Causes of insect resistance, pests develop resistance, how to avoid pests from developing resistance

Doctrine of the formation of pest resistance:

1 Selection theory: There are a small number of resistant individuals in living organisms, from sensitive strains to resistant strains, which are only the result of the selection of agents.

A large amount of drugs are used to mutate the insect genes. Once a resistant variant is generated, it can be passed on to future generations, resulting in a gradual increase in the number of resistant insects. The emergence of drug resistance is closely related to insufficient dosage and long-term blind use of pesticides, and rational drug use is the focus of preventing and reducing drug resistance.

Therefore, when we buy pesticides, we also need to buy different insecticides, and every time we spray, the dosage is also different, and we must match it before spraying, so as to avoid it.

It should be watered and fertilized in a timely manner, and the management of water and fertilizer should be strengthened, and the field management should be strengthened, and some pesticides should be sprayed regularly.

First of all, it is necessary to choose the appropriate medicine according to different pests, and then it is also necessary to change it in turns, and you can also choose to mix and maintain, or you can also use the drug indirectly when using the drug, and then you can also choose a scientific way to spray pesticides.

In the process of planting crops, there will always be some unsatisfactory things, such as repeated diseases or some insect information, at this time we definitely need to use some pesticides, but after the use of pesticides for a long time, there will definitely be some resistance, for the emergence of resistance, we must find some ways to avoid drug resistance or drug resistance, we must find other ways, other drugs to target. <>

Rotational medication has to be said to be a good way to use pesticides and avoid developing resistance. For example, if you have developed resistance to this contact type of pesticide, then I can use an endogenous type to avoid resistance. Because there are many types of pesticides, the simplest classification of pesticides is that there is a contact type and an endogenous type, and the characteristics of their pesticides are different, so it is not easy to develop resistance.

Even if the insects are resistant to the systemic type, then we can replace the pesticide and use the contact type, which can have a good killing effect. <>

Although some of today's pesticides are relatively simple, we can avoid the development of resistance through subsequent mixing and processing. As a simple example, we use this slow insecticide and an acute insecticide to make a pesticide that inhibits the growth of insects, so that it can be very good to avoid the development of resistance. Mixed pesticides such as trichlorfon and dichlorvos or malathion are often used, and when this pesticide is mixed together, it tends to be more effective at killing insects.

For pests that have developed resistance, we can add some synergists, which can activate pesticides, enhance the effect of pesticides, and avoid insects from becoming resistant. Nowadays, pesticides will more or less have some synergist additives, these additives and synergists are to make the effect more significant, so they will have a better effect on insecticides.

According to the personal information, do not use a single pesticide to control a certain pest for a long time, so as to cut off the formation process of pest-resistant populations. Pesticides with different mechanisms of action should be selected as far as possible for the varieties used in rotation. The principle of insecticide is different and can be used interchangeably.

The rotation of the same type of pesticide varieties should be cautious, because pests are easy to obtain cross-resistance, that is, after resisting a certain pesticide, it will also be resistant to other varieties of the same kind of pesticide.

Do not use a single pesticide to control a pest for a long time, so that the formation of pest-resistant populations can be cut off. Pesticides with different mechanisms of action should be selected as far as possible for the varieties used in rotation.

Different pesticides can be used to avoid pests becoming resistant to pesticides, as not reusing pesticides prevents pests from developing resistance to a single pesticide.

<> genetically modified organisms are not the only means of controlling pests, and genetically modified genes are usually a specific gene that works, and even if it is resistant, it will not become invincible to super pests. Although GMO is a very good way to get rid of pests and is the way forward, it is not the only way to get rid of pests at the moment. That is to say, even if the pests are now resistant to GMOs, we still have traditional pesticide control, we can also use the natural enemies of pests to control, and physical control such as insect traps, insect flukes and so on.

In addition, I have recently come into contact with a pest control method called the sterile insect technique, which uses radiation to produce a large number of sterile pest males, and after being released into the field, mating with the original female in the field will not produce the next generation, which can significantly reduce the population of the next generation.

Pests and diseases also evolve. For them, the environment in which we have sprayed pesticides is the harsh environment they have suffered; When faced with a harsh environment and an environment that needs to survive, their genes will change, produce evolution, and enhance their ability to adapt to the environment. Therefore, we can use medicine to kill most of the insect pests, but there will also be some fish that slip through the net, and after adapting to pesticides, they will develop resistance and reproduce offspring with antibodies, which will promote the effect of our pesticides to gradually decrease, or even lose their efficacy.

When faced with a harsh environment and an environment that needs to survive, their genes will change, produce evolution, and enhance their ability to adapt to the environment.

Therefore, we can use medicine to kill most of the insect pests, but there will also be some fish that slip through the net, and after adapting to pesticides, they will develop resistance and reproduce offspring with antibodies, which will promote the effect of our pesticides to gradually decrease, or even lose their efficacy. Resistance caused by the improper use of drugs by farmers themselves is not uncommon. Long-term single medication, arbitrary increase of drug concentration, and uneven drug use will cause resistance to pests and diseases.

In fact, resistance is regular, some drugs are relatively single, only resistant to a certain drug, which is relatively easy to manage, and some resistance will be resistant to several drugs, which is more troublesome. There are also some drugs that develop resistance to a certain drug, and then drugs of the same class as this drug also develop resistance.

The emergence of pest resistance is mainly caused by the use of the same pesticide in the same area for many years. There are many ways and means to control and overcome pest resistance, the most common method is to rotate the use of multiple pesticides, which has been proven to be the most effective way to overcome or prevent the development of resistance. In addition, the method of mixing pesticides can be used to overcome pest resistance.

Darwin called the process of survival of the fittest and the elimination of the unfit in the struggle for survival as natural selection Genetic variation is the basis of biological evolution, first of all, there are variations in the resistance of pests Some have strong resistance, some have weak resistance When using pesticides, kill the pests with weak resistance, which is called the elimination of the unfit; Pests with strong drug resistance survive, which is called survival of the fittest Pests with strong drug resistance survive, some of the breeding offspring have strong drug resistance, and some have weak drug resistance, when using pesticides, the pests with weak drug resistance are killed, and the pests with strong drug resistance survive In this way, after several generations of repeated selection, most of the pests that survive in the end are pests with strong drug resistance When using the same dose of pesticides, they can not play a good insecticidal role, resulting in the pesticide insecticide effect is getting worse and worse Therefore, after the long-term use of a certain insecticide in agricultural productionThe reason for the increased resistance of pests and the weakening of insecticidal effect is that insecticides have a selective effect on pests, so that pests with strong resistance are retained

Therefore, a

a. From the analysis, it can be seen that the drug-resistant individuals existed before the use of pesticides, and it was not the mutation induced by the pesticides, and a was wrong;

B. From the analysis of A, it can be seen that B is correct;

c. The selection of pesticides was changed to the frequency of resistance genes in the population base deficiency cause pool, and c was wrong;

d. Resistant insects do not necessarily exist in reproductive isolation from the original insects, so they are not necessarily new species and finch species, D is wrong

Therefore, b

The so-called pest resistance is the concentration and dose of a certain pesticide required when it is used to control a certain pest, which greatly exceeds the original required concentration and dose. In the control of mulberry insects, when trichlorfon pesticides were first used, lower concentrations have been effective, and now mulberry insect pests such as mulberry inchworms, mulberry caterpillars, weevils and other mulberry pests are controlled with trichlorfon pesticides, and the concentration has reached 800 1000 times, and these pests cannot be completely and effectively controlled. Pests develop resistance to pesticides, that is, they develop resistance.

The reason why pests develop resistance to a drug is mainly due to the continuous and long-term use of a drug for many years. In a large group of pests, the resistance to the agent is large and small, and the pests with great resistance will not die immediately when they encounter a certain agent, and the pests that remain under the action of the pest, after breeding, will slowly inherit this resistance to its offspring, and strengthen this resistance from generation to generation, and even the pests adapt to this agent, that is to say, they have produced resistance. On the other hand, because there are a variety of different enzyme systems in the insect body, some enzyme systems can be detoxified, such as the insect resistant to organophosphorus insecticides is mainly due to the enzyme system that decomposes organophosphorus in the body, such as the rice leafhopper resistant to malathion, which contains phosphatase and carboxylesterase, which can decompose malathion into a non-toxic body.

To overcome the resistance of pests, it is necessary to implement comprehensive control technology for the prevention and control of pests, that is, it cannot completely rely on chemical agents to control insects, but should be combined with biological control, agricultural technology control and other methods. In the use of pesticides, attention should be paid not to use a single pesticide for a long time and arbitrarily increase the concentration of pesticides. The alternating and mixed use of pesticides has a certain effect on delaying the resistance of insects.

For example, "diphosphine" is a 60% emulsifiable concentrate made of 40% trichlorfon and 20% malathion. This agent is currently effective in controlling mulberry pests.

Long-term, continuous use of the same insecticide in large quantities and in a single area can lead to the development of pest resistance. The following pest control principles should be adhered to to avoid or delay the development of pest resistance. The first is comprehensive prevention and control, which organically combines chemical, physical, biological and agricultural control, adjusts the layout of crops, improves the farming system, uses microorganisms and plant-derived pesticides as much as possible, overcomes the phenomenon of single use of chemical pesticides, and at the same time minimizes the use of chemical pesticides and the number of uses, and reduces the pressure on the selection of pests.

The second is to improve the way of pesticide application, first of all, strengthen the first forecast, select the right pesticides, and seize the critical period of medication. At the same time, concealed pesticide application, local pesticide application, interlaced pesticide application and other application methods are adopted to protect natural enemies and a small number of sensitive pests, so that pests are difficult to form pesticide resistant populations. The third is to alternate the use of drugs, alternate the use of agents with different mechanisms of action, and avoid the continuous use of a single agent to hinder the formation of pest-resistant groups.

Fourth, mixed drugs, drugs with different mechanisms of action are mixed, mixed and used, or processed into preparations. Fifth, the use of synergists and additives, synergists and insecticides can significantly improve the insecticidal effect, prolong the service life of insecticides. Sixth, zonal application, according to the distance of pest migration, different types of pesticides can be used in different directions.