Is there a saying that cockroaches are pests?

cockroach

Pinyin: zhāngláng

Common name: Mrs. Huang

Scientific name: Blattella

Biological characteristics of cockroaches

Cockroaches are divided into Insecta and Cockroach. Sometimes called the family Blattidae.

Cockroaches are flat, dark brown and usually of medium size. Small head, move. Antennas are long and filiform, and compound eyes are developed. The wings are flat, the front wing is cortical, the rear wing is membranous, and the size of the front and rear wings is basically the same, covering the rear of the abdomen; Some species have no wings. Not good at flying, can run. Not completely perverted. Lay eggs in the egg sheath. There are about 6000 species (more than 2250 species), mainly distributed in tropical and subtropical regions. Live in the wild or indoors.

Insects such as cockroaches originated in Devonian, and scavengers prefer nocturnal activities and live in caves. It has withstood the test of extreme heat and cold and is widely distributed so far. Cockroach is one of the oldest insects on the earth, and once lived in the same era as dinosaurs. According to fossil evidence, primitive cockroaches appeared on the earth about 400 million years ago in Silurian. The cockroach fossils we found or cockroaches found in coal and amber are not much different from cockroaches in various cabinets. For hundreds of millions of years, its appearance has not changed much, but its vitality and adaptability have become more and more tenacious, and it has been widely distributed in every corner of the world until today. It is worth mentioning that a decapitated cockroach can live for 9 days, and the cause of death after 9 days is excessive hunger.

Edit this strange cockroach.

According to the ecological habits of cockroaches, a biologist once came to a conclusion: if there is a global nuclear war on the earth one day, all creatures in the affected area, including humans and even fish, will disappear, and only cockroaches will continue their lives! This is because under normal circumstances, the radiation that the human body can bear is 5 rem, and once the total radiation exceeds 800 rem, it will die. Blattella germanica can tolerate 9000~ 105000rems, and Periplaneta americana can tolerate 967500rems! So cockroaches can survive even if there is a nuclear explosion. At present, the U.S. government spends1500 million dollars to eliminate cockroaches every year, which is about twice the budget for AIDS prevention and control.

Most of them look the same, but if you look closely, you can still see the difference. At present, taxonomists divide cockroaches into about 6,000 species, of which about 50 species are pests, such as common Asian cockroaches. In addition, Periplaneta americana, Blattella germanica, brown cockroach and Australian cockroach are also widely distributed. There are about 200 species in China, and the common indoor cockroaches are about 10, which varies from place to place. Blattella germanica and Periplaneta americana are common.

Periplaneta americana is 30 ~ 50 mm (up to 2 inches) long, reddish brown, and lives outdoors or in a dark and warm indoor environment (such as a basement or a room with a stove). The adult period is about 1.5 years. Female worms can lay 50 or more eggs, and each pod contains about 16 eggs. After 45 days, the nymphs hatch. The nymph stage is 1 1 ~ 14 months. American cockroaches are native to tropical America and subtropical America. They have well-developed wings and can fly long distances.

Blattella germanica is a common indoor pest. Light brown with two black stripes on the chest, the female lays eggs 3 days after mating and carries them for about 20 days. Small size, about 12 mm (less than 0.5 inch) long, so it is often taken home by bagging or boxing in grocery stores. Shipped to all parts of the world. It can produce three or more generations a year. German cockroaches are abundant around the water pipes of croton aqueduct in new york, so they are commonly known as croton bugs.

The cockroach (Supella supellectilium) is similar to Blattella germanica, but slightly smaller. The wings of the male body are well developed, the body color is slightly lighter than that of the female body, and the wings of the female body are short and have no function. There are two light stripes on the back of both sexes, and the life span of adults is 200 days. There can be two generations every year. Eggs can be laid in clothes, planks or cracks in the floor. With the emergence of houses with heating equipment, brown-banded cockroaches also appear in cooler areas.

The oriental cockroach is considered as the dirtiest domestic pest. The body is oval, black or dark brown, shiny and 25 ~ 30 mm long. Life history is similar to that of American cockroaches. The male wings are short and developed, and the female wings are degraded. Originated in Asia and distributed to all temperate regions with merchants' vehicles.

Cockroaches have chewing mouthparts and can chew food. Cockroach's food is very complicated, ranging from ordinary food to brushes for shoeshine, including wire rubber, cardboard, soap, paint scraps, dead leaves, textiles, leather, hair and so on. Entomologists have found that there are 12 species of cockroaches that can live on paste for one week, while American cockroaches can live for one month only by drinking water, and for three weeks without eating or drinking. When food is short or space is crowded, cockroaches will devour each other. Cockroaches are good at crawling, swimming and flying in times of crisis. Cockroaches are good at living in tiny cracks because of their flat bodies. As long as there is water and food, they can live almost anywhere. If the conditions are not good, you will not die if you don't eat or drink for a long time. With the appearance of the above characteristics, the number and distribution range of cockroaches are increasing day by day, and they have become the number one household pest.

Cockroaches like the dark and fear the light. They like to go out at night on their stomach during the day and occasionally see them during the day. Generally, after dusk, they start to climb out for food and return to their nests in the morning. The temperature is the most active at 24~32℃, and it is completely inactive at 4℃. In the tropics, cockroaches can breed and move all year round. In northern China, if the indoor temperature is suitable in winter and there is heating equipment, cockroaches can move and reproduce as usual. Cockroaches are mostly oviparous, and their eggs are arranged orderly in the egg sheath, which can resist the influence of adverse environment and is not easy to be killed by chemical drugs. When conditions are suitable, they can hatch larvae. Cockroaches have a strong reproductive ability. After the male and female cockroaches mate, the female cockroaches will grow a pod-like thing on the tail, called an egg sheath, in which the eggs are laid. A few females can produce more than 10 and more than 90 egg sheaths. In an egg sheath, at least 10 cockroaches can be hatched, and at most more than 50 small cockroaches can be hatched, which is related to the species of cockroaches. In the eastern United States, there are more than 1000 cockroaches living in an average house; And a pair of Blattella germanica can breed 100,000 offspring in just one year! It takes about 15 days for the eggs of cockroaches to hatch in the egg clip. The newly hatched cockroach is a milky nymph without wings. Like other kinds of insects, it must shed its skin during its growth. After molting for 3~4 times, you can see the wing buds. Blattella germanica needs 6~7 molts to reach the adult stage of sexual maturity, while Periplaneta americana needs 10~ 12 times. The growth and molting time of cockroaches are closely related to climate factors and food acquisition. Usually this process is completed within two months. Most cockroaches living in the wild feed on decaying organic matter or litter. Cockroaches living in houses like starchy food. They often leave pathogenic organisms on the food they climb and spread diseases. Cockroaches have the bad habit of eating, spitting and excreting, polluting food and spreading many diseases, such as dysentery, paracholera, hepatitis, tuberculosis, diphtheria, scarlet fever and ascariasis. No matter what kind of cockroach it is, the pathogens it spreads are typhoid Bacillus, dysentery Bacillus, Escherichia coli, tuberculosis Bacillus, anthrax Bacillus, gall fungus and eggs of tapeworms, ascaris, schistosomiasis and so on. Cockroaches also secrete and excrete odorous substances, which make people feel sick and even vomit after smelling them. The Thai government has announced that it will no longer allow the sale of a "giant cockroach" originating in Madagascar in the name of a pet, and it is also prohibited for ordinary individuals to own it.

Cockroaches are moderate in size, easy to raise and have strong reproductive ability, and have long been the favorite experimental objects of biologists. Cockroaches are domestic pests that lie down during the day and come out at night. During the day, cockroaches mostly hide in the corner of the kitchen, in the gap of the cupboard, and go out to find food at night. Cockroaches eat almost everything, fragrant, smelly, hard and soft. Sometimes it will eat the paste in the spine and bite the book; Get into the TV and radio and bite the wire sheath; It even bites the baby's skin and fingers. It also eats feces, sputum and small animal carcasses. It excretes feces while eating, which makes the body dirty, carries germs, pollutes food and spreads various diseases, such as paratyphoid fever, dysentery, tuberculosis and acute hepatitis. Cockroaches are omnivorous insects that eat almost everything, not just meat and vegetables. They are all kinds of snacks, especially those that are spoiled and fermented. Garbage, feces, animal carcasses, bread, cakes, steamed bread, clothes, books, fur, Chinese herbal medicines, soap, from clothes to garbage, and even the paste on books are all cockroach food. Water is also essential for cockroaches.