The main problem with cockroaches as pests is that they are carriers of bacteria, viruses and fungi. In addition to being able to transmit Salmonella, the pathogen that causes food poisoning, they are also carriers of Streptococcus, Clostridium, and other substances that cause deadly diseases. These diseases may be caused by food contamination.
Contamination of food can occur through their excrement. Cross-contamination can also occur when bacterial organisms are deposited on food. These bacterial organisms can be picked up when removing food (garbage, sewage, etc.) or other raw food sources.
In addition, cockroaches have no specific dietary preferences, they consume a variety of foods and items. They eat almost anything! In addition to the food we eat, they also consume soap, glue, leather, and items such as animals, animal feces and dead plants. This significantly increases the possibility of cross contamination.
Due to the presence of allergens in saliva secretions and body parts, we may have allergic reactions to cockroaches. This can trigger adverse reactions, leading to rashes, watery eyes and sneezing.
These allergens can cause severe asthma and even life-threatening. Non-asthmatic patients will still develop cockroach asthma when they inhale allergen cockroaches.
It is very rare to be bitten by a cockroach, but some species can bite. As mentioned above, cockroaches eat almost anything, so including nails, soft skin parts and even a strand of hair!
The life cycle of a cockroach
egg
Female cockroaches do not lay eggs alone, they reproduce egg shells, also called oocysts. Ootheca contains many eggs, depending on the type of cockroach. (For example, the German cockroach ootheca can carry about 30-40 eggs, while the American cockroach can carry about 16-20 eggs)
Nymph
The newly hatched nymphs are wingless and white. Soon after birth, they will change from white to brown and their exoskeletons will harden. Before becoming an adult, the nymph must undergo several molting processes. After the final molting, the nymph (depending on the species) will form wings. The duration of the process from nymph to adult depends on the species. Some may only take a few weeks, while others may take up to a year. For example, the German cockroach needs about. After molting 6 to 7 times, it becomes an adult for 3 months, while the Oriental cockroach takes one to two years to become an adult after molting 7 to 10 times.
adult
The life span of an adult cockroach varies from species to species. Its average is about one year. However, factors such as temperature and other environmental conditions also determine the viability of cockroaches. Cockroaches are essentially nocturnal animals. They remove water and food at night. They can also reproduce very quickly, so when overcrowding occurs, some cockroaches are forced to clear them out during the day.
Signs of cockroach infestation
manure
Cockroach droppings are one of the clear signs of cockroach infestation. Depending on the size of the cockroach, cockroach feces can be the size of rice or coffee powder. The color of feces is usually black, ranging from black to dark brown.
The size of house mouse feces and cockroach feces may be similar, but they are visually different. House mouse feces have sharp points, while cockroach feces are cylindrical with ridges along the sides. The volume of feces can also be used as an indicator of the number of cockroaches you are dealing with.
odor
One of the signs of cockroach infection is through smell. The smell is usually described as musty and greasy. This smell is caused by the pheromone produced by cockroaches. Pheromone is a chemical signal. As a form of communication between cockroaches, it serves two purposes:
(I) Aggregate pheromone
Although cockroaches live in a group, unlike termite groups, which have an organized social structure, different members play different roles. Cockroaches do not have an organized social structure without them. They prefer group life. Therefore, when a cockroach finds a good place to live, it will indicate that the place has a pheromone smell to attract others.
(Ii) Attractiveness to partner
Pheromone is also used to attract males to mate. Female cockroaches emit pheromones and attract groups of male cockroaches. Humans can smell these pheromones, but for us, it is just an unpleasant smell. Dead cockroaches also emit another odor called death. The stench of death is due to oleic acid produced by the carcass of cockroaches. This smell can be used as a warning signal to other cockroaches, indicating that there is a death threat around the area.
mulberry
Ootheca is also generally considered a sign of infection. This is because the presence of ootheca indicates that there are cockroaches nearby.
Cockroach reproduction method
There are three breeding methods, among which the eggs are hatched according to the type of cockroach
1.Oviparous（American, brown banded and oriental cockroach）
Egg species squeeze their ootheca and store them near food sources. Sometimes, shortly after the egg is formed (brown), the female saliva through her mouth to stick it to the surface. One or two days after deposition, embryonic development (egg development) continues, and the egg changes from an egg shape to hard, from light brown to black. Ootheca of the egg species is usually hard and hard because it helps protect the eggs from dry (dehydration) America, and the Oriental and Brown banded cockroaches are egg species.
2.Oviparous（German cockroach, Madagascar hissing cockroach）
In contrast to oviparous, ovoviviparous in the abdomen of a female cockroach keeps its ovaries until it is ready to hatch. Due to slight differences in embryogenesis, ovoviviparous animals are divided into two categories:
(A) Pseudo-oocyte
The false ovarian organism will first squeeze out the ovary, rotate it and absorb it back into the uterus. This must be done in order for embryogenesis to occur. During embryogenesis, the eggs will have enough yolk to develop and they will receive water from the mother. When the nymph is ready to hatch, the ootheca will be completely squeezed out. If it is not squeezed, the nymph will come out of the female abdomen. Therefore, compared with oviparous eggs, the ovaries of pseudo-ovary species are relatively thin, less rigid and water permeable. One of the common species that use this spawning mechanism is the German cockroach.
(B) Real egg birthmark
A true ovo-fetal species does not develop eggs, but deposits eggs directly from the fallopian tube into the brooding sac in a random manner. During embryogenesis, the egg has enough yolk for development and will obtain water from the mother. An example of a true oviparous species is the Madagascar hissing cockroach.
3.viviparous（Pacific Beetle Cockroach）
Unlike oviparous and ovoviviparous, viviparous is a highly evolved egg-laying mechanism in cockroach species. The reason for this comes from the high-nutrient "milk" produced by the mother to the embryo; this is an uncommon phenomenon in cockroach species.
Fetal species tend to have small oocysts and are usually partially extruded and retracted into the uterus. The egg is wrapped in an incomplete membrane. During embryogenesis, the egg does not have enough yolk and water to fully develop. However, during pregnancy, the embryo can obtain high-protein "milk" from the mother through the uterine wall called pleuropneumonia. Using this highly evolved spawning mechanism is Pacific Beetle Cockroach.
Cockroaches can live for a week without a head because they have an open circulatory system that allows them to breathe through the small holes in each body part. Therefore, they do not rely on their mouth or head to breathe. The cockroach died a week later, because it had no mouth, it could not drink water and would die of thirst.