INSECTICIDAL ACTIVITY OF PYRETHRINS AND RELATED COMPOUNDS .2. RELATIVE TOXICITY OF ESTERS FROM OPTICAL AND GEOMETRICAL ISOMERS OF CHRYSANTHEMIC, PYRETHRIC AND RELATED ACIDS AND OPTICAL ISOMERS OF CINEROLONE AND ALLETHROLONE

Department of Insecticides and Fungicides, Rothamsted Experimental Station, Harpenden, Herts. The relative toxicities of esters related to the natural pyrethrins and to allethrin were evaluated against Phaedon cochleariae (mustard beetle), Tenebrio molitor (yellow mealworm beetle), Dysdercus fasciatus (cotton stainer) and Plutella maculipennis (diamond‐back moth) and the results were compared with those of workers who used Musca domestica (housefly). With the insect species used here there were no outstanding reversals of the toxicity ratings established in the studies with M. domestica. However, the toxicities of the esters depended more on the nature of the alcohol when two acids were compared and on the acid component with different alcohols. (+)‐Allethrolone and (+)‐cinerolone gave more toxic esters than their optical isomers but there was less difference than had been found with other insect species between esters from trans‐and cis‐chrysanthemic acids. Copyright © 1969 John Wiley & Sons, Ltd