Pyrethroids
Pyrethroids
Insecticide Aerosol
Concentrated Insecticide
What are pyrethroid insecticides and how are they used?
 

Pyrethroids are a group of man-made organic compound similar to the natural pyrethrins, which is produced by the flowers of pyrethrums (Chrysanthemum cinerariaefolium and C. Coccineum). Pyrethroids now constitute a major commercial household insecticides. They are usually broken apart by sunlight and the atmosphere in one or two days, and do not significantly affect ground water quality. Pyrethroids are however toxic to aquatic organisms.

Mechanism of Pyrethroid
 

Pyrethroids are extremely popular for insecticide because exoskeletons of insects are sufficiently porous to pyrethroids. They are axonic poisons and cause paralysis of an organism. The chemical causes paralysis by keeping the sodium channels open in the neuronal membranes of an organism. The sodium channel consists of a membrane protein with a hydrophilic interior; this interior is effectively a tiny hole which is shaped exactly right to strip away the partially charged water molecules from a sodium ion and create a thermodynamically favorable way for sodium ions to pass through the membrane, enter the axon, and propagate an action potential. When the toxin keeps the channels in their open state, the nerves cannot de-excite, so the organism is paralyzed.

 

 

Pyrethroids for Crawling Insect

 

Cypermethrin, one of a handful of light-stable synthetic pyrethroids, is registered to control cockroaches, fleas and other indoor pests in homes, restaurants, hospitals, schools and food processing plants, and also in agriculture to control pests on cotton, fruits and vegetables. Compared to other pyrethroids, cypermethrin is relatively stable, with a half-life of 8-16 days in direct sunlight.It interacts with the sodium channels in nerve cells through which sodium enters the cell in order to transmit a nerve signal. These channels can remain open for up to seconds, compared to the normal period of a few milliseconds, after a signal has been transmitted. Cypermethrin also interferes with other receptors in the nervous system. The effect is that of long-lasting trains of repetitive impulses in sense organs."


Permethrin resembles pyrethrins chemically, but is chlorinated to increase its stability. There were 4 isomeric forms, two cis and two trans of technical permethrin. Compared to other pyrethroids, permethrin is very stable, even when exposed to ultraviolet light. Permethrin works as a contact insecticide, damaging the nervous system of insects which come in contact with it, leading to either their death or "knockdown". Ticks crawling across Permethrin-treated pant legs or socks are likely to drop off before they are able to attach and feed. One of the best things about Permethrin is its length of effectiveness per application. When applied to clothing by aerosol or trigger spray, Permethrin provides protection lasting up to two weeks or two washings, whichever comes first. Clothing soaked in Permethrin solution is effective for up to 4 months per application on stored garments.

 

A new synthetic pyrethroid imiprothrin (Pralle) with super knockdown activity has been developed for household use. The knockdown activity against cockroaches was much superior to that of conventional pyrethroids such as tetramethrin (Neo-pynamin) and prallethrin (Etoc). Pralle can be widely used as an aerosol for cockroach control. Moreover, the mixture with killing agent such as Gokilaht is also recommendable for its practical application. It has low acute toxicity to humans, but to insects it acts as a neurotoxin causing paralysis.


D-cyphenothrin (Gokilaht) has strong contact and stomach poisoning activity, good residual activity and a mild knock down against fly, mosquito, roach and other pests in public, in industrial area and household. It has spectacular expelling action to big roach such as periplaneta fuliginosa and periplaneta Americana. It is better than permethrin, fenpropathrin,  prallethrin and d-phenothrin in prevention of wool and furpests such as grain moth and achievies best in mosquito-repellent test by dipping mosquito net in liquids of d-cyphenothrin, permethrin, d-phenothrin. Fenpropathrin and fenvalerate respectively.


D-tetramethrin (Neo Pynamin Forte) can quickly knock down mosquitoes, flies and other flying insects and can repel cockroach well. It can drive out cockroach living in dark vift so as to increase the opportunity that cockroach contact insecticide. However, the lethal effect of this product is not so strong, Therefore it is often prepared with permethrin with strong lethal effect to aerosol, spray or tincture, which are especially suitable for insects prevention for family, public hygiene, food and warehouse.

 

Pyrethroids for Flying Insect

 

Sumithrin is an insecticide in the synthetic pyrethroid pesticide family. It is also called d-phenothrin. Marketed as an insecricide since 1977, mixture of 2 stereoisomers which are both insecticidally active. Sumithrin is primarily used to kill household insects, insects which pose public health problems (mosquitoes, for example), insects in stored grains and lice. Sumithrin kills insects by disrupting the transmission of nerve impulses along axons, the elongated parts of nerve cells. Synthetics pyrethroids allow excessive amounts of sodium atoms to enter nerve cells, stimulating the nerve cells and eventually causing paralysis.

 

Transfluthrin is a fast-acting pyrethroid insecticide with low persistency. It is a relatively volatile substance and acts as a contact and inhalation agent. Transfluthrin can be used in household and hygiene products, mainly against flying insects such as mosquitoes and flies, but also against material pests, such as moths. Transfluthrin is an effector on presynaptic voltage gate sodium channels in nerve membranes, causing knock down effects in insects.

 

Prallethrin is a synthetic pyrethroid with rapid knock-down activity against household insects pests. It is used in household insecticide products against mosquitoes and houseflies.

 

S-bioallethrin is a pyrethroid insecticide with a broad spectrum of activity, acting by contact and characteristized by a strong knock-down effect, it is active on most flying and crawling insects, in particula mosquitoes, flies, wraps, horners, cockroaches, flras, bug, ants, etc. Esbiothrin can be usedalone or combined with another insecticide, such as Bioresmethrin, Permethrin or deltamethrin and with or without a synergist(Piperonyl butoxide) in solutions.