PCO Series: World of Cockroaches


Blatella Germanica with Ootheca ©Shutterstock/WStudio

Unhygienic, disgusting and smelly – these are probably the first thoughts that come to mind when you hear the name of this insect. We have summarised the negative and positive characteristics of cockroaches in this article and explain what to do in the event of an infestation or how it can be treated, as they can unfortunately cause considerable damage if not acted upon quickly enough, or even preventively.

Benefits and advantages

Of the approximately 4,500 different species of cockroaches, only a small percentage of these are known to be pests and live among us humans. The many other species in the wild are beneficial, not only as a food source for other creatures.

Cockroaches living in the wild are also important for plants. They contribute to plant reproduction by crawling through flowers in search of food and thus also transporting pollen. And they also eat what other creatures leave behind and  can be seen as natural waste recyclers.

We humans can also make use of them. These insects live in places that would cause diseases in other organisms. Therefore, researchers are now looking to develop a “cockroach” antibiotic for human use. That could then also fight bacterial infections (e.g. MRSA), which are resistant to conventional antibiotics.

The legs of cockroaches are of interest to scientists as well, as they are highly efficient and can be very useful for the development of prostheses, for example.1

Dangers and economic damage

Cockroaches feel at home in many places around the world, especially where the climate is warm and humid. These areas include the US state of Mississippi. The climate there seems perfect for these insects because cockroaches are among the most expensive pests to control there. The citizens of the state spend a lot of money every year to ensure that their house is cockroach-free. A one-time control usually does not solve the problem, as they keep coming back. Therefore, many homeowners contract with professional exterminators for regular control.

Not only in Mississippi but everywhere where there is such an optimal climate for these insects, the number of cockroaches correlates with people suffering from severe allergies and asthma, which in turn leads to an increase in health care costs.2

Characteristics and properties

As already mentioned, there are over 4,500 species of cockroaches. They can adapt very well to a wide range of conditions but still need enough food, water, warmth and suitable hiding places to survive and reproduce.3

If you search for harmful cockroach species in a search engine, you will very quickly find the names of the following:

Blatella germanica – German cockroach

This species grows to a size of 10 to 15 mm and is yellow-brown. A unique characteristic is the two dark longitudinal stripes on their neck shield. Despite well-developed wings, Blatella germanica cannot fly, only glide.4

Periplaneta americana – American cockroach

This roach is one of the largest cockroach species, as they grow up to 53 mm and are also easily recognisable by their reddish-brown colour. The wings of the males are slightly longer than their body, in the females they just cover the abdomen. Periplaneta americana also have strikingly long antennae, which can become even longer than their body. They move very quickly and are also capable of flight.5

Periplaneta Americana ©BioCycle (HK) Ltd

Blatta orientalis – Oriental cockroach

The males of this species grow up to 25 mm and have wings covering 2/3 of their body. The females are a little larger, up to 32 mm, but have receding forewings and their hind wings are not present at all. Blatta orientalis cannot fly.6

After fertilisation, the females form a so-called ootheca on their abdomen, an egg capsule in which their eggs lie in two rows. This purse-shaped “egg pocket” differs in size, colour and number of eggs growing inside, depending on the cockroach species. The ootheca of the German cockroach contains about 30 to 40 eggs, while the egg capsule of the American and Oriental cockroaches has only about 16 eggs.

Blatella germanica carry the egg case on their abdomen all the time until shortly before the nymphs hatch. Other cockroach species do not carry the ootheca with them but hide it near food sources. The nymphs undergo a series of moults until adulthood, varying from 6 to 13 times depending on the species.

The females of Periplaneta americana have the longest lifespan of 440 days on average, while the males only live to about 200 days. German cockroaches also have a life expectancy of up to 200 days. The females of Blatta orientalis live up to 181, their male partners only up to 160 days.7

Control and combat

Before an infestation can be controlled, it must first be recognised, identified, and the biology and habits of the species researched because each cockroach species needs a different treatment method. As the nymphs of all species are often very similar, they are difficult to distinguish, but adult cockroaches are usually easy to identify. With the help of glue or bait traps, they can be caught for an initial inspection to be able to determine the species and also provide an indication on the extent of the infestation. Only after these steps, a plan for removal can be drawn up by professional pest controllers. Most professionals agree that cockroaches can only be controlled with the help of several tools and strategies that work well together and take into account various factors, such as the extent, the available control agents and the cost-effectiveness.8 Baits and traps often play an essential role in control, but vacuuming up and removal of flushed cockroaches is also a very helpful way to quickly decimate a population.

Infested area of Blatella Germanica ©Shutterstock/IrinaK

Jesmond products and efficacy + application/dilution

To control an acute infestation but also as a preventive measure, we recommend our products Bombex® Pebbys CS, Bombex® Farumy and Bombex® MF. These have been tested for their cockroach effectiveness and are already being used successfully in various countries.

They offer numerous advantages thanks to the patented micro-encapsulation technology. The BOMBEX® products have an immediate and long-lasting effect (up to 12 weeks of protection), despite the more ecological water-based formulation, due to the tailor-made release rate of the active ingredients from the microscopic membrane capsules. In addition, they are safe to use, do not irritate the skin or the respiratory tract and do not have any unpleasant odours.

The products can be sprayed as well as fogged.

Spray application

Bombex® Farumy:          50 mL in 5 L water for 100 m²

Bombex® Pebbys:          25 mL in 5 L water for 100 m²

Bombex® MF:                  50 mL in 5 L water for 100 m²

These mixes can be used to treat all infested areas, with special attention to crevices and hiding places behind kitchen utensils and cabinets, drains, and warm and damp places where cockroaches like to stay and hide.

When using BOMBEX® products, the following points should be observed:

  • Follow the instructions on the label for the correct dilution.
  • Shake the container well before opening it.
  • Ensure that the container and sprayer have been adequately cleaned.
  • Properly mix and agitate the spray solution.
  • Shake sprayer occasionally while walking and use container stirring if available.
  • Use up all the material on the same day. Do not store the diluted mixture.
  • Ensure a medium to coarse spray with enough pressure to penetrate cracks and crevices.
  • Wet the surfaces well (50 mL/m²).
  • Dilute Bombex® product in water. Do not add other products or additives (whether spraying or fogging).
  • Consider principles of IPM (Integrated Pest Management).
  • If treatment is carried out after disinfection, the relevant surfaces must be dry before treatment with Bombex® to ensure the best efficacy.


Cockroaches living in nature have their purpose and role in our ecosystem. However, in indoor areas – particularly where food is stored or processed – they pose a serious danger and can transmit harmful diseases. Therefore, a professional pest control company should be contacted immediately after an infestation is discovered to ensure and maintain food safety.