Abstract
The synergistic action of phenolic lactones on allethrin and pyrethrin were investigated from the mortality of synergized pyrethroids against rice-weevil by petri-dish method.
In the series of α-benzylidene-γ-butyrolactones, (±) hibalactone and α-piperonylidenebutyrolactone were appreciably synergistic on allethrin although less effective than piperonyl butoxide.(±) Hinokinin, 2-piperonylidene-3-piperonyl-1, 4-butanediol also showed week activation, but α-benzylidene-, α-anisylidene-, α-veratrylidene-butyrolactone, α-piperonylidene-α'-piperonyl-tetrahydrofuran, α-trimethoxybenzylidene-β-trimethoxybenzyl-butyrolactone were not synergistic on the insecticidal action.
In the series of synergized pyrethrin, (±) hibalactone and α-piperonylidene-butyrolactone showed week synergism but the other test compounds showed no appreciable synergism.
