Introduction to the characteristics of organophosphorus insecticides

Organophosphorus insecticides are the most widely used and most widely used insecticides in China, with a wide variety of varieties and different properties, but generally speaking, they have the following characteristics: (1) the insecticidal spectrum is wide. At present, some commonly used varieties of organophosphorus insecticides can control a variety of agricultural and forestry pests, and some can be used to control sanitary pests and ectoparasites of livestock and poultry. (2) the methods of killing insects are diversified, which can meet the needs of many aspects. Most varieties have contact and stomach toxicity, some varieties have internal action or penetration, and some varieties have fumigation effect, which can be applied in a variety of ways to control different types of agricultural and forestry pests, such as aboveground, underground, drilling, piercing, and so on. Its insecticidal mechanism is to inhibit the activity of cholinesterase in pests, destroy the normal conduction of the nervous system, and cause a series of nervous system poisoning symptoms until death. (3) the toxicity is high, so safety should be paid attention to when using it. Most varieties are highly toxic to humans and animals, and some varieties are highly toxic, such as methamidophos, methamidophos, internal phosphorus uptake and so on. When using it, we should pay attention to health and safety, and ensure that there is a certain safety interval before the harvest of agricultural products, so as to avoid pesticide residue poisoning. (4) it is easy to degrade in the environment. General varieties are easy to degrade into non-toxic substances in animals and plants, and in natural conditions, such as sunlight, wind and rain, they are easy to hydrolyze and oxidize. Therefore, it should be protected from light and moisture when storing. (5) easy to detoxify. Although organophosphorus insecticidal is highly toxic and easy to cause human and animal poisoning, some highly effective detoxification drugs such as atropine and antipralidoxime have been widely used. (6) the development of resistance is slow and complete to crops. Although organophosphorus insecticides have been used for a long time and their efficacy is lower than at first, the resistance of pests to organophosphorus insecticides develops relatively slowly and is still widely used. At the same time, it is generally safe to crops and is not easy to produce drug damage. of course, some agricultural products are more sensitive to individual varieties, such as trichlorfon on sorghum and omethoate of dichlorvos on corn and peach trees at high concentrations. (7) most organophosphorus pesticides are easy to decompose under alkaline conditions, so they can not be mixed with alkaline substances. At present, the main varieties of organophosphorus insecticides registered and widely used in China are: parathion, methyl parathion, methamidophos, acephate, isocarbophos, dimethoate, omethoate, dichlorvos, malathion, phoxim, monocrotophos, methamidophos, chlorpyrifos, triazophos, methyl isophos, trichlorphon, propiophos and so on.