Permethrin (popular brand-name Dragnet) and bifenthrin (sold as Talstar) are the chemical names for insecticides known as synthetic pyrethrins, or pyrethroids. They are best used in fogs for restaurants, bug bombs and animal products given that they quickly dissipate. Pyrethrins are natural insecticides made from chrysanthemums. Synthetic pyrethoids are considered an improvement over natural pyrethrins and organophosphate and carbamate chemicals, which are more toxic. Permethrin and bifenthrin are much less harmful, says PestProducts.com. And these two synthetic pyrethrins appear to work equally well on pests, reports PubMed.gov.
Permethrin employed at the professional level, as in Dragnet, contains about 36 per cent of the chemically active ingredient. Dragnet is a popular insecticide created to have little odour and to be used very broadly for eradication of ants, cockroaches, bees and a range of other insects around lawns, gardens and homes. It's also effective against termites in house structures.
Bifenthrin, sold as Talstar, is popularly used as a broadcast insecticide for home and garden, targeting in particular ants, chinch bugs, molecrickets and ticks, among other ornamental and turf insects. Talstar comes in the form of a liquid concentrate that can be sprayed both outside and indoors.
Pyrethrins are natural compounds that have insecticidal effects. Some chrysanthemum plants naturally produce pyrethrins. Either the plant's flowers or oils can be employed against certain insects. In the case of the flowers, these are dried to a powder. Chrysanthemum oil is leached out of the plant using solvents. The resulting powder and oil contain 30 per cent of the active pyrethrin ingredient, according to Extension Toxicology Network.
Considered contact poisons, pyrethrins swiftly enter the nervous systems of the insects they target, paralysing the bug within minutes of dosing. The insect is immediately immobile. However, this so-called knockdown dose doesn't necessarily kill all insects in the case of natural pyrethrins. Certain treated pests will rally back and survive. Synthetic pyrethrins are more effective and at the same time less harmful to mammals than the natural variety. To ensure that all pests get knocked out for good when natural pyrethrins are used, it is recommended that carbamates, synergists and organophosphates be mixed with the pyrethrins.
Permethrin Versus Bifenthrin
In a 2007 study conducted by the "Journal of the American Mosquito Control Association," it was determined that bifenthrin and permethrin work equally well as barriers against mosquitoes when applied to military tents. Five tents were placed in the bushland of Queensland, Australia, about 1.5 miles from the coast. Two got bifenthrin and two got permethrin treatment. One tent served as a control. Protection was initially recorded as 77 per cent for the bifenthrin-sprayed tents and 84 per cent for the tents getting permethrin. That percentage difference is considered insignificant.