1. Phylloxera is a louse which feeds on the roots of grapevines.2. In the late 19th century, Phylloxera destroyed the majority of Europe's vineyards, hitting France especially hard.
3. North American grapevine roots are tolerant of Phylloxera, whereas European roots are not.
4. The best way to evade the ills of Phylloxera is therefore to "graft" North American rootstock onto your vine (i.e. physically stick the roots and the upper part of the vine together).
5. The only countries in the world not to have been affected by Phylloxera are Cyprus and Chile - both of which are geographically isolated (the former is obviously an island and the latter is hemmed in by the Andes, the Pacific and the Atacama desert).
