Spinosad is an insecticide made from a soil bacteria discovered in the Caribbean. Dow AgroSciences owns the patent on spinosad, and produces a variety of garden insect sprays containing the insecticide. Spinosad products have low human toxicity.
Spinosad is a nerve toxin. Insects ingest the toxin and die within 1 to 2 days. Spinosad also works as a contact insecticide.
Spinosad garden sprays are effective against caterpillars and potato beetles. The insecticide is moderately effective against thrips, aphids, flies and leaf hoppers.
Plants do not readily absorb spinosad spray insecticides, so insects must contact fresh droplets for maximum killing power. Formulations that contain penetrating ingredients help plants absorb small amounts of toxin, increasing the length of time it remains effective.
While spinosad is safe to use around people, pets, and wildlife, it can kill foraging honeybees. It is also toxic to beneficial trichogramma wasps. Once dry, spinosad is safe for these beneficial insects.