What are the four evils?

On February 1958 and 12, the Central Committee and the State Council issued the "Hygienic Instructions for Eliminating Four Pests". It is proposed that the task of eliminating flies, mosquitoes, rats and sparrows should be completed within 10 year. Gradually, sparrows were "rehabilitated" and replaced by bugs. Later, due to changes in social life, bugs were replaced by cockroaches. So it is finally determined that the "four pests" are flies, mosquitoes, mice and cockroaches.

1, fly

According to the statistics of flies in the late 1970s, there are more than 20,000 species of Diptera 132 families120,000 in the world, including more than 34,000 species of flies in 64 families. The main flies are housefly (right), city fly, Lucilia sericata and Chrysomya megacephala. The activity of flies is greatly influenced by temperature. It can only crawl at 4 ~ 7℃, fly at 10 ~ 15℃, feed, mate and lay eggs above 20℃, especially active at 30 ~ 35℃, stop moving at 35 ~ 40℃ due to overheating, and die at 45 ~ 47℃.

2.mosquitoes

The average life span of mosquitoes is not long, which is 3- 10 days for females and 10-20 days for males. Mosquito saliva contains a substance with vasodilating and anticoagulant effects, which makes it easier for blood to gather at the bitten place. The substance in mosquito saliva makes the bitten person's skin blister and itch. Mosquitoes suck about one thousandth of a milliliter of blood with each bite, and fly back to their birthplace to hibernate after each full meal. Mosquitoes usually move within 2 kilometers of their birthplace, but the farthest distance can reach 180 kilometers.

Step 3: Rats

The mouse is a kind of rodent, and its size is large and small. There are more than 450 kinds. Large number, fast reproduction, strong vitality, eat almost anything, can survive anywhere. He can dig holes, climb trees, climb mountains and wade. He wastes food and spreads diseases, which is extremely harmful to human beings, so he was beaten by human beings. Rats are easy to adapt to human living environment, so they become the main pests. Rats often haunt sewers, toilets, kitchens, etc. And move back and forth between the bacteria-carrying place and the clean place, and spread pathogens through the feet, body hair and stomach of rats.

4.cockroaches

For scavengers, they like to stay up at night and live in caves. It can stand the test of extreme heat and cold and is widely distributed. 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 is widely distributed in every corner of the world.

Extended data:

Mosquitoes can spread diseases such as malaria, Japanese encephalitis and dengue fever. It is necessary to do a good job in environmental sanitation and eliminate mosquito breeding grounds. According to the situation, choose screen doors, screens, mosquito nets, mosquito coils, pesticides and other anti-mosquito and anti-mosquito products to prevent mosquito bites.

Flies can spread diseases such as cholera, dysentery and typhoid. The effective way to control flies is to deal with the breeding environment of flies, such as bagging garbage (the bag should be intact and the mouth of the bag should be tightly tied), not littering, not defecating anywhere, and treating pet feces. Pay attention to take good care of food to prevent flies from biting and crawling, so as not to get sick. Fly swatter, fly lamp and fly paper (belt and rope) can be used to kill flies.

Rats can spread many diseases, such as plague, epidemic hemorrhagic fever and leptospirosis. It is necessary to do a good job in environmental sanitation and reduce the hiding places of rats; Collect food well to reduce the pollution of food by rats. You can use mousetraps, mousetraps, mousetraps and other mousetraps, and you can also use safe and efficient drugs to kill rats. Attention should be paid to the storage and use of rodenticides to prevent human and animal poisoning.

Cockroaches can spread diseases such as dysentery and typhoid fever, and protein in their excrement can also cause allergic rhinitis and asthma. Cockroaches mostly live in humid environment, and keeping indoor dry and clean can reduce the breeding of cockroaches. After eating, keep the food sealed, rinse the tableware with hot water, keep the stove clean, and clean the garbage on the ground and in the garbage bag in time. You can kill cockroaches with drugs or cockroach stickers.

References:

Baidu encyclopedia-four evils

References:

Baidu encyclopedia-mosquito