Flumethrin is a pyrethroid insecticide.[1] It is used externally in veterinary medicine against parasitic insects and ticks on cattle, sheep, goats, horses, and dogs,[2] and the treatment of parasitic mites in honeybee colonies.
Flumethrin is a complex mixture of stereoisomers. The molecule contains three asymmetric carbon atoms, there is cis-trans isomerism at the cyclopropane ring, and cis-trans isomerism at the carbon-carbon double bond of the alkene. So there are 16 different isomers. Commercial flumethrin typically contains 92% of the trans isomers on the cyclopropane ring and the cis-configuration at the olefinic carbon-carbon double bond and 8% of the isomer with cis geometry on the cyclopropane ring and the cis-configuration at the olefinic carbon-carbon double bond.[3]
Flumethrin is used in products, such as flea and tick collars, to protect pets against fleas.[4]
It is also used in the proprietary product, ″Bayvarol″, ″Polyvar Yellow″ which are veterinary treatments used by beekeepers against the parasitic mite Varroa destructor.