First-crop alfalfa harvested at the proper time usually escapes damage. Typically, the leafhopper builds up on the regrowth for the second crop, and can sometimes be a problem on the third crop. New seedlings, particularly before the first cutting, are often vulnerable to potato leafhopper. Severely damaged plants will be stunted and chlorosis will appear on all leaves if leafhoppers are not controlled. Alfalfa stands suffer yield and quality losses before any yellowing is visible.
Damage first appears on field perimeters.