Potato leafhopper, Empoasca fabae,> is being found in Illinois, with numerous populations in southern and central Illinois on ornamental plants. Potato leafhoppers attack many landscape trees, including crabapple, birch, ash, and maple. Red maples are highly susceptible, whereas silver, sugar, and Norway maples are more tolerant.|
Potato leafhoppers have piercing-sucking mouthparts, which they use to feed within the vascular tissues of plants. During feeding, potato leafhoppers inject a toxic fluid into plant tissue. Feeding, especially on maples, results in stunted tree shoots and leaves that curl downward, with brown edges. On other plants, such as ash, feeding creates small white or yellow spots on leaves, resulting in a stippled appearance because potato leafhoppers, like spider mites, remove chlorophyll (green pigment). Potato leafhoppers donít overwinter here because their eggs are sensitive to cold temperatures. They winter in the Gulf of Mexico and are blown north into Illinois by prevailing winds from early May to early June.
Potato leafhopper adults settle into alfalfa fields during the spring migration; and after the first cutting of alfalfa, they migrate onto ornamental plants. Adults are small (about 1/16 inch long), wedge-shaped, and pale green, with white eyes. Females lay eggs into the veins on the underside of leaves. The eggs hatch in 6 to 9 days into light green nymphs that are found on the underside of leaves and tend to move sideways when disturbed. Nymphs may undergo five instars before molting into adults. Adults and nymphs are similar in appearance except that the adults are larger, have wings, and can fly. The wings are held rooflike over the body. Empty, white, cast skins on the underside of leaves provide evidence of potato leafhopper activity. There may be as many as three to five generations per year.
Insecticides must be applied before potato leaf-hoppers cause plant damage. Control can be obtained with pyrethroid-class insecticides, such bifenthrin (Talstar), cyfluthrin (Tempo), lambda-cyhalothrin (Scimitar), and permethrin (Astro). If damage has already occurred, insecticide applications prevent further damage, and new growth appears normal beyond the damaged leaves. Regular scouting helps minimize the potential for potato leafhoppers to cause severe foliar damage.