Learn about biology, talk about what biological control is, what its advantages are, and write one or two things you know.

Biological control is a method of using one organism to deal with another. Biological control can be roughly divided into three categories: insect control, bird control and fungal control. This is a method to reduce the population density of pests and weeds. It uses the relationship between biological species to suppress another or another creature with one or another creature. Its greatest advantage is that it does not pollute the environment, which is incomparable to non-biological pest control methods such as pesticides. There are many methods of biological control. Biological control is a control method that uses beneficial organisms or other organisms to inhibit or eliminate harmful organisms. Contents include: (

1) is controlled by microorganisms. Commonly used are fungi, bacteria, viruses and bacteria that can secrete antibiotics against biomass, such as Beauveria bassiana for controlling Dendrolimus punctatus (fungi), various Bacillus thuringiensis preparations for controlling various forest pests (bacteria), and virus crude extracts for controlling cypress, Dendrolimus punctatus and Paulownia moth. (virus), 5406 to control seedling blight (actinomycetes), microsporidia to control gypsy moth and other larvae (primary).

(2) Using parasitic natural enemies for control. There are mainly parasitic wasps and parasitic wasps, the most common ones are Trichogramma and parasitic wasps for controlling pests such as Dendrolimus punctatus, swollen-legged wasps for controlling longicorn beetles, and flower-horned aphids for controlling Hemiberlesia pitysophila.

(3) Using predatory natural enemies to control. There are many such natural enemies, mainly insect-eating, rat-eating vertebrates and predatory arthropods. Birds have different insect states of preying on pests, such as tits, grey tits and woodpeckers. Natural enemies of rodents such as weasels, owls and snakes. The predatory natural enemies of arthropods are insects such as ladybugs, mantises and ants, as well as spiders and mites. [5] [4] [3]

3 prevention and control methods

Use natural enemies

The method of using natural enemies to control pests is the most widely used. Each pest has one or several natural enemies, which can effectively inhibit the reproduction of pests. This inhibition is an important part of ecosystem feedback mechanism. Using this ecological phenomenon, we can establish a new equilibrium relationship between biological populations.

Organisms used for biological control can be divided into three categories:

Predatory organisms, including lacewings, ladybugs, walking insects, teratoids, amblyopia mites, spiders, frogs, toads, mosquito-eating fish, forktail fish and many beneficial insect-eating birds.

② Parasitic organisms, including parasitic bees and flies.

③ Pathogenic microorganisms, including Bacillus thuringiensis and Beauveria bassiana. In China, the control of citrus scale insects by red ladybug, soybean moth and corn borer by Beauveria bassiana, overwintering red bollworm by golden bee and sugarcane borer by red bee were all successful. [2] [ 1]

Resistant crops

That is, cultivating disease-resistant crop varieties to control pests and diseases, such as cultivating potato varieties resistant to potato late blight, sugarcane varieties resistant to mosaic disease, flax varieties resistant to Fusarium wilt, wheat varieties resistant to wheat stalk fly, etc., has achieved results. Insect resistance of crops is characterized by tolerance, resistance and lovelessness. Patience means that crops can maintain normal yield despite being attacked by pests; Antibacterial property means that crops can affect the growth and development or physiological function of pests, inhibit their vitality and development speed, and reduce the reproductive ability of female adults; Aphids mean that crops are not attractive to pests.

Farming control

Breeding control is to change the agricultural environment and reduce the occurrence of harmful organisms. The prevention and control of sterile insects is to collect or cultivate a large number of harmful insects, make them sterile with gamma rays or chemical sterile agents, and then release them to mate with wild pests, so that their offspring lose their reproductive ability. Florida, USA, used this method to kill curly flies. Gene control is to change the genetic composition of harmful insects, so that their offspring will be less active, less fertile or have genetic infertility. In addition, using some biological hormones or other metabolites to make some harmful insects lose their reproductive ability is also an effective measure of biological control. Biological control of pests and diseases does not pollute the environment and affect human health, and has broad development prospects. [4] [5]

4 History editing

According to "Southern Vegetation", people can often be seen selling a bag in the street in the south. This kind of bag is made of cushions. There are many branches and leaves in the bag, and insect cocoons are hung on the branches and leaves. Insect cocoons look like thin flocs, wrapped in an insect ant. The color of this insect ant is red and yellow, which is bigger than ordinary ants. Sell it with thin flocs. South China is rich in citrus, and there is a pest on citrus trees, which is particularly harmful to fruits. This insect ant is bought to control this citrus pest. If there were no such insect ants, all oranges would be eaten intact by pests. This record of using insects and ants to control citrus pests is the earliest known biological control.

In the Ming Dynasty, Chen Jinglun recorded in detail the process of his invention of raising ducks to control insects in his Notes on Controlling Locusts. Chen Jinglun was a great man. He once introduced sweet potatoes from Luzon Island in the Philippines to Fujian for trial planting. Later, he and his descendants actively devoted themselves to promoting sweet potato cultivation in various places. Chen Jinglun and his family are to a great extent responsible for sweet potato becoming the food of the general public.

Raising ducks to control locusts was invented by him in the process of popularizing sweet potato cultivation. One year, when Chen Jinglun was teaching sweet potatoes, he saw a swarm of locusts flying in the sky and ate up the potato Ye Quan. Then dozens of herons flew in and ate the locusts again. Inspired by this, he thought that ducks and herons had similar feeding habits, so he raised several ducks and put them in the place where herons lived. As a result, he found that ducks ate more locusts than herons, so he called on local people to raise ducks in large numbers. Every spring and summer, ducks are driven to the fields to eat locusts. Later, this method really became one of the important methods to control locusts in Jiangnan area, and many books on locust control also mentioned this method.

During the Ming and Qing dynasties, ducks were used not only to treat locusts, but also to treat cockroaches. Shrew is a kind of crab, which feeds on rice buds, so it has become one of the pests in rice fields. In the Ming Dynasty, people in the Pearl River valley began to raise ducks to prevent cockroaches from harming rice.

Raising ducks to control insects is the most widely used biological control technology in the history of China. It can not only eliminate pests, protect crops, but also promote the development of aquaculture and turn harm into benefit. This is a great invention in the history of biological control in China. [5] [ 1]

5 major cases

In the United States, Bacillus thuringiensis is used to control larch sawfly, gypsy moth and spruce leaf curl moth; In the Soviet Union, the use of nuclear polyhedrosis virus and granulosis virus to control Hyphantria cunea was also successful.

A team of scientists organized by Manila International Rice Research Institute studied the effects of pesticide use on rice and rice growers in the Philippines.

International researchers have a powerful weapon against the diamondback moth-a bee smaller than it. Plutella xylostella is the most destructive pest on Japanese crops. Its larvae devour cauliflower, cabbage, cauliflower, radish and Brussels sprouts. Plutella xylostella has adapted to chemical pesticides.

Bees, the natural enemies of Plutella xylostella, are so small that it is difficult to see them without a magnifying glass. When it lays eggs, it will lay eggs in the larvae of Plutella xylostella. When the bee eggs hatch into young bees, the young bees will eat the larvae of the diamondback moth. If a common natural pesticide that does not pollute the environment is used in conjunction with this pest control method, the effect will be better.

See Baidu Encyclopedia:

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