During the Memorial Day weekend, I noticed many potato leafhoppers being drawn to porch lights during the evening hours. Adult leafhoppers arrive in Illinois each spring on prevailing winds from southern states. Soon after they find stands of alfalfa, they begin to feed, and females start laying eggs. In most fields, densities of potato leafhoppers do not increase to economic levels until after the first cutting. However, as soon as the first cutting is made, feeding by leafhoppers on regrowing alfalfa can be quite damaging. We recommend that scouting for potato leafhoppers in alfalfa should begin immediately after the first harvest. It only takes 0.2 leafhoppers per sweep to cause economic damage to regrowing alfalfa (0 to 3 inches). Spring-seeded alfalfa is especially susceptible to injury caused by potato leafhoppers. As we move through the leafhopper "season," we will provide frequent updates.--Mike Gray|
Potato leafhopper adult.
Hopper "burn" caused by potato leafhoppers.