 Spinosyn A is slow to penetrate to the internal fluids of larvae; it is also poorly metabolized once it enters the insect.The apparent lack of spinosyn A metabolism may contribute to its high level of activity, and may compensate for the slow rate of penetration.Spinosad has high efficacy, a broad insect pest spectrum, low mammalian toxicity, and a good environmental profile, a unique feature of the insecticide compared to others currently used for the protection of grain products.