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Green leafhopper
This pest is a small insect of the Empoasca vitis, Empoasca solani, Empoasca decipiens or Jacobiasca lybica species.
Until de 1980s, the green leafhopper would sometimes be found in some vines in southern Portugal; however, it is currently more common and exists in other wine regions in the country.
The green leafhopper is a cicadellidae with 3 to 4 generations per year. Adults spend the winter in sheltered places, which can be trees or shrubs with persistent leaves or infesters. During budding, they move to the grapevine, where they lay eggs near the main rib of the leaves’ lower page or in the petioles. The insect’s toxic saliva is released into the leaves and interrupts the circulation of sap.
Leaves:
- Necroses resulting from the insect’s bites
- Yellow spots in white grape varieties
- Vinous coloration in red grape varieties
- If the attack is too intense, the leaves may drop from August onwards.
Trunk:
- S-shaped trunks with short internodes that remain green for a long period of time. They usually die in winter.
Cultural control:
In winter, when the leafhoppers are on alternative hosts, clean or even remove these plants.
Biological control:
Several insect predators of the green leafhopper are known, but their action is hard to quantify.
Chemical control:
- fenpyroximate
- flufenoxuron
- phosalone
- imidacloprid
- thiamethoxam
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Português