Phylloxera Grape Vine Louse

Until the 1860s, the world of wine was growing at a fantastic rate. Wineries were planting record numbers of vines to increase their yields, Australia and the US were beginning to develop their vineyards, and sales were booming. International trade was encouraging the various wineries to exchange vines with each other as they learned about which grapes did best in which areas, and which combinations of grapes produced the most delicious and hearty hybrids.

Then, in 1863, an unwanted passenger was carried from the US into Europe. This was Dactylasphaera vitifoliae, or phylloxera, a small, yellow louse which feeds on the roots of grape vines. Once the winemakers realized their vines were failing, they formed commissions to figure out why. Even when findings were published pointing blame at the louse, winemakers and the public were slow to believe it. They figured it was the weather, overproduction, overpruning, or bad soil.

When France lost almost 75% of its vines, the government began to take the louse seriously. It offered rewards for a solution to this problem. Answered poured in, ranging from the ridiculous to the almost-practical. Flooding the vines and using carbon bisulphide to kill the pests both worked, but both were very difficult to carry out on all vineyards. The answer came in the realization that American rootstock had long since developed a resistance to this louse. The European vines needed to be grafted onto American rootstock.

What is grafting? Grafting is where you take part of one plant, and attach it to part of another plant. In this case the roots of an American vine are attached to the top half of a European vine. The resulting vine is half-American, half-European. This was very hard for the Europeans to swallow. They did not want their wine quality affected by American roots - they felt it would change the flavor of the resulting wine.

It was found that changing out the roots of a vine had little to no effect on the grapes themselves, and as grafting was the only realistic solution to the phylloxera plague, whole vineyards were ripped out and replaced with the American-rootstock-vines. As this was a labor intensive and time consuming process, only the best vines were done first, and vines were replaced with thought and consideration for their quality. As a result, vineyards which were originally overplanted and overproducing now became quality conscious and primed for peak performance. The louse which threatened to destroy winemaking completely in some regions of the world ended up pushing those vineyards into much higher levels of quality, to the benefit of winedrinkers everywhere.

Wine Glossary Main Listing
P Glossary Words

All content on the WineIntro website is personally written by author and wine enthusiast Lisa Shea. WineIntro explores the delicious variety and beautiful history which makes up our world of wine! Lisa loves supporting local wineries and encouraging people to drink whatever they like. We all have different taste buds, and that makes our world wonderful. Always drink responsibly.