Capable of being absorbed by plants into the plant sap, or by animals into the blood stream, without undue harm to the plant or animal; capable of poisoning insects feeding on the plant juice or animal blood. For example, a systemic insecticide can be applied to the soil, enter the roots of the plant, travel to the leaves, and kill insects feeding on the leaves.

a chemical absorbed by a plant or consumed by an animal which subsequently kills insects feeding in or within the treated organism

an insecticide applied to an organism (plant or animal) which is then translocated throughout its body tissues, thus rendering it poisonous to insects feeding on that organism; an insecticide that enters a plant through leaves, branches or roots and spreads throughout the plant in order to protect it from insects.