The German cockroach justifiably does not have a good reputation. Wherever it occurs, unsanitary conditions prevail. However, the appearance of pests does not necessarily have to be linked to poor hygiene. The insects need very specific conditions to survive.
Fighting German Cockroaches
Individual measures are usually unsuccessful if cockroaches have already spread throughout the apartment. The methods must be carried out continuously over a long period of time until the plague is defeated. However, chemical control methods should be left to professionals so that they do not unnecessarily harm your he alth. You should not crush the insects as you could carry the egg packets on the soles of your shoes.
| Effect | free available | |
|---|---|---|
| Antischabengel | feeding bait | yes |
| hormone-based remedies | impair growth and reproductive ability | no |
| Sprays and gases | Contactpoison | yes |
Detecting an infestation
You can catch and identify the insects with special traps. This is important so that you can take the right measures and not destroy harmless species. There are special sticky traps that have been provided with an attractant. The cockroaches are attracted to it and stick to the surface. This method is not suitable for combating and is only used for control purposes. If you discover an infestation in time, the chance of it being contained quickly is high.
First signs:
- Fecal crumbs that look like fine coffee powder
- Remnants of skin on the ground
- bad smells in the kitchen or pantry
Fecal crumbs are a sure sign of a pest infestation
Preparations
Before you take control measures, you should carefully clean the affected hiding places. Vacuum crumbs of feces, remains of molt and egg packets from the niches and dispose of the vacuum cleaner bag as a precaution. If the material allows it, you should clean the gaps with water that is at least 60 degrees hot. This destroys any remaining egg packets as they cannot tolerate the heat. Make sure that all food sources are eliminated. This is the only way control measures can be successful.
What you should do:
- Freezing food
- clean all surfaces and gaps
- Check appliances and furniture inside
Poison bait
An effective method of combating pests is to set up feeding poisons in the form of bait cans. When used correctly, this method poses little risk to people and the environment and ensures effective pest containment. In the past, food poisons such as fluorosodium silica or borax were used, which were mixed with baiting substances such as sugar. Today, contact poisons based on Gammexan or DDT are used. These substances must not be released into the environment as they are toxic to many organisms.
It has turned out that many baits available on the market are completely ineffective. The cockroaches would rather starve than eat the poison.
Diatomaceous earth
As an additional measure, you can spread diatomaceous earth in front of the hiding places. The powder consists of fossilized remains of diatoms and acts as a contact poison. If you dust hiking trails and hiding places with the powder, the pests will brush it off as they migrate. It sticks to the body and causes the insects to dry out.
Boric acid
This acid is used against cockroaches because of its insecticidal properties. There are frequent indications that a mixture of boric acid, margarine and sugar can be used as a home remedy. However, you should stay away from this because boric acid can also have an impact on your he alth. The substance is considered to be toxic to reproduction and can cause malformations in the embryo.
Pyrethrum
This substance is obtained from the flowers of various Tanacetum species and was already known by the ancient Romans as an effective insecticide. They called it “Persian insect powder” for a reason. Pyrethrum is used as a contact poison. It affects the nervous system of insects and causes the sodium channels to be blocked. The pests die as a result. However, pyrethrum does not have a selective effect, but also endangers beneficial insects and has a toxic effect on fish.
Prevention
Dirty dishes and leftover food magically attract cockroaches
If you discover cockroaches in your home, they are often imported pests. The insects rarely travel between a neighboring restaurant and residential buildings. By taking a few precautionary measures you can prevent the spread of pests.
Tip
Search your luggage thoroughly to quickly spot stowaways from warm holiday destinations. In southern countries, cockroaches are not uncommon.
Cleanliness
Since the development of cockroaches depends heavily on the food supply and humidity conditions, you should pay attention to increased cleanliness. Thoroughly clean hard-to-reach crevices and ensure good ventilation so that water does not collect in crevices and niches. Frequent ventilation regulates the humidity in the room air.
- wash dirty dishes immediately
- Remove organic waste from the apartment daily
- Wipe up food residue immediately
- Clean bathroom thoroughly
- Clean pet food bowls daily
Make living spaces unattractive
Since the German cockroach feels particularly comfortable in cracks, you should close them well. If the pests cannot find any spaces, they cannot use suitable egg-laying sites. Gaps under doors or between windows should also be sealed so that animals cannot get into the apartment.
- Store supplies closed in glass, ceramic or plastic containers
- Avoid cardboard or paper bags
- Avoid waterlogging in flower pots
Tip
Do not take home used packaging such as banana boxes from the supermarket. Egg packets could be hiding here.
Profile
The Swedish botanist and naturalist Carl von Linné first described this species and gave it the scientific name Blattella germanica. However, the species name has nothing to do with its natural distribution area. The German cockroach is known by many names and is also referred to as the house cockroach or Swabian beetle. It is a cockroach and has been given the nickname cockroach. The terms German cockroach and Croton bug are common in English.
This is what cockroaches are called in different parts of Germany:
- Southern Germany: “Prussia”
- Northern Germany: “Swabia”
- West Germany: “French”
- East Germany: “Russians”
Identifying insects
The cockroaches reach a body length of between 13 and 16 millimeters. They are light to dark brown in color and have two black longitudinal stripes on the pronotum. Males and females can be identified by their appearance. The latter are darker in color than their male counterparts. They also have a wider abdomen that is rounded at the end.
Special features
The German cockroach has wings, but cannot use them to fly. Only light males can sometimes be observed gliding. The young animals have not yet developed any wings. Instead, the cockroach is one of the good runners. They can cover a distance of up to 29 centimeters per second. This feature makes it more difficult to catch the insects.
- Insects stay in cold areas to feed
- lower temperature limit at four degrees Celsius
- can withstand a maximum temperature of 42 degrees Celsius
Confusion
The species can easily be confused with similar-looking cockroaches, which are not always considered pests. The species that are classified as cockroaches are of concern. The amber cockroach is a forest cockroach and cannot survive in buildings. The most striking distinguishing feature between this forest cockroach and the German cockroach is the pronotum. The amber cockroach has a monochrome pronotum without longitudinal stripes.
Cockroaches in comparison:
- German cockroach: light to dark brown in color, flightless
- Oriental cockroach: dark colored, flightless
- American cockroach: reddish-brown in color, able to fly
Lifestyle and development
This cockroach is nocturnal and spends 75 percent of a day in inaccessible hiding places. They only come out of their niches at night to feed or mate. If one insect walks around during the day, it indicates a large insect population in the hiding places.
Excursus
This is how the amber cockroach lives
These forest cockroaches naturally live in low bushes and gardens. They are often found under flower pots or in compost in summer as they feed on decomposing plant material. Unlike the German cockroach, this species prefers dry summer months with warm temperatures. The diurnal animals only occasionally get lost in apartments.
Social behavior
The cockroaches hide during the day in crevices that are about five millimeters high. Here they are optimally protected from enemies. They show unusual behavior because they form aggregations of several animals. These communities form when animals secrete pheromones through their feces. The substances have a regulating function and dissolve aggregates if necessary.
Development
The German cockroach produces egg containers called oothecae, which are light to medium brown in color. They act as a kind of cocoon and protect the growing organisms from external environmental influences. Adult cockroaches often live in hiding together with larvae. Since the conditions in buildings hardly fluctuate, several generations can emerge in one year.
Mating
The cockroaches mate just a few days after the last molt. Females ready to mate secrete scents into their intestines via glands, which are excreted in their excrement. In low concentrations, these have an attractive effect on males. If they are released in high doses, the mating game is triggered.
Egg Packages
The first ootheca is produced after about 14 days. Over the course of a lifetime, a female can develop between four and eight egg packets, each containing between eight and 50 eggs. During embryonic development, the female carries the egg containers on her body so that she can provide her offspring with moisture and nutrients. During this time their activity is very limited.
Egg laying
When embryonic development is complete and the larvae are about to hatch, the female seeks out a water source. By drinking, she increases the pressure of the body fluid, causing the ootheca to be rejected. The hatched larvae cannot move far and are dependent on the moisture conditions in the hiding place. They stay here for the next three days to shed their skin for the first time.
Stadiums
The larvae go through several stages until they become fully developed. Between the individual stages, the nymphs molt and increase in size. The first two stages have a very limited range of activity and do not move from their hiding places. They can be recognized by their dark brown to black breasts. The back has a light brown stripe that lightens in the later stages of development.
Occurrences
The pests occur in temperate latitudes, where they are strongly linked to humans. In nature, the species can only spread under warm and humid conditions. It prefers habitats with a temperature of 20 degrees Celsius. Little is known about their natural distribution area.
Typical outdoor habitats:
- Rotting dumps
- Cattle sheds on farms
- zoological gardens
Industry
The German cockroach is the most common species found in commercial kitchens, restaurants and hotels. The pests primarily attack rooms where food is processed or where the temperature and humidity are very high. This is why laundries and hospitals are often infested. In modern shopping centers there are countless hiding places and a diverse food supply, making such facilities particularly at risk.
House and apartment
Cockroaches are introduced into homes through food packaging, pallets and beverage crates. You can also find good hiding places in used electrical appliances. The pests then spread throughout the home, where they colonize suitable niches near sources of food and moisture. The insects require gaps with a minimum size of five millimeters. Larvae can crawl into cracks one millimeter high.
Cockroaches are hiding here:
- behind sinks and refrigerators
- in door frames and behind moldings
- in cavities behind tiles and in wall joints
- between picture frames and mirrors
German cockroaches often come into the house through packaging
Nutrition
The species is an omnivore. It has not specialized in a particular food supply, but relies on food that is easy to digest. Therefore, it cannot feed on wood, paper or leather alone. When there is a shortage of food, the insects eat injured conspecifics or egg capsules. The availability of food has a decisive influence on the activity of insects. If there is enough moisture, the cockroach can survive without food for up to three months.
This is what cockroaches eat:
- sugar and starchy foods
- rotting food
- animal foods
Digestion
The predominantly plant-based food is crushed using the biting, chewing mouthparts. They also have teeth in certain digestive organs, called chewing stomachs. There are also special bacteria here that can break down pulp.
Is the German cockroach dangerous?
The cockroach is considered a stored pest and plays a role that should not be neglected in the transmission of pathogens. An infestation by the species can cause he alth damage to humans and pets.
Harmful effects
Damage to food supplies is just as minimal as traces to textiles, leather and paper. However, the contamination of food caused by feces, secretion of salivary gland secretions and crop contents should not be underestimated. Contaminated food can be recognized by a foul smell. They are no longer suitable for human consumption and can also reduce the yield of meat and milk on farms.
Disease vectors
Various diseases such as tuberculosis, anthrax and salmonellosis can be transmitted via cockroach excretions. The German cockroach is an intermediate host for nematodes. Cockroaches have allergens that enter the air through feces and remains of their skin. These can cause asthma symptoms to a greater extent than other typical triggers.
Frequently asked questions
Is the German cockroach able to fly?
The species develops fully developed wings, but is unable to fly. German cockroaches mainly move by crawling. They are extremely agile and will quickly dart into their protective hiding places at night as soon as you turn on the light. Occasionally the animals can be observed gliding. However, only light and small males can glide, as females simply fall to the ground due to their weight.
Does the German cockroach have feelers?
The antennae of the German cockroach are particularly noticeable because they can be up to 1.5 centimeters long and consist of numerous individual limbs. As nocturnal animals, the pests depend on this because these antennae take on the function of sensory organs. They are used for orientation in the dark, while the eyes are more of a subordinate role.
How long does it take to develop from an egg to a cockroach?
In order for cockroaches to develop from the egg packets, the temperature and humidity must be right. Especially in the first larval stages, the creatures are unable to move. A nearby water source and warm temperatures favor their development. Under optimal conditions, the organisms go through all larval stages within 40 days. However, development normally takes two to three and rarely seven months.
Guidelines:
- At 30 degrees Celsius, development takes two months
- At 21 degrees Celsius the insects need half a year to fully develop
How old does the German cockroach get?
The lifespan of pests depends on the food supply and environmental conditions. The cockroaches feel particularly comfortable at warm temperatures of 20 degrees Celsius and above and high humidity. If they find enough food, their average life expectancy is between 100 and 200 days.
Does the German cockroach need food?
The cockroaches depend on the food leftovers that people leave behind. However, the insects can survive without food for a certain period of time. Adults and older larval stages can starve for up to 40 days if they have sufficient water sources. Without moisture, the animals cannot survive for long. They need moist and warm places near water sources.
What to do against cockroaches in the garden?
It may well happen that you find clusters of cockroaches in the garden. Suitable habitats include dense bushes such as ivy. The insects also occur in compost. However, you don't have to worry because the free-living species are not stored product pests. Often it is the amber cockroach, which is very similar to the German cockroach. Take a closer look at the pronotum. Only if it has two conspicuous black stripes is it a German cockroach.
