Leafhopper damage reduces alfalfa yield, hay quality and, in severe cases, stand life. At one time or another, almost every alfalfa field in the midwestern and eastern areas of Canada and the United States has suffered from leafhopper infestation. It is common for alfalfa producers to mistake leafhopper damage for moisture or heat stress, or boron deficiency, due to the characteristic yellowing symptom caused by leafhopper damage. The nymphs are similar in appearance but lack wings. Both adult and nymph stages cause damage to alfalfa.
Leafhoppers normally jump or crawl rapidly sideways when disturbed.
Leafhoppers are sucking insects and also excrete a toxin while feeding on the sap from alfalfa plants. The toxin is what causes the yellowing and stunts plant growth. Very young alfalfa plants and plants in early stages of regrowth are the most susceptible to leafhopper damage. Infestation is most likely to occur prior to the second and third cuttings of alfalfa in most areas, and in the first cut if it has been delayed. Warm, dry spring weather is much more conducive to leafhopper infestation than is cool, wet spring weather.