What are the commonly used pesticide insecticides? A detailed explanation of deltamethrin and methyl parathion

(1) Parathion

Also known as 1605, it is a broad-spectrum highly toxic insecticide. It has strong contact, stomach and fumigant action, and good ovicidal effect, but no systemic translocation.

Parathion is a brownish-yellow oily liquid, unstable to ultraviolet light and air. Inside and outside living plant tissues, it decomposes relatively quickly due to the action of sunlight and enzymes. It persists longer on inanimate objects, with a residual period of 4-5 days on leaves. Its killing power against bees and natural enemy insects is also strong. The commonly used concentration is a 1000-1500 times dilution of 50% emulsifiable concentrate. It generally gives very good control of the jujube looper and the jujube leafroller.

(2) Methyl parathion

Also called methyl 1605. A brown oily liquid, poorly soluble in water, soluble in ethanol and acetone. It is relatively stable in neutral and acidic media, and decomposes rapidly when encountering alkaline substances. It has contact and stomach action, and a certain fumigant effect.

The residual period of methyl parathion on green leaves is 12-36 hours, and it can persist for several days on inanimate objects. Its main targets are the jujube leafroller, jujube geometrid and others.

(3) Phoxim

A pale yellow oily liquid, stable in neutral and acidic media, and easily decomposed by alkali. It degrades relatively quickly in sunlight. Under dark conditions it degrades more slowly. The residual effective period is 2-3 days.

Phoxim has very strong contact and stomach action, with no systemic action. It has contact and fumigant action against bees. It is a high-efficiency, low-toxicity, low-residue pesticide. It has the best killing effect on the jujube leafroller, is also especially effective against Lepidoptera larvae, and gives good control of the tortoise wax scale, fruit flies and storage pests. The commonly used concentration is a 1000-1500 times dilution of 50% phoxim.

(4) Malathion

The pure compound is a colorless liquid, stable in neutral media, decomposes quickly when encountering copper and aluminum, easily soluble in organic solvents, and slightly soluble in water.

This pesticide mainly has contact and stomach action. In the pest's body it can be oxidized to the more toxic malaoxon, thereby exerting a stronger insecticidal performance. Its main targets are fruit borers and leaf-eating Lepidoptera pests. The concentration used is a 1000-1500 times dilution of 50% malathion emulsifiable concentrate.

(5) Dimethoate

It is a high-efficiency, low-toxicity organophosphorus insecticide. It is a commonly used systemic insecticide. After the pesticide is absorbed by the plant, it is transported with the flow of water in the tree body to various organs such as roots, stems, leaves, flowers and fruits, but it does not affect the plant's normal physiological functions. When pests gnaw on the plant organs, they are killed by the pesticide liquid and die of poisoning.

Dimethoate not only has a very strong systemic insecticidal effect, but also good contact and stomach action. It is a broad-spectrum, high-efficiency, low-toxicity insecticide commonly used by fruit growers. However, on jujube trees, dimethoate is very sensitive to jujube leaves and easily causes phytotoxicity, so dimethoate is generally not used on jujube trees; instead, omethoate is used.

The targets of omethoate are leafroller pests and mites. The commonly used concentration is a 20000 times dilution of 40% omethoate. To prevent pests from developing resistance, it should be used alternately with other pesticides.

(6) Carbaryl

Also known as carbaryl. This pesticide is non-irritating, odorless, does not pollute the environment, is stable in nature, and has a long residual effect.

Carbaryl has contact, stomach and weak systemic action. It can control more than 150 kinds of pests and can be mixed with many pesticides. It cannot be mixed with alkaline pesticides. The usual concentration is a 400 times dilution of 50% carbaryl. Its target is scale insects.

(7) Deltamethrin

It is a high-efficiency insecticide artificially synthesized by imitating the pyrethrins in plants of the Asteraceae family. It has the characteristics of quickly knocking down insects, low toxicity and low residue.

This pesticide easily decomposes and loses effectiveness in alkaline solution, is stable to light in acidic and neutral media, and is easily soluble in acetone, ethanol, benzene and others. This pesticide has a wide range of targets, a small dosage, and rapid insecticidal action. It is mostly used for pests of Lepidoptera, Hemiptera, Homoptera and Hymenoptera; only its control effect on mites and the cotton boll weevil is relatively poor. Generally, its efficacy on jujube trees is extremely good, with dosage concentrations of a 60000 times dilution for controlling the jujube looper, 5000 times for the peach fruit borer, and 4000 times for the tortoise wax scale. However, long-term use of pyrethroid insecticides not only has a poor insecticidal effect on mites, but also kills the natural enemies of mites, easily causing mite resurgence and causing serious harm to jujube-producing areas.