a grain of rice. Additionally, it is advisable to eliminate any potential food sources for cockroaches before applying the insecticidal gel.

! It is not recommended to apply the gel in the form of bands and to apply other treatments (spraying, nebulization, powder) at the same time as the gel (it may lose its attractant properties).

The use of bait stations is recommended for gel insecticides. Bait stations protect the gel from external factors and prevent non-target creatures from coming into contact with the substances inside. They do not replace pest traps or block the beetles inside, but are strictly used to protect the insecticides applied.

Ready-to-use insecticide treatments

Being ready to use they are a convenient option for pest control, offering a quick and easy application.

Recommended Ready-to-use insecticides against German cockroaches

It is not necessary to prepare the solution, thus saving time and effort. They also reduce the risk of contact with potentially hazardous concentrated substances. They are ideal to be used by home users, are easy to apply and do not require any special equipment.

Insecticide concentrates against German cockroaches, coarse application / residual effect

For the elimination of adult cockroaches, it is recommended to use insecticide concentrates that have a specific knock-down effect. This effect refers to the ability of insecticides to rapidly incapacitate the target pests. The insecticides have an effect on the insect’s nervous system (by contact or ingestion), leading to paralysis or death.

Effect by ingestion: The cockroaches consume the insecticide by ingesting contaminated food or water. Once ingested, the product enters the digestive system and poisons the pest.

Insecticide concentrates for coarse/residual application with an effect through ingestion:

Effect through contact: Cockroaches come into contact with the insecticide when they pass through the treated surfaces. The insecticide penetrates the insects’ bodies through the cuticle (the hard exterior layer) and poisons them.

Insecticide concentrates for coarse/residual application with an effect through contact:

It is recommended to apply the insecticides using special sprayers. Sprayers are low-pressure applicators, which are used to apply insecticides with precise dosage.

Treatments with insecticides in powder form

Insecticides in powder form can be used in hard-to-reach areas where liquid insecticides cannot be applied (e.g. holes, electrical installations, cracks, etc.). The products are not dissolved in water. It is important to identify and treat areas with the greatest potential for cockroach nests. As soon as the infested area has been spotted, a band is applied and the pest will collect the lethal dose as it passes through the powder.

The application of treatments with insecticides in powder form is done after the application of treatments applied by spraying.

The spray will kill any exposed insects and create an insecticidal barrier on surfaces, while the powder insecticides will complete the subsequent treatment by controlling insects in hard-to-reach spaces (cracks, crevices and spaces behind furniture).

It is very important that the application of powder insecticides is carried out a few days after the application of spray insecticides, only when the surfaces are completely dry.

Insecticides in powder form can be used together with aerosol insecticides for optimum effect.

In hard-to-access areas, powders can be applied with special devices.

Diatomaceous Earth for Cockroach Control

Diatomaceous earth is highly effective against kitchen and sewer cockroaches, targeting all stages of their life cycle, including adults, eggs, and larvae, ensuring a comprehensive solution for infestation control.

The powder formulation can be applied by sprinkling a thin layer of diatomaceous earth in areas frequently visited by cockroaches, such as cracks, corners, behind appliances, and around drains. Allow it to act for 2-3 days, then vacuum or clean the treated area thoroughly. Diatomaceous earth works by dehydrating cockroaches and damaging their exoskeleton. It is important to apply the product in undisturbed areas where daily activities will not remove it. Always use biocide-authorized diatomaceous earth, which is safe for humans and pets.

The aerosol formulation is an efficient alternative for kitchen cockroach control, particularly in situations where applying powder or liquid solutions is not feasible. This allows for deeper penetration into cracks and crevices, making it highly effective for treating hidden infestations.

The ready-to-use liquid formulation is ideal for even application over large surfaces, ensuring efficient distribution and easy spraying. This method guarantees optimal results against kitchen and sewer cockroaches. It is recommended to apply it in cracks, corners, behind appliances, and around drains, where cockroaches tend to hide. After 2-3 days, vacuum or clean the area to remove dead insects and any excess product.

Aerosol/fumigant insecticides against German cockroaches

A more effective approach to controlling German cockroaches is a treatment that combines both spraying and aerosol or fumigant doses. The application of the aerosol or fumigant treatment is done after the solutions applied by spraying, when they will dry. The pests will come out of their hiding places or hard to reach spots because of the irritation caused by the fumes, coming in direct contact with the insecticide sprayed previously.

ULV fogging is an alternative to aerosol cans. This technique uses a ULV device that transforms the liquid insecticide into a fine mist that disperses evenly in the treated space.

Insecticide concentrates that can be applied by ULV fogging to achieve a flush-out effect – post coarse application/treatment with residual effect

Insecticide concentrates can be diluted and applied with a ULV device to achieve a flush-out effect. This method of application irritates the insects that are hiding in hard-to-reach spaces, thus increasing the effectiveness of the treatment.

The application of insecticides by fogging is recommended in the following fields:

• Companies: offices, warehouses, restaurants and other commercial locations;
• Hotels/guesthouses: allows the efficient management of rooms and common areas.

! The insecticides will be chosen taking into account the equipment used – if the insecticide is not suitable, the equipment might malfunction.

Safety equipment

Safety equipment has the role of protecting the person that is performing the disinsection treatments. To avoid inhalation of vapors created during spraying or direct contact with the applied substances, it is recommended to wear a complete protective suit. This includes hooded protective coveralls, gas masks with filters, chemical protection gloves, rubber boots, or waterproof footwear, as appropriate.

Recommended safety equipment:

Safety equipment has the role of protecting the person performing the treatments from dangerous substances. This category includes protective gloves, coveralls, masks, etc. The equipment is chosen based on the type of treatment, as well as the substances used or the pest that is being controlled.

• Hooded chemical-resistant suit

• Protective gloves

• Gas masks, glasses

Thorough vacuuming and sanitization

This process eliminates a significant part of the cockroach population, both adults, eggs and young stages of development. It is important to pay special attention to the areas where cockroaches may hide:

• Cracks and crevices in walls, floors and furniture;
• Spaces behind household appliances;
• Hard-to-reach corners and spaces;
• Under sinks and cupboards.

Vacuuming should be carried out with a HEPA vacuum cleaner (High Efficiency Particulate Air – a special filtering system that retains small particles such as fine dust, allergens, bacteria). It is recommended to use a disposable bag, which should be sealed and disposed of immediately after vacuuming.

Pay particular attention to the areas behind and under the stove, refrigerator, microwave and sink, where leftovers can accumulate. Keep food in sealed containers to eliminate food sources for cockroaches. Keep garbage bins clean and covered to prevent the cockroaches from getting in.

Cockroaches can cause a number of problems

Health risks

• their saliva and feces can trigger asthma attacks, especially in young children;
• they can be carriers of harmful bacteria, contaminating food and the surfaces they crawl on (this can lead to diseases such as food-borne infections, salmonella and dysentery).

Material damages

• they can gnaw and damage various materials, including fabrics, furniture and books;
• they release an unpleasant odor.

Common ways by which cockroaches can get into your home

• Cockroaches can hide in cardboard boxes, shopping bags or other types of packages;
• New or second-hand furniture can be infested;
• They can migrate into the house (through cracks, down pipes, vents or drains).

Signs of an infestation

Being nocturnal, their presence is more noticeable at night. Because of their size and the characteristics of the species, the presence of an infestation is obvious.