Of the many natural enemies of the vine, one is the most destructive. It is a parasitical insect, the root-burrowing plant louse, phylloxera vasatrix. Many varieties of grape vines are fatally susceptible to its attack.
Although phylloxera apparently has always lived in the eastern United States, native American vines like Concord, Catawba, and Delaware have endured the parasites poison saliva. Due to their heavy rootstock, it seems these vines have developed immunity to the bug.
European grape varieties belong to a different species, “vitis vinifera”. Chardonnay, Cabernet, Pinot Noir and all the other familiar wine-grape types (from which all the world’s best wines are made), are classified as “vinifera”.
During the latter half of the 1900s, phylloxera accidentally got shipped to Europe. It arrived there inadvertently on some native American vine cuttings which were being sent to English and French botanical gardens for experimental purposes. First recorded abroad in 1863 in Kew, near London, the pestilent insect soon spread to nearly every continental and island vineyard in the world.
Vinifera, with no immunity to the invader, rapidly succumbed. Within two decades phylloxera had destroyed virtually all the vineyards in France, about 2 1/2 million acres. It managed to wipe out at least as many, additionally, in other countries. The destruction of these vineyards between 1870 and 1900 stands unparalleled in agricultural history.
WOMC Newsletter readers may recall our discussion of Bordeaux winemakers who settled in’ Spain’s Rioja district during the late 1880s, bringing with them their French oenological techniques. Their migration was specifically spurred by the advances of this intruder. Luckily for them by the time the insect had made its way across the Pyrenees into Spain (where it succeeded in devastating most of the vineyards before 1910), two Frenchmen had worked out a solution to the scourge. Gaston Bazille, a landowner, and Jules Planchon, a botanist and professor of pharmacy, found that they could successfully graft European vines onto phylloxera-resistant American rootstocks. Though tedious, this proved to be a feasible remedy.
Thousands of American cuttings were sent to France. The French selected the best of these and distributed them throughout the world for grafting. When the insect laid waste California’s vineyards in the 1880s, the native U.S. rootstocks now in general use here, came to us, ironically, from France.
Today, due to local geophysical conditions adverse to the insect’s survival, a few districts are phylloxera free. In Washington State, Temecula, and Chile, grape vines currently thrive, ungrafted, on their own rootstocks.