TRANSLOCATION OF PYMETROZINE IN PLANTS

Pymetrozine, a pyridine-azomethine, is a selective biocide against aph ids, whiteflies and plant hoppers with a high plant systemic activity. By means of bioassays and autoradiographic techniques it has been sho wn that this systemic behaviour originates not only from xylem but als o from phloem mobility. After foliar application the growing points of plants are protected by pymetrozine imports mainly from leaves. This indicates a high importance of phloem mobility for the systemic activi ty of pymetrozine against plant-sucking insects.