A New Active Constituent of Pyrethrum Flower

Abstract

THE pyrethrin content as determined by the chemical process is the only factor that influences the market value of pyrethrum, as it is held that a close relationship exists between the amount of pyrethrin present and the number of insects killed. The results of our experiments (see graph) carried out with different samples of pyrethrum, clearly indicate that (1) the percentage kill of insects bears no direct relation to the amount of pyrethrin present in the samples, (2) a smaller amount of pyrethrin extracted from a sample yielding a high pyrethrin value produces better biological results than a larger amount from a poorer sample.