Fenvalerate is a synthetic

pyrethroid A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (''Chrysanthemum cinerariaefolium'' and ''Chrysanthemum coccineum, C. coccineum''). Pyrethroids are used as commercial and hou ...

insecticide Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...

. It is a

mixture In chemistry, a mixture is a material made up of two or more different chemical substances which are not chemically bonded. A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the ...

of four optical

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Iso ...

s which have different insecticidal activities. The 2-S ''alpha'' (or SS) configuration, known as

esfenvalerate Esfenvalerate is a synthetic pyrethroid insecticide marketed under the brand Asana. It is the (''S'')-enantiomer of fenvalerate Fenvalerate is a synthetic pyrethroid insecticide. It is a mixture of four optical isomers which have different in ...

, is the most insecticidally active isomer. Fenvalerate consists of about 23% of this isomer. Fenvalerate is an insecticide of moderate

mammalian Mammals () are a group of vertebrate animals constituting the class (biology), class Mammalia (), characterized by the presence of mammary glands which in Female#Mammalian female, females produce milk for feeding (nursing) their young, a ...

toxicity. In laboratory animals, central nervous system toxicity is observed following acute or short-term exposure. Fenvalerate has applications against a wide range of pests including some of the more destructive such as the ''

Helicoverpa assulta ''Helicoverpa assulta'', the oriental tobacco budworm, is a moth of the family Noctuidae. ''H. assulta'' adults are migratory and are found all over the Old World Tropics including Asia, Africa, and Australia. This species has a brown coloured ...

''. Residue levels are minimized by low application rates. Fenvalerate is most toxic to bees and fish. It is found in some emulsifiable concentrates, ULV, wettable powders, slow release formulations, insecticidal fogs, and granules. It is most commonly used to control insects in food, feed, and cotton products, and for the control of flies and ticks in barns and stables. Fenvalerate does not affect plants, but is active for an extended period of time. Fenvalerate may irritate the skin and eyes on contact, and is also harmful if swallowed.

References

External links

Pyrethrins and Pyrethroids Fact Sheet - National Pesticide Information Center

* * ttps://web.archive.org/web/20040531224125/http://www.inchem.org/documents/pds/pds/pest90_e.htm WHO fenvalerate fact page {{insecticides Carboxylate esters Insecticides Nitriles Endocrine disruptors Chloroarenes Phenol ethers