W.H. Perron, Richter's Catalogue Botanix Rotenone and Pyrethrum Rotenone and pyrethrum are two effective, broad spectrum insecticides that are relatively safe to use. Both are extracted from plants, although synthetic pyrethroids are now on the market. These chemicals are rapidly broken down by light, heat and contact with air. Gardeners should also consider that the chemical groups of these two pesticides are not known to be carcinogenic as are organophosphates and carbamates, two groups to which many synthetic pesticides belong. Rotenone and pyrethrum are very toxic to cold-blooded animals, including fish, so they should not be allowed to contaminate waterways.
Rotenone is also very toxic to pigs.