Spinosyn D aglycone is an acid degradation product produced by hydrolysis of both saccharide groups on spinosyn D, the minor component of the commercial insecticide, Spinosad. Spinosyn D aglycone is only weakly active as an insecticide as the saccharides are considered essential for potent activity. Despite the importance of spinosyns as agro-chemical insecticides and more recently as animal health products, there are few published reports of the biological activity or the levels of spinosyn D aglycone in animals or in the environment.