The potato leafhopper (Empoassca mali, LeB) is the most serious insect pest affecting the potato crop in Iowa, and probably in the Mississippi valley. Thru its feeding activities, it produces a pathological condition in the leaves of many of its host plants which is characterized by a distortion of the leaf veins, especially near the tip and a yellowing of the tissue supplied by them around the margin and at the tip. Often this yellowing is followed by a necrosis of the leaf tissue. Especially is this true on the potato and with this plant the burning is accompanied by a rolling upward and inward of the leaf margin.