How to deal with the rising resistance of common crop pests? Why resistance?

Drug resistance, also known as drug resistance, refers to the reduced sensitivity of pathogens and tumor cells to chemotherapy drugs. How to deal with the increase in drug resistance of common crop pests? Why does it develop drug resistance?

How to deal with the increase of drug resistance of common crop pests?

1. The resistance of rice brown planthopper and Chilo suppressalis is worrying.

The investigation data of the sensitivity of brown planthopper population to imidacloprid and buprofezin in the main rice producing areas showed that the resistance ratio of brown planthopper to imidacloprid and buprofezin was significantly higher than that in previous years. The resistance multiple was more than 100 times, and the sensitivity investigation to imidacloprid showed that it was in the middle to high level of resistance. Chilo suppressalis is resistant to chlorobenzamide and triazophos at low to medium level and to triazophos at medium to high level.

It is suggested that continuous and single use of insecticides should be avoided in the process of brown planthopper control, and insecticides with different action mechanisms and no cross-resistance should be used alternately and alternately between the upper and lower generations in the same area. It is suggested that the use of imidacloprid and buprofezin to control brown planthopper should be suspended temporarily, and the use of imidacloprid to control brown planthopper should be strictly restricted, and rice should be used once per season. Alternately, new insecticides such as imidacloprid, furosemide and fipronil were used alternately to delay the development of drug resistance of brown planthopper. In the prevention and control of Chilo suppressalis, attention should be paid to limiting the use of bisamides, silkworm toxins, avermectin and other agents in resistance areas, so as to avoid continuous contact with the same mechanism agents for multiple generations and curb the rising trend of drug resistance.

2. The resistance of Plutella xylostella and Plutella xylostella increased rapidly.

In vegetable producing areas, researchers monitored the resistance of Plutella xylostella to chlorobenzamide, fipronil, indenyl, avermectin and beta-cypermethrin, and the resistance of beet armyworm to chlorobenzamide and methoxyfenozide. The results showed that the resistance of pests in southern vegetable producing areas to common field pesticides increased rapidly compared with that in northern vegetable producing areas. It is heavy in the south and light in the north. The population of Plutella xylostella has developed high resistance to avermectin and cypermethrin, and moderate to high resistance to chlorobenzamide, fipronil and indenyl. The population of Plutella xylostella produced more than moderate resistance to chlorobenzamide and methoxyfenozide, and the resistance ratio was more than 15 times. The resistance level of Bemisia Tabaci population to new insecticides bromocyanoamide and snail ethyl ester has developed to a medium level, and the resistance ratio is more than 30 times.

Prevention and control countermeasures and suggestions: first, the drug use strategy should be adjusted in time, the alternating use of pesticides with different mechanisms should be implemented, and each type of pesticide should be used no more than once in vegetables per season, so as to slow down the development of drug resistance. The second is to use pesticides in strict accordance with the instructions for the use of pesticides to avoid excessive drug use and increase the frequency and concentration of use at will. Third, in view of the high level of resistance of Plutella xylostella population to avermectin and cypermethrin in most areas of China, it is suggested that it should be suspended and other agents with different action mechanisms such as ethyl spinosad, butyl ether urea and azadirachtin can be used alternately.

Why do common crop pests develop drug resistance?

1. The long-term continuous use of a certain pesticide to control certain pests or diseases will lead to a decrease in efficacy. In order to achieve the original control effect, the concentration of pesticide must reach many times of the original required concentration, this phenomenon is called the resistance of diseases and insect pests. At present, the phenomenon of drug resistance of insect pests is more common.

2. After a pest or pathogen develops resistance to a certain pesticide, it also has resistance to another pesticide that has not been used before. This phenomenon is called cross-resistance. Generally speaking, the same kind of pesticides are easy to produce cross-resistance, while different types of pesticides are not easy to produce cross-resistance because of their different killing principles to pests or pathogens.

3. The emergence of drug resistance is mainly caused by the continuous use of the same pesticide in the same area for many years to control this kind of diseases and insect pests. Because in the population of a pest, there are differences in drug resistance among individuals, after the application of pesticides, most of the individuals with weak resistance are killed, while a few individuals with strong resistance remain and continue to reproduce. So many times in a row "selection", after a stage of adaptation and variation, and finally formed a drug-resistant population.

4. Whether the pest really forms a drug-resistant population needs to be identified by scientific methods. Because there are many reasons for the poor control effect, such as pesticide quality, pesticide application technology and other problems, it can also reduce the control effect, which can not be regarded as the production of drug resistance.

5. In the use of fungicides, there is also the problem of drug resistance of bacteria. Many fungicides are used to control plant diseases, and their control effects are getting lower and lower. The formation of drug resistance of bacteria is similar to that of pests, and the control strategies are also the same.

At present, some areas have adopted the methods of increasing the concentration of pesticide application, increasing the amount of pesticide application, and increasing the number of times to resist drug pests and germs, which not only wastes pesticides and increases costs, but also is prone to drug damage, pesticide poisoning accidents and aggravating environmental pollution, and drug resistance will also become more serious, which should be paid attention to.