Also known by the fancy latin name Empoasca lybica or Empoasca vitis, this is a small green insect from the grasshopper family that some years causes stress to us in the vineyards during the final part of the harvest.
The insect sucks the sap from the leaves of the vines and thus attacks the plants nervous system so the leaves dry out and curl. In worst case the plant stops generating energy and ripening its grapes. So, sometimes it's a matter of waiting long enough for the fruit to ripen sufficiently, but not long enough for the insect to shut down the plant totally.
There’s no efficient way to spray against this small beast, so it's all about timing the picking and also hoping for a bit of goodwill from Mother Nature