What is the Difference Between Permethrin and Pyrethrin

The main difference between permethrin and pyrethrin is that permethrin is a synthetic chemical insecticide, whereas pyrethrin is a natural insecticide derived from chrysanthemum flowers.

Permethrin and pyrethrin are two common insecticides. Both have low toxicity to mammals, including humans.

Key Areas Covered

1. What is Permethrin 
     – Definition, Structure, Function
2. What is Pyrethrin
     – Definition, Structure, Function
3. Similarities Between Permethrin and Pyrethrin
     – Outline of Common Features
4. Difference Between Permethrin and Pyrethrin
     – Comparison of Key Differences

Key Terms

Permethrin, Pyrethrin

What is Permethrin

Permethrin is a synthetic chemical insecticide. It belongs to the pyrethroid family of insecticides, which are synthetic versions of naturally occurring pyrethrins derived from chrysanthemum flowers. This chemical compound belongs to pyrethroid esters. Its molecular formula is C₂₁H₂₀CL₂O₃. It is composed of 21 carbon atoms, 20 hydrogen atoms, two chlorine atoms, and three oxygen atoms. Pyrethrin has a complex structure that consists of a cyclopropane ring, a phenyl group, and an ester linkage.

The chemical structure of permethrin consists of two isomers – cis permethrin and trans permethrin. The cis – permethrin isomer has two chlorine atoms on the same side of the cyclopropane ring, while the trans-permethrin isomer has them on opposite sides. These isomers differ in their insecticidal activity and persistence.

Permethrin plays a major role in agricultural pest management. It is employed to control a variety of crop-damaging pests, including aphids, beetles, caterpillars, and leafhoppers. By effectively managing these pests, permethrin helps to minimize yield losses and maintain the quality of agricultural produce. In the field of public health, permethrin is utilized to combat disease-carrying insects, particularly mosquitoes and ticks. It is commonly used for treating mosquito nets, curtains, and clothing to provide protection against malaria, dengue fever, Zika virus, and other mosquito-borne diseases.

In veterinary medicine, permethrin is useful in controlling parasites and pests that affect livestock and companion animals. Permethrin is also a common ingredient in household insecticides, including sprays, aerosols, and foggers. It targets and eliminates crawling insects like ants, cockroaches, spiders, and silverfish. Permethrin is widely used for personal protection against insect bites. It is used to treat clothing, camping gear, and outdoor equipment to create a barrier that repels and kills various biting insects.

What is Pyrethrin

Pyrethrin is a natural insecticide derived from chrysanthemum flowers, specifically Chrysanthemum cinerariifolium and Chrysanthemum coccineum. Pyrethrin has low toxicity to mammals and is able to quickly break down in the environment, making it an appealing choice for pest management in various applications.

Chemically, pyrethrin is a mixture of six closely related compounds known as pyrethrin I and II. These compounds, pyrethrin I to pyrethrin VI, are esters with a cyclopropane ring, an alcohol group, and an acid moiety. The presence of esters in pyrethrin’s chemical structure contributes to its insecticidal properties and stability. It acts on the nervous system of insects by targeting voltage-gated sodium channels, which are essential for proper nerve impulse transmission. Then, pyrethrin binds to these channels and disrupts the normal functioning of the nervous system, leading to paralysis and, ultimately, the death of the insects. Furthermore, this mode of action is specific to insects, meaning that pyrethrin poses minimal risk to humans and other mammals.

Pyrethrin is widely used in organic farming and integrated pest management programs to control various pests such as aphids, beetles, moths, and leafhoppers. It offers an effective and environmentally friendly option for reducing crop damage and improving yields. Pyrethrin is a common ingredient in household insecticides, particularly those targeting crawling insects like ants, cockroaches, and spiders. Pyrethrin is also utilized in public health programs for controlling disease-carrying insects. Pyrethrin’s rapid breakdown and low toxicity make it suitable for use in areas where humans are present. Moreover, pyrethrin is useful in veterinary medicine for the control of fleas, ticks, mites, and other parasites, affecting livestock and companion animals.

Similarities Between Permethrin and Pyrethrin

• Permethrin and pyrethrin exhibit strong insecticidal properties.
• Both have low toxicity to mammals, including humans.
• Both permethrin and pyrethrin degrade relatively quickly in the environment.

Difference Between Permethrin and Pyrethrin

Definition

Permethrin is a synthetic chemical insecticide, whereas pyrethrin is a natural insecticide derived from chrysanthemum flowers.

Persistence

Moreover, permethrin has a longer residual activity than pyrethrin.

Toxicity

Permethrin exhibits higher mammalian toxicity compared to pyrethrin.

Stability

Permethrin is more stable than pyrethrin, mainly in the presence of light and heat.

Conclusion

Permethrin and pyrethrin are both insecticides. The main difference between permethrin and pyrethrin is that permethrin is a synthetic chemical insecticide, whereas pyrethrin is a natural insecticide from chrysanthemum flowers.

Reference:

1. “Pyrethrins.” NPIC – National Pesticide Information Center
2. “Permethrin Cream – Uses, Side Effects, and More.” WebMD.

Image Courtesy:

1. “Pyrethrin I 3D BS” By Mplanine – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Permethrin MT 20200909” By Mplanine – Own work (CC BY-SA 4.0) via Commons Wikimedia