Backyard Grapes Identify & treat grapevine problems
Insect / pest moderate severity

Grape leafhopper

Erythroneura spp.

Small hoppers whose feeding stipples leaves white; heavy numbers scorch the canopy.

Blotchy, speckled upper surface of a grape leaf, a classic symptom of leafhopper feeding damage Photo: Marisa Thompson Las Cruces Sun-News (Southwest Yard & Garden column, NMSU Extension)
Adult western grape leafhopper (Erythroneura elegantula) on a grape leaf with stippling and tarspots Photo: Collin Gross iNaturalist CC BY-NC 4.0
Pale stippling on a grape leaf from western grape leafhopper feeding Photo: Eugene E. Nelson, Bugwood.org Bugwood.org CC BY-NC 3.0 US

Description

Grape leafhoppers are small, wedge-shaped insects that feed on the underside of the leaves, emptying cells as they go. The result is a fine white stippling that spreads until patches of the leaf look bleached; in heavy years the canopy browns and sheds leaves, which can slow ripening and leave fruit exposed. Disturb an infested vine and the adults and pale nymphs scatter in a little jumping cloud — a quick way to tell them from mites, which don’t move like that.

For most home growers, low leafhopper numbers do no real harm and are best tolerated, especially since tiny Anagrus wasps parasitise their eggs and often keep them in check. When populations climb, target the first generation of nymphs with soap, oil, or a threshold-based insecticide, and clean up the leaf litter and weeds where the adults spend the winter. (Note that some sap-feeding “sharpshooter” leafhoppers matter more as vectors of Pierce’s disease than for their feeding.)

What to look for

  • Tiny pale stipples that merge into bleached, whitened patches on the leaf.
  • Pale nymphs that scatter and hop when a leaf is disturbed; white cast skins on the underside.
  • Dark specks of excrement (tarspots) on leaves and fruit.
  • Heavy infestations brown and drop leaves, slowing ripening.

Treatment options

Cultural & prevention

Start here — habits that stop problems before they spread.

  • Clear leaf litter and weedy overwintering sites near the vines.
  • Keep the canopy open; dense shaded growth favours build-up.
  • Tolerate low numbers — vines shrug off light feeding, and natural enemies often keep pace.

Organic / low-toxicity

Gentler sprays and biologicals for active outbreaks.

  • Insecticidal soap or horticultural oil aimed at the young nymphs.
  • Conserve natural enemies, especially tiny Anagrus wasps that parasitise the eggs.

Conventional fungicide / pesticide

For severe cases. Always follow the product label.

  • Insecticides only above a damaging threshold, targeting the first nymph brood.

Sources

This entry is based on the references below. Read them for full detail and for spray timings and rates valid where you live.

  1. Leafhoppers (Grape Pest Management Guidelines) — UC IPM
  2. Managing Grape Leafhoppers on New Mexico Grape Vines — New Mexico State University Extension
  3. Grape-Leafhopper — Pacific Northwest Pest Management Handbooks (OSU / WSU / U. Idaho)
  4. Biology, Ecology, and Management of Eastern Grape Leafhopper (Hemiptera: Cicadellidae), a Key Pest of Vineyards in North America — Journal of Integrated Pest Management (Oxford Academic)