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 pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. The major use of insecticides is in agriculture, but they are also used in home and garden settings, i ...

. It is a

mixture In chemistry, a mixture is a material made up of two or more different chemical substances which can be separated by physical method. It is an impure substance made up of 2 or more elements or compounds mechanically mixed together in any proporti ...

of four optical

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...

s which have different insecticidal activities. The 2-S ''alpha'' (or SS) configuration, known as esfenvalerate, is the most insecticidally active isomer. Fenvalerate consists of about 23% of this isomer. Fenvalerate is an insecticide of moderate

mammalian A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

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 4-Chlorophenyl compounds Phenol ethers