Pyrethroids


Also found in: Dictionary, Medical.

Pyrethroids

 

synthetic esters of chrysanthemumic acid; analogs of pyrethrins.

Pyrethroids are obtained either by the reaction of chrysanthemumyl chloride with an alcoholic moiety in the presence of a tertiary amine or by transesterification of the ethyl ester of chrysanthemumic acid in the presence of sodium. The pyrethroids that are most toxic to insects are esters of cyclopentenolones, of substituted benzyl alcohols, and of N-hydroxymethylimides.

Pyrethroids produced today include allethrin (2-allyl-3-meth-yl-2-cyclopenten-4-oI-l-onyl chrysanthemumate), furethrin (2-furfury 1 -3-methyl -2- cyclopenten - 4 -ol -1 - ony 1 chrysanthemum-ate), cyclethrin (2-cyclopentenyl-3-methyl-2-cyclopenten-4-ol-1 -onyl chrysanthemumate), barthrin (6-chloropiperonyl chrysanthemumate), dimethrin (2,4-dimethylbenzyl chrysanthemumate), and tetrametrine [N-(3,4,5,6-tetrahydrophthalimido)-methyl chrysanthemumate]. These compounds, usually in the form of aerosols, are used against household insects.

REFERENCES

Mel’nikov, N. N., and K. D. Shvetsova-Shilovskaia. “Sintez insektitsidov piretrinovogo riada.” Khimicheskaia promyshlennost’, 1955, no. 3, pp. 50–61.
Volkov, Iu. P., and N. F. Shugal. “Sinteticheskie analogi piretrinov. Khimicheskaia promyshlennost’, 1969, no. 9, pp. 14–19.
Chemie der Pflanzenschutz- und Schädlingsbekä mpfungsmittel, vol. 1. Edited by R. Wegler. Berlin, 1970. Pages 87–102.

K. D. SHVETSOVA-SHILOVSKAIA

References in periodicals archive ?
The report, Global Pyrethroids Market 2015-2019, has been prepared based on an in-depth market analysis with inputs from various industry experts.
The objective of this study was to evaluate this new bioassay technique and determine baseline susceptibility to a number of commonly used pyrethroid and organophosphate insecticides in 2 sand fly species, P papatasi and P duboscqi (Neveu-Lemaire), which are relevant to US military operations in the Middle East and Africa.
An increase in the urinary levels of two pyrethroid metabolites (3-PBA and cis-DBCA) in children is associated with a significant decrease in their cognitive performances , particularly verbal comprehension and working memory.
Pyrethroid exposure was assessed by testing urine samples for a metabolite of several pyrethroids called 3-phenoxybenzoic acid (3-PBA).
However, data on the human health effects of pyrethroids (particularly neurodevelopmental effects) at the lower environmental doses encountered by the general public are limited, and data on developing children are particularly sparse.
However, because only pyrethroids are currently available for impregnating bed nets, and use of alternative insecticide classes for indoor residual spraying often result in higher program costs (14,15), resistance management options are severely limited.
Use of deltamethrin or other pyrethroids still remain a choice for vector control till an effective alternative insecticide is available for vector control for management of insecticide resistant vectors.
It is therefore essential to only apply a pyrethroid spray where it is absolutely necessary in order to prevent the spread of resistance.
Resistance to the pyrethroids deltamethrin and lambda-cyhalothrin was demonstrated.
5% of the tested bats; organophosphate compounds (primarily diazinon) were detected in 30%; pyrethroids in 12.
com The king of bug sprays, each squirt lasts for up to 10 hours and discourages midges, thanks to a formula combining natural pyrethroids and DEET.
1) Reasons for this are increasing restrictions in the use of organophosphate and organochlorine insecticides, the greater selectivity of pyrethroids for certain target species, (2) their moderate acute oral toxicity in vertebrates and humans, (3) and relatively low levels of environmental residues due to rapid degradation outdoors.