Phylloxera is a very small and pernicious parasite of the leaves and, even more, of the roots of the vine, that came to Europe from America in the end of the past century. Due to this aphid a new viticulture developed, no longer based on the use of ungrafted vitis vinifera, but with double–member individuals in which the root system (rootstock or subject) is resistant to phylloxera (Veronelli).
