In virtually every country where classic European grapes have been planted, the vines must be grafted to protect them from the inroads of the blight known as Phylloxera.
In 1860, a New World root-eating plant louse (the aphid whose Latin name is phylloxera vastatrix), previously confined to the eastern United States, made its way to Europe where the most widely cultivated species of wine grape, Vitis Vinifera, was grown.
Once established, populations of the tiny root-feeding insect multiplied rapidly in the fields of the defenseless Vinifera grape. In short order, the epidemic swept the continent. By 1868, the damage wrought by Phylloxera Vastatrix – whose species name comes from the Latin word for devastation – had spread to most of the viticultural regions of the European mainland. Within 20 years, more than 2.5 million acres of vineyard had been destroyed in France alone, about 75% of its total crop.
The French government responded by offering a reward of 20,000 francs for the discovery of a practical control method to rescue its teetering wine industry. Soil-based insecticides, flooding of whole fields and other means where tried and abandoned as ineffective. Finally, a commission sent to the United States determined that many wild grape species native to North American were naturally resistant to Phylloxera. Thousands of American cuttings and seeds were transported to France to replace the dying vines. The plants propagated from the immune varieties were used as rootstocks onto which the traditional varieties of vinifera grapes were grafted.
Phylloxera continues to this day to be a scourge. The only known treatment for phylloxera infected vineyards is the destruction of infected vines and replanting with resistant rootstock.
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