About Deltamethrin

The Butox^® range of formulations contains deltamethrin as an active ingredient. Deltamethrin belongs to the class of synthetic pyrethroids which resemble natural pyrethrins found in the pyrethrum plant.

Natural pyrethrins are unstable and rapidly degrade in contact with water, air and light. Synthetic pyrethroids are more potent than pyrethrins, have a better knockdown effect and are repellent. Pyrethroids are biodegradable but are stable in air and water. Some of the other more common pyrethroids used include bioallethrin, cypermethrin, fenvalerate, flumethrin, lambdacyhalothrin, phenothrin, and permethrin.

Pure isomer

Most of the synthetic pyrethroids are combinations of trans- and cis-isomers. The cis-isomer has greatest insecticidal activity. Deltamethrin is a pure cis-isomer and is thus a powerful insecticide.

A summary of the different pyrethroids and number of isomers present

Active ingredient	Number of possible isomers	Number of isomers in the commercial product	Number of active isomers in the commercial product
Alpha cypermethrin	8	2(4)	1
Cyfluthrin	8	8	2
Cypermethrin	8	8	2
Deltamethrin	8	1	1
Flumethrin	8	8	2
L-cyalothrin	4	2	2
Permethrin	4	4	2

 

Mechanism of action of Deltamethrin

Deltamethrin’s effect on the parasite is mainly through contact and ingestion. As deltamethrin is extremely lipophilic it easily penetrates the cuticles of insects and acarines.

Mechanism of action of pyrethroids in insects and invertebrates

Typical effects of deltamethrin are:

• Hyperexcitation
• Loss of coordination
• Tremors, convulsions, tetanic spasms
• Knock-down effect and dehydration
• Death