THE PYRETHRINS AND RELATED-COMPOUNDS .39. STRUCTURE-ACTIVITY-RELATIONSHIPS OF PYRETHROIDAL ESTERS WITH CYCLIC SIDE-CHAINS IN THE ALCOHOL COMPONENT AGAINST RESISTANT STRAINS OF HOUSEFLY (MUSCA-DOMESTICA)

Activities of a range of pyrethroidal esters, incorporating structural variations in all regions of the acid and alcohol components, have be en measured against two fully characterised and homozygous resistant s trains of Musca domestica L. (kdr and super-kdr). The results, limited in this paper to esters of alcohols with cyclic side chains, indicate uniform resistance to the kdr strain across the whole range of struct ural variations. Against the super-kdr strain, while variation in the acid component has little effect, the resistance factor is sensitive t o the nature of the alcohol component, in particular on whether it con tains an alpha-cyano substituent.