Apple Leafhopper: Appearance, Territory, Damage, and Life Cycle
Latin Name: Empoasca Maligna
Appearance: The most common leafhopper found on apples in the Pacific Northwest is the white apple leafhopper. Until the mid-1970s, when it became a significant pest in Washington, particular control methods were rarely required. Leafhoppers are significant pests of apple trees. White apple leafhoppers, rose leafhoppers, and potato leafhoppers are widespread pests in mature orchards, but the potato leafhopper is the most destructive to new plantings.
The adults of the white apple leafhopper and the rose leafhopper seem remarkably similar. Adults are long and slender, with a wedge-shaped body and a convex back. The body is a pale yellow, with a little darker head. White apple leafhopper nymphs have no distinguishing features, whereas elder rose leafhopper nymphs have a few little black spots on the black of the thorax and wing pads. The apple leafhopper (Empoasca Maligna) creates pale apple foliage speckled with white dots. Adult insects are greenish-white in color and have a preference for either apple or rose as a host.
Hosts Plants: The apple leafhopper feeds on apple, cherry, and prune trees, but has also been observed on peach and hawthorn. It typically does not harm the pear, although the rose leafhopper has been observed in large numbers on this crop.
Territory: The apple leafhopper is native to North America and can be found across the fruit-growing regions of the United States and Canada, but its pest status varies by region.
Damage Insect Cause: Apple Leafhoppers are leaf eaters and do not attack fruit directly. White apple leafhoppers have piercing-sucking mouthparts and cause leaf damage by piercing mesophyll cells and sucking the contents out. The ensuing leaf damage appears as a white or yellowish-white stippling. The leaves get speckled with white dots when the sap is drained from them. They may also reduce fruit quality by depositing little feces patches on apples. Leafhopper injury, like other types of foliar damage, can limit leaf photosynthesis, affecting the tree’s capacity to set, grow, or mature a crop of fruit.
Life History and Habits: These insects spend the winter as eggs beneath the bark of 1- to 5-year-old tree twigs. The presence of the eggs is indicated by crescent-shaped swellings in the bark. The eggs hatch around the time of the tight cluster stage (late March to mid-April), and the nymphs eat for several weeks. Adults can be seen flying by late May and can be monitored until frost kills them. In September, overwintering eggs are laid. Every year, there are two generations.