Resistance to Potato Leafhopper in alfalfa was discovered over 40 years ago but this trail has been slowly incorporated into alfalfa varieties and those available have been underused by farmers. This occurred because the first varieties with this trait had low levels of resistance and did not perform well in the field. Also this resistance is not complete; it raises the spray threshold and reduces the need for spraying but, if insect levels become sufficiently high, fields may still need to be sprayed. Later generations have had good resistant but some yield drag (reduced yield in the absence of the insect compared to nonresistant varieties). The latest generation of potato leafhopper resistant varieties has both good resistance and little yield drag (Table1).