Pyrethrin is a natural insecticide. Naturally, it is slowly decomposed into water and CO. Therefore, pesticides or hygienic insecticides prepared by using it have no residual effects on humans and animals. Therefore, it is recognized internationally.
Since pyrethrin is composed of six substances with insecticidal activity extracted from pyrethrum, the insecticidal effect is good, insects are not easy to produce drug resistance, and can be used to kill highly resistant pests.
Pyrethrin has the central nervous action of paralyzed insects and is a contact insecticide, so it has a fast killing speed and is easily accepted by farmers.
It can be used as a sanitary spray for household hygiene and insecticide. It can be widely used in the pest control of economic crops such as green vegetables, green fruits and green tea. Pyrethrin inhibits nerve tissue. It is insoluble in water and easily soluble in various organic solvents.
Since pyrethrin is prone to cause dermatitis and even special allergies during production and use, it can be eliminated during the preparation of the product. It is toxic to aquatic organisms such as fish and bees. It has high insecticidal activity and belongs to nerve agents, which are mainly used for contact.
Pyrethrin has two functions of insecticide and environmental protection, which is incomparable to any chemical pesticide.
Its characteristics and advantages are:
(1) Low toxicity to mammals: Pyrethrin is one of the least toxic products of existing insecticides and can be metabolized quickly even if swallowed.
(2) Efficient broad-spectrum: Since pyrethrin contains a group of insecticidal components with similar structures, it has high-efficiency and broad-spectrum for insecticidal.
(3) The contact action is extremely strong, the mortality rate is extremely high, and the use concentration is low.
(4) Fast action: Pyrethrin has a contact effect of rapidly knocking down and blocking the death of the valve.
Pyrethrin is toxic to a variety of insects. For example, mosquitoes, flies, bedbugs and cockroaches, insects exposed to pyrethrins within 1 to 2 minutes, excessive excitement, movement disorders, rapid knockdown and paralysis.
Pyrethrin is a typical nerve agent, which acts directly on the excitable membrane and interferes with the ion conduction of the membrane, mainly affecting the sodium channel of the nerve membrane, delaying the disappearance of the increase of sodium conduction during excitation, causing the transmembrane sodium ion flow to prolong and cause the feeling. Nerve fibers and motor nerve axes repetitively move, transient neuronal depolarization and sustained muscle contraction. At high concentrations, it inhibits ion conduction in the nerve membrane and blocks excitation.
Pyrethrin is very toxic to mammals and is rapidly metabolized in the body without actually leaving a residue. But this only refers to oral administration. Intravenous injection of pyrethrin is highly toxic to mammals. The symptoms of poisoning in vertebrates are similar to those of insects. Excessive excitement and tremor are seen in a few minutes after administration.