Three-Banded Leafhopper on Grapes

With about 2500 North American species, it's not surprising that some leafhoppers are agricultural pests. Most species have fairly restricted ranges and plant hosts, although some, such as potato leafhopper are widespread and feed on many plant types. There are three main species that cause damage to grapes (Figure 1): grape leafhopper, potato leafhopper, and three-banded leafhopper. Presence of leafhoppers on grapes does not necessarily warrant applying pesticides; however, no thresholds have been established through research in Ontario.

Figure 1. Three species of leafhoppers commonly found on grape. Left to right: grape
leafhopper, potato leafhopper, and three-banded leafhopper

Three-banded leafhopper (Erythroneura tricincta) has only recently become common in southern Ontario, but can now be found on grapes from southwestern Ontario and Niagara to Prince Edward County. Three-banded leafhoppers are about 3 to 3.5mm long (as are the other species shown in Figure 1) and have three distinct dark stripes or bands across their backs when at rest. The first stripe is behind the head on the insect's thorax and the rear two stripes are on the wings. These distinctive markings make it easy to tell this species from the other common leafhopper pests of grape.

Three-banded leafhoppers, like grape leafhoppers, overwinter in our area as adults. After rousing themselves from "hibernation" they feed on a variety of plants before moving to vineyards when succulent grape leaves are available. Potato leafhoppers arrive by riding strong southerly winds from the southern US. Adult three-banded leafhoppers were active in Niagara by late May this year and have laid eggs in leaf surfaces by now; nymphs should be plentiful by mid to late June. Adult leafhoppers are difficult to catch as they readily fly when disturbed; the trio in Figure 1 were persuaded to pose after being frozen and glued to paper points on pins. Leafhopper nymphs prefer the undersides of leaves but will rapidly scuttle sideways or even backwards when you turn over leaves.

Leafhoppers insert their pointed mouthparts into leaves to suck plant juices, but the damage they cause is different depending on the species. Damage from three-banded leafhopper is much the same as from grape leafhopper (see Figure 2) and is recognized as pale white or yellowish stippling on the leaves. In contrast, potato leafhopper feeding causes yellowing of the leaves, first on the edges and eventually entire leaves, as well as characteristic downward cupping of leaves and shortened shoot internodes.

Figure 2. Stippling on grape leaf caused by grape leafhopper
and three-banded leafhopper. Photo taken in August 2003.