The German cockroach justifiably has a bad reputation. Where it occurs, unsanitary conditions prevail. However, the appearance of the pests does not necessarily have to be associated with poor hygiene. Insects need very specific conditions to survive.

As long as the cockroach can only be found in the garden, there is no need for action

Table of Contents

Show all
  1. the essentials in brief
  2. Fight
  3. Prevent
  4. Characteristics
  5. recognize insects
  6. lifestyle and development
  7. development
  8. Happen
  9. nutrition
  10. Dangerous?
  11. frequently asked Questions

    12. the essentials in brief

    • Cockroaches can be controlled with feeding baits, hormone-based agents and contact sprays
    • Poison bait is the most effective remedy for cockroaches
    • Affected cracks and corners can be rinsed out with 60°C hot water; that kills eggs and animals
    • To prevent an infestation, attention should be paid to cleanliness

    Combat German cockroaches

    Individual measures are usually not successful if cockroaches have already spread in 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 you do not unnecessarily impair your health. You should not step on the insects, as you could carry the egg packets on the soles of your shoes.

    effect freely available
    anti cockroach gel eating bait Yes
    hormone-based drugs impair growth and fertility no
    aerosols and gases contact poison Yes

    Recognize an infestation

    Special traps allow you to catch and identify the insects. 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. If you discover an infestation in time, the chance of rapid containment is high.

    First signs:

    • Poop crumbs that look like fine coffee powder
    • remains of molting on the floor
    • bad smells in the kitchen or pantry

    Fecal crumbs are a sure sign of a pest infestation

    preparations

    Before you carry out any measures to combat it, you should carefully clean the affected nooks and crannies. Vacuum crumbs of droppings, remains of molting 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 the remaining egg packets, as they cannot tolerate the heat. Make sure that all food bases are eliminated. Only in this way can countermeasures be successful.

    What you should do:

    • Freeze food
    • Clean all surfaces and spaces
    • Check equipment and furniture inside

    poison bait

    An effective method of combating the pests is to put up feeding poison in the form of bait cans. When used properly, this method poses little risk to people and the environment and ensures effective pest control. In the past, food toxins such as sodium fluoride or borax were used, to which baiting substances such as sugar were added. 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 been found that many commercially available baits 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 fossil remains of diatoms and acts as a contact poison. If you dust hiking trails and hiding places with the powder, the pests strip it off as they migrate. It sticks to the body and ensures that the insects dry out.

    boric acid

    This acid is used against cockroaches because of its insecticidal effect. There are frequent indications that a mixture of boric acid, margarine and sugar can be used as a home remedy. However, you should keep your distance from this, because boric acid can also affect your health. The substance is considered 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 to the ancient Romans as an effective insecticide. They didn't call it "Persian Insect Powder" for nothing. 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 act selectively, but also endangers beneficial insects and is toxic to fish.

    Prevent

    Dirty dishes and leftovers magically attract cockroaches

    If you discover cockroaches in your home, they are often imported pests. Insects seldom overcome distances between neighboring gastronomy and residential buildings. With a few precautionary measures, you can prevent the spread of pests.

    tips

    Also search luggage thoroughly in order to quickly discover stowaways from warm holiday countries. Cockroaches are not uncommon in southern countries.

    cleanliness

    Since the development of cockroaches depends heavily on the food supply and moisture conditions, you should pay attention to increased cleanliness. Thoroughly clean hard-to-reach crevices and ensure good ventilation to prevent water from accumulating in crevices and niches. Frequent forced airing regulates the humidity in the room air.

    • wash dirty dishes immediately
    • Remove organic waste from the apartment daily
    • Wipe up food residue immediately
    • Thoroughly clean the bathroom
    • Clean pet bowls daily

    Make living spaces unattractive

    Since the German cockroach feels particularly comfortable in cracks, you should close them well. If the pests do not find any spaces in between, they cannot claim suitable egg-laying sites. Gaps under doors or between windows should also be sealed so that the animals cannot get into the apartment.

    • Store supplies closed in glass, ceramic or plastic jars
    • Avoid cardboard or paper bags
    • Avoid waterlogging in flower pots

    tips

    Do not take used packaging, such as banana boxes, home from the supermarket. Egg packets could be hiding here.

    Characteristics

    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 range. The German cockroach is known by many names and is also referred to as the house cockroach or Swabian beetle. It belongs to the cockroaches and has been given the nickname cockroach. In English, the terms German cockroach and Croton bug are common.

    This is how the cockroaches are called in different parts of Germany:

    • Southern Germany: "Prussia"
    • Northern Germany: "Swabia"
    • West Germany: "French people"
    • East Germany: "Russians"

    recognize insects

    The cockroaches reach a body length 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.

    particularities

    The German cockroach has wings, but cannot use them to fly. Only light males can sometimes be seen gliding. The young have no wings yet. Instead, the cockroach is one of the good runners. They can cover a distance of up to 29 centimeters per second. This property makes it difficult to catch insects.

    • Insects stay in cold areas to feed
    • lower temperature limit at four degrees Celsius
    • endure a maximum temperature of 42 degrees Celsius

    confusion

    The species can easily be confused with similar-looking cockroaches, which are not always considered storage pests. The species that are counted among the cockroaches are questionable. The amber cockroach belongs to the forest cockroaches 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 single-colored pronotum with no vertical stripes.

    Cockroaches in comparison:

    • German cockroach: Light to dark brown in color, unable to fly
    • Oriental cockroach: dark colored, unable to fly
    • American cockroach: red-brown colored, 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 an insect roams around during the day, this indicates a large insect population in the hiding places.

    digression

    This is how the amber cockroach lives

    These wood cockroaches naturally live in low bushes and in gardens. They are often found under flower pots or in compost during the summer as they feed on decomposing plant matter. Unlike the German cockroach, this species prefers dry summer months with warm temperatures. The diurnal animals only occasionally get lost in apartments.

    social behavior

    During the day, the cockroaches hide in crevices that are about five millimeters high. Here you are optimally protected from enemies. They show a conspicuous behavior because they form aggregations of several animals. These communities form when the animals secrete pheromones in their feces. The substances have a regulating function and dissolve aggregates again if necessary.

    development

    The German cockroach produces egg receptacles 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 together with larvae in a hiding place. Since the conditions in buildings hardly fluctuate, several generations can arise in one year.

    pairing

    The cockroaches mate just a few days after the last moult. Females ready to mate secrete scents into the intestine via glands, which are excreted with the excrement. In low concentrations, these are attractive to males. If they are poured out in large doses, the mating game is triggered.

    egg packets

    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 cases on her body so that she can provide moisture and nutrients to her offspring. 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 so that the ootheca is expelled. The hatched larvae cannot travel far and are dependent on the moisture conditions in the lair. They stay here for the next three days to molt for the first time.

    stages

    The larvae go through several stages up to the fully developed cockroach. Between the individual stages, the nymphs molt and increase in size. The first two stages have a very restricted radius of activity and do not move from their hiding places. They can be recognized by their dark brown to black chest. The back is marked with a light brown stripe that lightens in the later stages of development.

    Happen

    The pests occur in the temperate latitudes, where they are closely 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 range.

    Typical outdoor habitats:

    • rotting dumps
    • cattle stalls on farms
    • zoological gardens

    Industry

    The German cockroach is the most common species found in commercial kitchens, restaurants and hotels. The pests primarily infest rooms in which food is processed or in which the temperature and humidity are very high. Therefore, laundries and hospitals are often infested. In modern shopping centers there are countless hiding places and a diverse range of food, so that such facilities are particularly at risk.

    house and apartment

    Cockroaches are brought into homes through food packaging, pallets and beverage crates. You will also find good hiding places in used electrical appliances. Subsequently, the pests spread throughout the apartment, where they colonize suitable niches near sources of food and moisture. The insects need gaps with a minimum size of five millimeters. Larvae can crawl into cracks a millimeter high.

    This is where cockroaches hide:

    • 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. She has not specialized in a specific food supply, but is dependent on easily digestible food. Therefore, she cannot feed on wood, paper, or leather alone. When food is scarce, the insects eat injured conspecifics or egg capsules. The availability of food has a decisive influence on the activity of the insects. If there is enough moisture, the cockroach can survive up to three months without food.

    This is what the cockroaches eat:

    • sugary and starchy foods
    • rotting food
    • animal foods

    digestion

    The predominantly vegetable food is crushed with the biting-chewing mouthparts. They also have teeth in certain digestive organs called gizzards. There are also special bacteria that can break down cellulose.

    Is the German cockroach dangerous?

    The cockroach is considered a storage pest and plays a not inconsiderable role in the transmission of pathogens. An infestation by the species can cause health problems in humans and pets.

    harmful effect

    Feeding damage to food supplies is just as minor as traces to textiles, leather and paper. On the other hand, contamination of the food caused by faeces, secretion of salivary gland secretion and crop contents should not be underestimated. Contaminated food can be recognized by a foul smell. They are no longer fit for human consumption and can also reduce the yield of meat and milk on farms.

    disease carriers

    Various diseases such as tuberculosis, anthrax and salmonellosis can be transmitted via the excretions of the cockroaches. The German cockroach is an intermediate host for nematodes. Cockroaches have allergens that get into the air via faeces and residues of skinning. These can cause asthma symptoms to a greater degree than other typical triggers.

    frequently asked Questions

    Can the German cockroach fly?

    Although the species develops fully developed wings, it is unable to fly. German cockroaches move mainly by crawling. They are extremely nimble and will dash to their protective hiding places as soon as you turn on the light at night. Occasionally the animals can be seen 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 are particularly noticeable in the German cockroach, because they can be up to 1.5 centimeters long and consist of numerous individual segments. As nocturnal animals, the pests are dependent 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 subordinate.

    How long does it take to develop from egg to 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. Normally, however, development takes two to three and rarely seven months.

    Guide values:

    • at 30 degrees Celsius development takes two months
    • at 21 degrees Celsius, the insects need half a year for their full development

    How old does the German cockroach get?

    The lifespan of the pests depends on the food supply and environmental conditions. The cockroaches feel particularly comfortable in warm temperatures above 20 degrees Celsius 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 are dependent on the food leftovers that people leave behind. However, the insects can survive without food for a certain amount of time. Imagines and older larval stages can starve for up to 40 days if they have sufficient water sources. The animals do not survive long without moisture. They need moist and warm places near water sources.

    What to do against cockroaches in the garden?

    It is quite possible that you will find clusters of cockroaches in the garden. Suitable habitats are dense bushes such as ivy. Insects can also be found on the compost. You don't have to worry, however, because the free-living species are not stored product pests. It is often the amber cockroach, which is very similar to the German cockroach. Take a closer look at the pronotum. It is only a German cockroach if it has two conspicuous black stripes.

Category:

Animals in the garden