Pesticides are substances or organisms that prevent, destroy, repel or mitigate a pest. Sabadilla is considered among the least toxic of botanical insecticides. It can irritate eyes and produce sneezing if inhaled.
Pyrethrum is the most widely used botanical insecticide in the United States.
Pyrethroids are synthetic materials designed to imitate natural pyrethrum. They have the same basic chemistry but are modified to improve persistence, insecticidal activity, etc. Sulfur is probably the oldest known pesticide in current use. When we think of organic Gardening, we often conjure up the image of a crop grown free of any pesticides. However, the concept of organic Gardening is much more broad, and, believe it or not, many types of pesticides are permitted.