Not just phylloxera but the various fungi species that create powdery and downy mildew, among other illnesses for which Vitis vinifera has no natural resistance. And therefore Europeans must now spray fungicides at a level they never had to before.

North America is the centre of diversity and likely origin of the vitis genus, and so has evolved pest resistance that the isolated Eurasian vitis vinifera/sylvestris has not.