walnut leafhopper injury

Leafhopper injury on walnut. Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

Updated: March 24, 2021

About leafhoppers

leafhoppers mating
Leafhoppers mating on hibiscus leaf. Photo: J.A. Davidson, UMD
  • Adults of most leafhoppers are one-eighth to one-fourth inch long, slender and hold the wings roof-like over the back.
  • Many have angular, pointed heads.
  • Immature leafhoppers, or nymphs are similar to the adults but smaller with short wings.
  • Most pest leafhoppers are green with some color banding.
  • There are one or more generations a year depending on the species.
adult leafhopper
Adult leafhopper. Photo: J.A. Davidson, UMD

Leafhopper damage

  • Most leafhoppers feed on the upper surface of terminal leaves.
  • They feed by sucking chlorophyll from leaves.
  • This feeding activity results in coarse, white stippling.
  • The feeding activities of some species produce curling and stunting of terminal leaves.
  • Cottonwood, willow, honeylocust, dogwood, hawthorn, birch, cherry, and apple may be damaged.
  • Other species may transmit xylem-fastidious bacteria capable of causing scorch-like symptoms on elm, oak, red maple, and red mulberry.

Management  

  • Small shrubs and trees may be protected with sprays of a registered insecticide if honeydew or stippling is a problem.
  • Concentrate sprays where leafhoppers feed, usually on new growth. 
  • To manage bacterial leaf scorch, prune out infected branches below symptoms and improve tree vigor with standard cultural practices.
  • Over-fertilization may increase leafhopper populations.