Beginner

Scientific Name
          Erythroneura comes (Grape leafhopper)
          Erythroneura tricincta (Three-banded leafhopper)

          Erythroneura, ziczac (Virginia creeper leafhopper)

Identification
In all species, adults are 3-3.5 mm long, move quickly and fly when disturbed.  All have 5 nymphal instars that are 2.2-2.5 mm long at maturity, appear similar to adults but do not have wings.

Grape leafhopper
Nymphs:

• Immature stages are pale white
• Lack pigmentation in the eyes
• As nymphs age, spots on back become darker
• Large nymphs have three pairs of pale indistinct yellow spots on body

Adults:

• Initially reddish-orange markings on a pale background, changing to orange-yellow with some dark spots and yellow lines on the forewings

Three-banded leafhopper
Nymphs

• Two pairs of dark spots on either side of body behind the head

Adults

• Three distinct dark stripes or bands, the first one immediately behind the head  and the additional two on the wings

Virginia creeper leafhopper
Nymphs

• Reddish-brown eyes and a pale yellowish body colour
• Larger nymphs develop a pair of dark reddish-brown spots behind the head and a pair of reddish-orange spots further back on the body

Adults

• Pale yellowish or white with a brown zigzag stripe down each wing, cross veins distinctly red.

Damage for all leafhopper complex species

• pale white or yellowish stippling on the leaves

Often Confused With
Potato leafhopper:  nymphs are bright greenish-yellow; edges of leaves turn yellow and curl downward.

Ozone injury: usually not apparent until mid-August, primarily in hybrid varieties; no nymphs or cast skins on underside of leaves.

Period of Activity
Injury is usually first detected post-bloom.  Second generation nymphs are present after veraison (in mid-August).

Scouting Notes
Monitor for adult activity in early spring with first warm days after leaf tissue is present. Sampling for leafhopper nymphs should be done at 10 days post-bloom, third week in July and again the third to fourth week of August. 

Examine leaves by turning them over slowly to look for leafhoppers on lower leaf surfaces. Bias sampling for first generation nymphs to the lower part of canopy; from July onwards, begin random sampling of leaves from midway on the shoots.  Examine 100 shoots and determine the percentage of shoots that have leafhopper injury and whether it is the basal or upper part of the shoot that is affected.

Leafhoppers prefer vigourously growing vines (for example Vitis vinifera varieties such as Chardonnay) which have few or sparse hairs on leaf under surfaces.  The heaviest populations are normally found on vines at the end of rows or the perimeter of the vineyard. 

Threshold   A rule of thumb commonly followed in Ontario is that treatment is required when 50% of the shoots have obvious signs of injury at the mid-leaf level or above on shoots.  If the vines are under water stress, reduce this threshold to 25% of shoots with injury.

Advanced

Scientific Name

Erythroneura comes (Grape leafhopper), Erythroneura tricincta (Three-banded leafhopper), Erythroneura, ziczac (Virginia creeper leafhopper).

Identification
In all species, adults are 3-3.5 mm long, move quickly and fly when disturbed.  All have 5 nymphal instars that are 2.2-2.5 mm long at maturity, appear similar to adults but do not have wings.

Grape leafhopper
Nymphs:

• Immature stages are pale white
• Lack pigmentation in the eyes
• As nymphs age, spots on back become darker
• Large nymphs have three pairs of pale indistinct yellow spots on body

Adults:

• Initially reddish-orange markings on a pale background, changing to orange-yellow with some dark spots and yellow lines on the forewings

Three-banded leafhopper
Nymphs

• Two pairs of dark spots on either side of body behind the head

Adults

• Three distinct dark stripes or bands, the first one immediately behind the head  and the additional two on the wings

Virginia creeper leafhopper
Nymphs

• reddish-brown eyes and a pale yellowish body colour
• Larger nymphs develop a pair of dark reddish-brown spots behind the head and a pair of reddish-orange spots further back on the body

Adults

• Pale yellowish or white with a brown zigzag stripe down each wing, cross veins distinctly red.

Damage for all leafhopper complex species

• pale white or yellowish stippling on the leaves

Often Confused With
Potato leafhopper:  nymphs are bright greenish-yellow; edges of leaves turn yellow and curl downward.

Ozone injury: usually not apparent until mid-August, primarily in hybrid varieties; no nymphs or cast skins on underside of leaves.

Biology
All species overwinter as adults. As they emerge from "hibernation" they feed on a variety of plants including annual weeds, moving to grapes where they mate and lay eggs on the undersides of fully expanded leaves.  The timing for this varies from one region to another.  First generation eggs hatch in mid- to late June, and the flightless nymphs take 2 to 3 weeks to develop into adults, depending on temperature.  Leafhopper adults and nymphs insert their pointed mouthparts into leaves to suck plant juices. Grape leafhoppers have 1.5 to 2 generations per year while Virginia creeper leafhopper has 2 generations. Three banded leafhopper has a single generation.  Winged adults that appear during July and August lay eggs that develop throughout the fall into overwintering adults.

Period of Activity
Injury is usually first detected post-bloom.  Second generation nymphs are present after veraison (in mid-August).

Scouting Notes
Monitor for adult activity in early spring with first warm days after leaf tissue is present. Sampling for leafhopper nymphs should be done at 10 days post-bloom, third week in July and again the third to fourth week of August. 

Examine leaves by turning them over slowly to look for leafhoppers on lower leaf surfaces. Bias sampling for first generation nymphs to the lower part of canopy; from July onwards, begin random sampling of leaves from midway on the shoots.  Examine 100 shoots and determine the percentage of shoots that have leafhopper injury and whether it is the basal or upper part of the shoot that is affected.

Leafhoppers prefer vigourously growing vines (for example Vitis vinifera varieties such as Chardonnay) which have few or sparse hairs on leaf under surfaces.  The heaviest populations are normally found on vines at the end of rows or the perimeter of the vineyard. 

Threshold   A rule of thumb commonly followed in Ontario is that treatment is required when 50% of the shoots have obvious signs of injury at the mid-leaf level or above on shoots.  If the vines are under water stress, reduce this threshold to 25% of shoots with injury.

Management Notes
Cold and wet weather conditions in spring and fall may suppress leafhopper populations. Fall cultivation and clean-up of adjacent weedy land will eliminate favourable overwintering sites in and near vineyards.
Management with insecticides – Insecticides are used to control the leafhopper complex in most commercial vineyards. SeeOMAFRA Publication 360, Fruit Crop Protection Guide - Chapter 4 Grapes : Recommendations for leafhopper complex at Immediate post-bloom to early fruit set, when threshold is reached.  If Surround is the product of choice, applications should be started as soon as activity is detected and complete coverage of foliage must be maintained.