The infamous insect, first described in the 1850s and which ravaged almost all European vineyards, has had only marginal importance since the vineyards were replanted. Although phylloxera appears to be under control today, the danger of the pest reappearing remains a current concern.
In the early 1980s, Californian vineyards suffered violent phylloxera attacks in the famous Napa and Sonoma valleys. Ironically, it was from California that the aphid launched its bomb of mass destruction!
In 2006, the Yarra Valley vineyards in the Australian state of Victoria were attacked by the insect. The aphid's assault now seems to have been defeated, but producers must remain vigilant as many vines are planted on their own roots—that is, without rootstock.
In Switzerland, a case was observed in 1987 in the Tessin on Merlot with the discovery of several founding galls.
And in Valais? The era of "Versannes"—the practice of digging deep trenches to bury old vines and grow new ones—is long gone. The devastating louse forced Valais winemakers, like those everywhere else in the world, to use rootstocks. Scrupulous and conscientious, Valais winemakers quickly adapted to this new reality. Today, they are more concerned with attacks of powdery mildew or downy mildew, which were the first diseases to affect Valais vines.
The Agroscope research station remains attentive to the problem and works in close collaboration with cantonal viticulture services.
