Prussians (cockroaches) – what they are and how to control them

German cockroaches belong to the species of the common cockroach. Although they are commonly referred to as cockroaches, they differ significantly in appearance and origin.

The German cockroach originates from southern Asia and was brought to Europe in the 18th century, while the Oriental cockroach comes from the temperate zone of the northern hemisphere from the Caspian Sea to the Black Sea (Crimea), where it inhabits leaf litter and plant debris. Both species are synanthropic, which means that they feel comfortable in human environments and can be found in our houses, flats, garages and basements.

Cockroaches and pill bugs – differences in appearance

Cockroaches and pill bugs belong to the same taxonomic order, the order Blattodea, but to completely different families. Pill bugs are considered to be domesticated, while the common cockroach belongs to the family of cockroaches. Cockroaches are much bigger than woodlice, reaching a length of 17 to 29 mm. They also have a different colouring, being darker, brownish-black, and more heavily built. Woodlice are much smaller, with a body length of 10 to 14 mm and a lighter colour, described as amber or dirty yellow with a reddish tinge. They have a hard shell. On the head of the woodlouse, the pronotum, there are two darker brown stripes.

Woodlice move very quickly and have very agile antennae. They can climb both rough and smooth surfaces and, although they have wings, they cannot fly and only use them as a parachute when falling. They have small spines on their legs that help them climb any surface.

Where do cockroaches come from in the house?

Cockroaches reproduce quickly, they have a three-month reproductive cycle, during which time they are able to produce about 50 offspring. Cockroaches feed on anything organic, be it hair fragments, dead skin or food scraps. To prevent cockroaches from multiplying and infesting your home, you should frequently wipe down kitchen counters and remove food residue, thoroughly clean the bathroom of hair and dust, and unblock and clean drains (e.g. with hot water and vinegar), because although pillbugs cannot swim and will not enter pipes to other places, they can nest near drain outlets, e.g. in a sink where food leftovers can easily be left, you need to make sure that the rubbish is taken out regularly, seal all nooks and crannies by windows, cracks in walls, and also store food in tightly closed containers, do not leave food or dirty dishes overnight, as cockroaches feed after dark, when they come out of their hiding places. It is also worth checking the ventilation grilles and applying the poison there. If there are cockroaches in the neighbours’ apartment block, there is a high probability that they will spread to the neighbouring apartments. Cockroaches can also be transported in holiday luggage or with shopping, hidden in the nooks and crannies of packaging. Although it may seem difficult to protect yourself from them, all the above-mentioned activities minimise the risk of cockroaches appearing.

The danger of cockroaches in the apartment

The presence of cockroaches in the house can be dangerous to health. Although cockroaches do not bite, their rapid reproduction can lead to an infestation, which can simply annoy the household members. Nobody wants the presence of dozens of insects in their home. Cockroaches also contaminate household food supplies by leaving excrement and their faeces. But that’s not all: the droppings that woodlice leave behind can cause allergic skin and food reactions, and the risk of food poisoning is also increased, all because the insects carry mould spores and salmonella bacteria on their bodies. Studies have also shown that different species of cockroaches can spread other bacterial diseases such as tuberculosis, dysentery, typhoid, cholera, as well as viral diseases such as polio or hepatitis B, and even nematode larvae.

Combating silverfish

First, it is important to observe where the silverfish come from, where their nests might be and how they enter your flat. It is advisable to install insect screens on windows and ventilation shafts.

A mechanical method to fight bedbugs is to set traps by a pest control company. One of the frequently used and effective methods of fighting bedbugs is the gel method. Gel-like substances are spread on surfaces, thus luring insects to consume them. The poisoned insects go to their nest, where they die and are eaten by other individuals, who are also poisoned in this way. This method is recommended for homes, kindergartens, schools or health centres and wherever the use of general chemicals is not recommended.

Another effective method is ULV fogging. This involves dispersing the poison using a fogging device, which breaks the preparation down into small particles so that hard-to-reach places are also covered with the poison. These preparations leave microgranules in the environment that attach to the insect. The cockroach or cockroach-covered poison spreads the poison to other individuals, which then die.

Fighting cockroaches: home remedies

Home remedies for fighting unwanted insects are effective if there are not already a lot of them in the house. Below are methods that can help in this fight.

• Crushed bay leaves – scatter them where you don’t want the silverfish to get to,
• a mixture of sugar and baking powder,
• boric acid mixed with sugar – available in pharmacies, has an insecticidal effect, but is also dangerous for humans and pets,
• Sulphur ointment: spread it on leftover fruit or bread. When insects eat it, they are poisoned by the sulphur.
• Pour beer into a small bowl. The smell will attract insects, and the insects will be unable to escape the trap because they are intoxicated.

Recognising the presence of German cockroaches

At first, it is not easy to notice them because they come out of their hiding places at night. The German cockroach leaves behind it a trail of excrement that resembles ground coffee, which makes a line on the surface it has travelled. These insects moult several times in their lifetime, leaving behind their cast-off skin. Another alarming sign is the traces of feeding on our food, left on the kitchen counter, for example. Sometimes, dead individuals or eggs laid in the nest can be found in the nooks and crannies. Cockroaches mark their surroundings with their pheromones, which humans perceive as a pungent and sweet smell; in larger quantities, the smell can even be described as musty.