Insecticidal activity of the pyrethrins and related compounds IV.—Essential features for insecticidal activity in chrysanthemates and related cyclopropane esters

A range of 5‐benzyl‐3‐furylmethyl cyclopropane carboxylates and other esters are evaluated against house‐flies, mustard beetles and two mosquito species. The results show the importance for activity of a gem‐dimethyl group on the cyclopropane ring and that substitutions at C3 give wide variations in insecticidal activity and marked species specificity. Some of the compounds had considerable knockdown activity against houseflies, but the structural requirements for this type of action differ markedly from those for kill. RESP-6378