What biological control of pests involves

The main contents of biological control include: the use of microbial control. Common applications of fungi, bacteria, viruses and antibiotics that can secrete antibiotics, such as the use of Beauveria bassiana (fungus) to control Masson pine caterpillars, Bacillus thuringiensis (bacteria) various variant preparations to control a variety of agricultural and forestry pests, virus crude extract (virus) to control cypress moth, pine caterpillar, paulownia bag moth, etc., 5406 (actinomycetes) to control seedling blight, microsporidia (protozoa) to control the larvae of dance moth, Taishan No. 1 (nematode) to control longhorn beetle.

Use parasitic natural enemies for control. There are mainly parasitic wasps and parasitic flies, the most common are red-eyed bees, parasitic flies to control pine caterpillars and other pests, swollen-legged wasps to control longhorn beetles, and flower horn aphid wasps to control pine round scales. Use predatory natural enemies for control.

There are many such natural enemies, mainly insectivore, rodentivorous vertebrates and predatory arthropods. These include lacewings, ladybugs, walking bugs, manatus mites, blunt mites, spiders, frogs, toads, mosquito-eating fish, forktails, and many insectivorous birds. There are different species of birds that prey on pests such as, grey magpies, woodpeckers, etc.

Natural predators of rodents such as weasels, owls, snakes, etc. In addition to insects such as ladybugs, praying mantises, and ants, there are also spiders and mites among arthropods.

1. Predatory natural enemies: There are many types of predatory natural enemies, among which the effect is better. Ladybugs and lacewings are commonly used.

Aphid-eating flies, insectivorous flies, insectivorous bugs, wasps.

Walking insects and predatory mites, such natural enemies generally eat a large number of insects, and in the process of their growth and development, they must eat several, dozens or even hundreds of insects to complete their development. Therefore, the rampant effect of controlling pests in nature is very obvious. For example, cotton fields should be used to control aphids and cotton bollworms with ladybugs, lacewings, and wasps.

have achieved certain results.

2. Parasitic natural enemies: This kind of natural enemies parasitize the body of pests, feed on their body fluids and internal organs, and kill pests, mainly including parasitic wasps and parasitic flies.

The biological control of pests mainly includes the treatment of insects with natural enemies and the treatment of insects with microorganisms, and the treatment of insects with natural enemies also includes: protection of natural enemies, reproduction and release of natural enemies, and introduction of natural enemies.

Protecting natural enemies and allowing them to multiply naturally requires specific measures to be developed according to the characteristics of various natural enemies in different environments. A good tillage practice can often produce a good effect of protecting and using natural enemies, such as cotton and wheat interplanting in North China, when wheat will be ripe, wheat aphids are becoming scarce; The cotton is in the seedling stage, and the cotton aphid is becoming more and more serious, which provides food for the natural enemies of the aphids on the wheat, and they have moved to the cotton seedlings, and the cotton aphid has been naturally controlled, and there is no need to take any control measures. Some farmers who did not interplant cotton collected natural enemies (such as ladybugs, lacewings, etc.) in the wheat fields and helped them move to the cotton fields. Some orchards protect natural enemies by planting beneficial plants, increasing orchard biodiversity, and improving the suitable environment for natural enemies.

Artificially propagating and releasing natural enemy insects are usually used when the number of pests is not enough to control the number of pests below the economic damage level after protecting the natural enemies in nature, so the control objectives are very clear, and the natural enemies used for breeding and release should be very targeted. The most researched and utilized in the breeding and release of natural enemies in China is a variety of egg-parasitic wasps of the genus Red-eyed Wasp, which have been commercialized and can be used to control the main lepidopteran pests.

The purpose of introducing natural enemies from other places is to improve and strengthen the composition of local natural enemies and improve the natural control effect of insect pests. This is often used to deal with newly imported pests.

Insects have a lot of pathogenic microorganisms can be used to prevent and control agricultural and forestry pests, some can also make insect populations produce epidemics, to achieve the effect of long-term control, most of the pathogenic microorganisms of insects are harmless to humans and animals, do not pollute the environment, after forming a certain preparation, can be sprayed like chemical pesticides, so it is often considered to be microbial pesticides.

After the garlic is mashed, soak for a while, then extract the juice and add 20-25 times of water, stir and filter for spraying, which can control aphids, red spiders and other pests, and the control effect can reach more than 90%; Kilograms of peppercorns, kilograms of water, boiling for 20-30 minutes, adding water 10 times after filtration for spraying, can control aphids, leafhoppers, whiteflies, armyworms, scale insects and other pests, the control effect is better.

First, peach leaf control method

1. Soak 5 kg of peach leaves and 100 grams of lime in 3 times of clean water for 5 hours, take the original solution after squeezing the peach leaves dry and remove the slag, add 10 kg of water to each kilogram of the original solution, and then spray to control cotton aphid, corn borer and rice bract.

2. In addition, peach leaves can be boiled and filtered, and the original solution can be sprayed to prevent and control rice leafhoppers and rice planthoppers.

Second, castor leaf control method

1. Grind the dried castor leaves into fine powder, mix them into the soil and spread them into the ground according to a certain proportion, which can prevent and control the harm of underground pests such as grubs, mole crickets and ground tigers.

Add 1 kilogram of castor leaf powder to kilograms of water, soak it for a period of time and then fill it with a kettle, which can control ground maggots, cabbage worms, leaf-eating beetles and other pests in leek, garlic, radish, cabbage and other planting areas.

3. In addition, castor leaf dry powder can be made into leaching solution and sprinkled on toilets, manure pits, etc., which has obvious control effects on fly maggots.

3. Garlic prevention and control method

Mash the garlic, extract the juice after soaking, add 20-25 times of water, stir evenly, filter and spray, can control aphids, red spiders, scale insects and other pests, the control effect can reach more than 90%, and can also inhibit diseases such as blast, cotton blight, small rust and soil tofu rot.

Fourth, cypress leaf control method

Take kilograms of cypress leaves, add kilograms of water, soak for one day, then heat and boil for 30-40 minutes, filter the waste residue to obtain the original solution. Each kilogram of stock solution mixed with water 80-100 kg spray, can control sorghum aphid, malt, cabbage insects and other pests, the insecticidal effect is about 85%, note that the stock solution needs to be stored for 3 days before use.

Fifth, the pepper prevention and control method

Take kilograms of peppercorns, add kilograms of water, boil for 20-30 minutes and then filter, and then add 10 times of water for spraying, which can control aphids, leafhoppers, whiteflies, armyworms, scale insects and other pests, and the control effect is more than 87%.

There are many methods of biological control, such as: the use of natural enemies or biological agents. This method is the most widely used.

Each pest has a variety of natural enemies, which can effectively inhibit the proliferation of pests. This inhibition is an important part of ecosystem feedback mechanisms. Using this ecological phenomenon, it is possible to establish a balanced relationship between new biological populations.

Use crop resistance to pests and diseases. That is, to promote resistant crop varieties and rational variety layout to control pests and diseases. For example, the promotion of potato varieties resistant to potato late blight, wheat varieties resistant to wheat straw flies, etc.

The advantage is that it is safe for humans and animals and does not pollute the environment. Natural enemy control of pests is a natural phenomenon, and paying attention to the protection and utilization of natural enemies in farmland ecology can maintain ecological balance and have a long-term inhibitory effect on pests. It does not develop resistance to pests. Natural enemies are potential natural renewable resources in farmland ecology, which can make full use of this abundant resource.

The disadvantage is that the insecticidal effect is slow, and most natural enemies have a narrow selection range of pests, and it is difficult to quickly take effect on rampant fulminant pests and multiple pests at the same time; The protection and utilization of natural enemies is technically difficult, and often requires artificial large-scale propagation, and after being released into the field, it will be affected by environmental factors such as climate.

(1) Insect control is the use of natural enemies and insects to control pests. The use of natural enemy insects to control pests should first improve the inhibition effect of local natural enemies on pests. Therefore, it is necessary to pay attention to the protection of the natural enemies of pests and try to create favorable conditions conducive to the survival of natural enemies of pests.

Sometimes, it is necessary to adopt artificial large-scale breeding and release of natural enemies of pests to increase the number of natural enemies and inhibit the occurrence and harm of pests.

2) Treating insects with bacteria is to use the pathogenic microorganisms of pests to control pests. The pathogenic microorganisms that cause insect diseases include fungi, bacteria, viruses and other groups. These pathogenic microorganisms can be artificially expanded and cultured in a simple and inexpensive way, and the biological agents can be sprayed in the field to kill the insects.

For example, BT emulsion (Bacillus thuringiensis emulsion) can control a variety of lepidopteran pests.

3) Use insecticide to control insects Insecticide is an active substance produced by some actinomycetes in metabolism. Japan obtains an acaricide from Streptomyces aureus, which is highly toxic to spider mites. The aphidicide produced in China has a remarkable effect on the control of aphids.

4) The use of parasitic nematodes and protozoa to control insects In China, nematodes have been used to control tigers and cotton bollworms, and initial results have been achieved.

5) Use predatory spiders and mites to control insects There are many species of spiders in vegetable fields that can prey on pests (only live insects, not dead insects). Spiders have strong fecundity, are not easy to die, have a high survival rate in nature, and are not subject to booby-trapping such as black lights, and there are thousands of spiders in general vegetable fields, so they do not need to be bred in captivity, and only need to be protected and utilized.