Pyrethroids: classification and list of insecticidal drugs, how to use

Insecticidal substances belong to different chemical classes. Among them, a group of pyrethroids stands out. Consider the general characteristics and classification of substances, the principle of their work, the most common drugs from this group, the rules for using them. Handling precautions, toxicity and signs of poisoning.

General characteristics of pyrethroids

Natural pyrethroids are found in Dalmatian chamomile flowers, which is why this plant has long been used as an insecticide. Substances that are included in modern insecticides are obtained artificially.Like natural pyrethroids, they act on plant and stock pests, household pests, animal parasites.

Pyrethroids have a selective effect, their solutions are perfectly retained on the foliage and can partially penetrate into the middle.

Classification

Synthetic pyrethroids are divided into 3 groups (generations). Esters of chrysanthemic acid belong to the 1st. Substances are highly effective, but they quickly oxidize under ultraviolet radiation, so preparations with them must be used indoors. Esters are used to combat household insects, are part of plates and spirals, aerosols.

The 2nd generation includes substances that are more resistant to oxidation in the light. These substances are permethrin, cypermethrin, deltamethrin and fenvalerate. They are effective in small doses, pyrethroid preparations with active substances of this generation are used in agriculture for the treatment of crops from pests.They are also used from household insects, they process fabrics and containers. Disadvantages of 2nd generation pyrethroids - they are toxic to bees and fish, do not work against soil pests, and do not have a systemic effect.

3rd generation substances are photostable, minimally volatile, have a long residual effect, less toxicity, some can act against mites. This group includes cyhalothrin, imiprothrin, bifenthrin, fluvalinate, fenpropatrin.

Working principle

Pyrethroids - substances with contact and intestinal action, quickly penetrate the chitin of insects. They act on the central nervous system, first causing its overexcitation, then paralysis and death of pests.

The substances compare favorably with insecticidal compounds of other classes in that they can act in cool weather, so they can be used in early spring and late autumn.

Unlike FOS and carbamates, pyrethroid substances do not act on pests that live secretly, they are used mainly against leaf-eating species. The protective effect lasts 2-3 weeks, the waiting time before harvesting the fruit usually takes 3-4 weeks. If pyrethroids are used for a long time, insects may develop resistance to them, as well as to other insecticides.

To prevent resistance, it is necessary to alternate treatments with drugs from different groups, if the pyrethroids act already weaker, replace them with FOS, agents with neonicatinoids, carbamates or other active substances.

Most common drugs

Cypermethrin is included in the composition of the funds: "Arrivo", "Superkill", "Cirax", "Rangoli-Noril", "Cyperus", "Cytox", "Shaman", "Spark", "Inta-Vir" , Lightning Extra, Karbotsin.

Bifentrin is contained in the insecticides Procrop, Talstar, Volcano, Clipper, Zernospas, Imidalit, Pirinex Super.

Deltamethrin is part of the preparations "Decis Expert", "Atom", "Proteus", "Biorin", "Decis Profi", "Legion".

Permethrin includes Medilis-I, Medifox-Super, Akromed-U, Avicin.

General terms of use

Substances against pests are produced in different formulations. Sprays are used in finished form, a solution is prepared from powder, granules, concentrated liquid. Means with pyrethroids have a small rate and consumption. In the garden and in the garden, they can be used throughout the season, in everyday life - when pests appear. Number of treatments - from 1 time, repeat if necessary.

Precautions

Insecticides with pyrethroids belong to classes 2 and 3 of toxicity for humans and classes 1, 2, 3 for bees and fish. To work with them, you should always wear gloves, goggles, a respirator and protective clothing that covers the body from splashes of the solution.Spraying of plants should be carried out in calm, dry weather. If the solution gets on the skin, wash it off with water; if it gets into the eyes, also immediately rinse them with water.

Symptoms of poisoning

Active substances in pyrethroid insecticides can enter the body through the gastrointestinal tract, skin (even intact) and through the respiratory tract. They enter the adipose tissue and the brain, from where they are removed after a while.

According to the level of toxic effects, pyrethroid compounds are divided into 2 groups: substances in the formula of which there is no cyano group, and substances in which it is. The first cause muscle trembling, twitching, excitability. The second - convulsions, salivation. Symptoms of acute intoxication: itching and burning of the skin, severe weakness, pain in the head, temperature rise to 38-39 ° C in the first 2-3 days after poisoning.

When signs of pyrethroid poisoning appear, first of all, immediately finish the work, then carry out gastric lavage at home with plenty of water with activated charcoal.If the condition is serious, seek medical attention immediately.

Pyrethroids are one of the main insecticides used in agriculture and everyday life. They include substances of various structures that can fight against harmful insects. Destroy many types of insects that parasitize plants and animals, and some types of ticks.

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