What is the source of allethrin?

Allethrins are compounds used in household insecticides like mosquito coils because they have low toxicity for humans. They are sourced from chrysanthemum flowers, found in Asia and eastern Europe. These plants are cultivated for ornamental, culinary or insecticide-preparation purposes. The flowers are pulverized and the allethrin compounds found in the seed cells are extracted and sold to insecticide makers.