Bifenthrin

Bifenthrin is a broad-spectrum pyrethroid insecticide widely used in agriculture to control foliar pests such as beetles, flies, heteropterans, homopterans, lepidopterans, and orthopterans in crops like cotton, corn, soybeans, and fruits. It acts primarily through contact and ingestion, with good residual persistence in the environment, making it effective against insect and mite infestations.

Common name (ISO): bifenthrine

Synonyms: FMC 54800 (development code); Talstar (commercial product brand)

Gross formula: C23H22ClF3O2

Number CAS: 82657-04-3

Chemical class: A type I (non-cyano) pyrethroid, classified as an insecticidal and acaricidal pyrethroid ester. It belongs to the family of synthetic pyrethroids, derived from natural pyrethrins, but with greater stability and persistence.

Release year: commercially introduced around 1984.

Development history: Bifenthrin was discovered and developed by FMC Corporation. Its development occurred in the 1970s as part of efforts to create insecticides that were more stable and effective than natural pyrethrins, which degrade rapidly in light. The synthesis involves a multi-step, solvent-free process, mixing 2-methyl-3-phenyl benzyl alcohol with a catalyst, heating until melted, adding cyclopropane methyl halide 3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl dropwise under negative pressure, and finishing with washing and separation. It was initially introduced in 1983 as a broad-spectrum insecticide, gaining popularity for its low water solubility and moderate volatility, which reduces leaching into the soil. FMC continued to improve formulations, such as in 2020 with versions of greater efficacy and lower environmental impact.

Mode of action: Bifenthrin is a sodium channel modulator in the central nervous system of insects, acting by contact or ingestion with a residual effect. It binds to sodium channels in nerve membranes, prolonging their opening and causing hyperexcitation, paralysis, and death of the insect. As a type I pyrethroid, it keeps the channels open for a shorter period than type II pyrethroids, resulting in symptoms such as tremors and convulsions. It is selective for invertebrates, with low toxicity to mammals due to rapid metabolism in the liver.

Patent numbers: US$4.238.505 and others