# Grape leafhopper

- URL: https://backyardgrapes.com/diseases/grape-leafhopper/
- Scientific name: Erythroneura spp.
- Category: Insect / pest
- Affects: Leaves
- Severity: moderate
- Favored by: Warm season with several generations; adults overwinter in leaf litter and weeds.
- Easily confused with: Spider mites

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

**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 — Cultural / prevention:**
- 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.

**Treatment — Organic / low-toxicity:**
- Insecticidal soap or horticultural oil aimed at the young nymphs.
- Conserve natural enemies, especially tiny Anagrus wasps that parasitise the eggs.

**Treatment — Conventional (chemical):**
- Insecticides only above a damaging threshold, targeting the first nymph brood.

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.)

**Image credits:**
- 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)](https://www.lcsun-news.com/story/life/2020/09/20/grape-leaves-looking-blotchy-might-western-grape-leafhopper/3487908001/)
- Adult western grape leafhopper (Erythroneura elegantula) on a grape leaf with stippling and tarspots — [Photo: Collin Gross, iNaturalist](https://www.inaturalist.org/observations/231762931) (CC BY-NC 4.0)
- Pale stippling on a grape leaf from western grape leafhopper feeding — [Photo: Eugene E. Nelson, Bugwood.org, Bugwood.org](https://www.ipmimages.org/browse/detail.cfm?imgnum=5360758) (CC BY-NC 3.0 US)

**Sources:**
- [Leafhoppers (Grape Pest Management Guidelines)](https://ipm.ucanr.edu/agriculture/grape/leafhoppers/) — UC IPM
- [Managing Grape Leafhoppers on New Mexico Grape Vines](https://pubs.nmsu.edu/_h/H332/index.html) — New Mexico State University Extension
- [Grape-Leafhopper](https://pnwhandbooks.org/insect/small-fruit/grape/grape-leafhopper) — Pacific Northwest Pest Management Handbooks (OSU / WSU / U. Idaho)
- [Biology, Ecology, and Management of Eastern Grape Leafhopper (Hemiptera: Cicadellidae), a Key Pest of Vineyards in North America](https://doi.org/10.1093/jipm/pmaa003) — Journal of Integrated Pest Management (Oxford Academic)