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Stability of contact insecticides. I—ultra-violet photolysis of the pyrethrins

✍ Scribed by R. E. Blackith

Publisher
John Wiley and Sons
Year
1952
Tongue
English
Weight
545 KB
Volume
3
Category
Article
ISSN
0022-5142

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✦ Synopsis

Abstract

In view of the discrepancy between the stability of pyrethrum‐in‐oil films in direct sunlight and in the dark, the persistence of such films under various conditions is reviewed, and the ultra‐violet photolysis is found to be by far the most active agent in decomposing such films. The action of ultra‐violet light on the insecticide is found to be independent of humidity or the presence of oxygen. Four processes are outlined by which the pyrethrins become inactivated. The prolonged residual effect of pyrethrum‐in‐oil films in the absence of light, established by earlier workers, is confirmed, and the decomposition is found to be independent of temperature, over the ordinary ambient range.

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Stability of contact insecticides. III—a
Stability of contact insecticides. III—allethrin, DDT and BHC in ultra-violet light
✍ R. E. Blackith 📂 Article 📅 1952 🏛 John Wiley and Sons 🌐 English ⚖ 528 KB

## Abstract Allethrin, the (±)allylrethronyl ester of (±)__trans__‐ and (±)__cis__‐chrysanthemic acids, is more stable to ultra‐violet photolysis than the natural pyrethrins. It is less well protected by benzeneazo‐β‐naphthol, so that the natural and synthetic insecticides have a similar stability