On June 5, I sampled an alfalfa field in Champaign County and found potato leafhoppers by using a sweep net. These small insects have the potential to cause injury to subsequent cuttings of alfalfa. Typically, the first cutting across much of Illinois is not at economic risk to this migratory pest. Producers are encouraged to scout their fields for potato leafhoppers and recognize that very low densities of these insects equipped with piercing and sucking mouthparts can cause economic losses to alfalfa soon after the first cutting. Densities as low as 0.2 leafhoppers per sweep in stands that have plants less than 3 inches in height can cause damage. Don’t wait too long for plants to begin greening up after the first harvest only to find leafhoppers have been hard at work. For more information about the identification, biology, life cycle, and management of potato leafhoppers, please refer to the Department of Crop Sciences fact sheet regarding this insect.