Sierra Natural Science SNS 209 Systemic Pest Control Concentrate supplies plants with a small amount of rosemeric acid, distributing it throughout the cell walls. When an insect starts to suck or chew on the plant and contacts the rosemeric acid, it stops eating and moves on. SNS 209 Systemic Pest Control is made up of 100 percent pure botanical extracts that are highly water soluble. The botanical extracts are all food-grade GRAS (generally recognized as safe) materials. 2.5 oz pouch makes 10 gallons.