Amorphous Tumours induced in Alfalfa by Potato Leafhoppers

Abstract

AN alfalfa (Medicago saliva L.) plant with many small tumours was found during tests for resistance to the potato leafhopper, Empoasca fabae (Harris). Most of the other plants expressed the usual symptoms of leafhopper injury described by Granovsky¹, Jewett², and Poos³. Those symptoms were wilted stems and leaves, shortened internodes and dwarfing, and reddening or yellowing of the foliage. This particular plant produced amorphous tumours at the sites of feeding as well as the usual symptoms of leafhopper injury. Since there have been no previous reports of the potato leafhopper causing hyperplasia in the forage legumes, we felt that the phenomenon should be described and that its possible implications with regard to the nature of leafhopper injury should be discussed. These findings could prove useful to scientists investigating abnormal growth in other organisms.