Grape leafhopper

The grape leafhopper (Erythroneura comes) is a significant insect pest belonging to the order Hemiptera and the Cicadellidae family. These tiny insects cause economic damage to viticulture by piercing plant tissues and extracting sap, which deprives the vine of essential nutrients.

The primary host for this species is the grapevine. While it is most commonly associated with commercial vineyards, it can also inhabit wild grape species. Its presence is often underestimated until significant foliage discoloration becomes visible across the vineyard rows.

The biological cycle of the grape leafhopper involves overwintering as adults in leaf litter or under loose bark. In the spring, they migrate to the emerging foliage to lay eggs. The nymphs (immature stages) stay on the underside of leaves, feeding and molting until they reach the adult stage, typically completing multiple generations per year.

Symptoms of infestation include the appearance of small, white stippled spots on the leaves. As feeding continues, these spots merge, leading to a bleached appearance, leaf necrosis, and premature defoliation.

• Reduced photosynthesis rate
• Poor berry development
• Lower sugar concentration in harvested grapes
• General decline in vine vigor

Effective management requires a combination of sanitation and chemical interventions. Cultural practices like removing debris and leaf litter help reduce overwintering sites. When populations reach economic thresholds, the application of targeted insecticides, often timed to coincide with the presence of nymphs, is recommended to minimize impact on the crop.