Types of pesticides and matters needing attention in their selection

1.1 Inorganic pesticides are classified according to their composition and source, such as lead arsenate, calcium arsenate, arsenite, sodium fluoride, sodium fluorosilicate, sulfur, zinc phosphide, etc. Organic pesticides. Natural organic pesticides can be divided into plant insecticides (such as ivy, pyrethrum, tobacco, turpentine, anistemisin, azadirachtin, etc.) and mineral pesticides (such as diesel emulsions, petroleum emulsions, etc.). Synthetic organic insecticides include organochlorine pesticides, organophosphorus insecticides, organic nitrogen insecticides, pyrethroids insecticides and so on. Microbial insecticides, such as Bacillus thuringiensis, yellow tiger granulosis virus, Helicoverpa armigera granulosis virus, cabbage worm granulosis virus, Plutella xylostella granulosis virus, Beauveria bassiana, Alternaria alternata and so on. 1.2 the stomach poison is divided according to its function or effect, and the plant tissue or poison bait with the agent is eaten by the mouthparts of the pest and absorbed by the digestive system of the pest, thus poisoning the pest to death. Such as acephate, trichlorfon and so on. Contact agent, a chemical that enters the insect body from the epidermis, feet, antennae, valves, etc., after contact with a pest, poisoning and killing the pest. Such as malathion and other organophosphorus pesticides, pyrethroid insecticides and so on. Fumigant. Chemicals can volatilize into toxic gases at room temperature, or produce toxic gases through certain chemical reactions, which enter the body through the respiratory system such as the valve of pests, resulting in the poisoning and death of pests. Such as methyl bromide, phosphine and so on. Internal inhalant, which can be absorbed by plant roots, stems, leaves and other tissues, and transmitted to other parts of the shoot, or absorbed by seeds to seedlings and even various parts of the plant, the dosage is enough to poison the harmful pests. Such as methamidophos, methyl isathion, methyl thiocarbophos and so on. A repellent. The agent itself is non-toxic to kill pests, but it has a special smell, so that pests are avoided, so as to achieve the purpose of protecting crops from harm. Such as camphor balls. Antifeedant. The application of pesticides on crops can destroy the normal physiological function of pests and the secretion of digestive enzymes in the digestive tract, interfere with the nervous system of pests, make the pests refuse to eat, and finally make the insects starve to death and atrophy gradually. immortal insects can also have physiological atrophy. Such as chlordimeform, a variety of terpenoids (such as azadirachtin) and so on. Attractant is a kind of agent that can trap all kinds of pests and kill them. What is widely used is a very small amount of sex attractant released by female insects, which can induce the same kind of male to mate. When this sex attractant reaches a certain content in the air, it will make the pests disoriented, reduce mating, spawning and reproduction, so as to reduce the harm of pests. Such as cotton bollworm sex attractant, red bollworm sex attractant, big borer sex attractant, Plutella xylostella sex attractant and so on. Sterile agent, when insects come into contact with or take this agent, it destroys the function of its reproductive organs and makes it lose its reproductive ability, resulting in female insects mating but not laying eggs, or the eggs laid can not hatch normally, even the hatched offspring can not reproduce normally, so that the number of the population is reduced, or even extinct within a certain range. Such as substitute pie, thie pie and so on. Specific insect growth regulators. These agents mainly interfere with and destroy the normal metabolism of pests and inhibit chitin synthesis, resulting in deformity or death of larvae. At present, many organic synthetic pesticides have several insecticidal effects at the same time. For example, most organophosphorus pesticides have both stomach toxicity and contact toxicity; most pyrethroid pesticides have stomach toxicity, contact toxicity and repellent effect. These insecticides, which have multiple insecticidal effects, can be called comprehensive insecticides. 1.3 according to its toxicity, it is divided into highly toxic and highly toxic agents. Such as parathion, methyl parathion, phosphoramine, methamidophos, isocarbophos and so on. Medium and low poison. Such as acephate, triazophos, propiophos, fenitrothion, quinathion, pyridazine, chlorazophos, fenvalerate, cis-fenvalerate, deltamethrin, cypermethrin, cis-cypermethrin, cypermethrin, cyhalothrin, cypermethrin, Bacillus thuringiensis, Beauveria bassiana, tobacco, fennel, etc. (2) like other commodities, there are also many problems in the selection and purchase of insecticidal goods, which consumers should pay attention to when buying. In addition, pesticides are a special commodity, which involves a lot of knowledge and technology, and consumers should be more careful when choosing and buying them. Do not buy pesticides that are not marked with insecticidal active ingredients. Among chemical insecticides, pyrethroid insecticides are recognized to be relatively safe, while organochlorine, organophosphorus and carbamates are less safe than the former. Among many pyrethroid insecticides, the safety is also different, and permethrin, permethrin, permethrin and deltamethrin are generally safer. Do not buy insecticidal products produced by insecticide processing that have been explicitly prohibited. When leaving the factory, aerosol pesticides and other products should strictly implement the "three certificates" system indicating the quasi-production certificate number, the pesticide registration certificate number and the product quality standard number, otherwise they are illegal commodities and cannot be purchased. Foreign insecticidal commodities entering our market should also be carefully identified and should not be blindly trusted. (3) precautions in the use of pesticides should be restrained as far as possible, but do not use as much as possible when not in use. Minimize contact with insecticides, such as not staying in the room where the pesticide is applied, leave immediately after application and open the doors and windows an hour and a half later after full ventilation and exhaust. Do not let infants and children with immature brain development be exposed to pesticides, so as to avoid adverse effects on children's brain development. Be extra careful when using pesticides in the kitchen so as not to contaminate food, kitchen utensils, etc. Take a bath and change clothes after applying insecticide and insecticidal EC.