Phylloxera, or grape phylloxera, is a devastating vineyard disease caused by the tiny insect Daktulosphaira vitifoliae. These minuscule yet menacing agents of destruction are aphids and belong to the family Phylloxeridae. Despite phylloxera’s tiny size, it remains a monumental part of wine and viticulture. It feeds on the roots of grapevines, causing significant damage to the plant’s vascular system, ultimately leading to the vine’s decline and death.
In this clip from Sommeliers Notebook: An Intro to Phylloxera, available exclusively on SOMM TV, Jonah Beer explains how the louse attacks and prevents root vines from taking up nutrients.
Wine’s Phylloxera History
Phylloxera originated in North America, where native grape species coevolved with the insect and developed natural resistance. However, when European settlers introduced American grapevines to Europe in the 19th century, they unknowingly brought the pest with them. European grapevines proved highly vulnerable, with no natural defenses against this pest.
The disease quickly spread throughout Europe, initially affecting wine-producing regions in France and then moving to nearby Italy, Spain, and Germany. Many vineyards were devastated, and wine production came to a near standstill in some areas. With the loss of countless vineyards, wine production plummeted in Europe. Many vineyard owners faced financial ruin, and the livelihoods of thousands of people were at stake.
Following several years of devastation, vintners, scholars, and visionaries united in a desperate struggle to salvage their wine heritage. Eventually, rootstocks resistant to the disease were identified, leading to a new era of vineyard management.
The use of resistant rootstocks was a significant breakthrough allowing vineyards to recover and rebuild. Over time, new methods of controlling and preventing infestations were developed, including chemical treatments and improved vineyard management practices.
It reshaped the entire wine industry, influencing vineyard practices, grapevine selection, and winemaking techniques.
What Are the Symptoms of Phylloxera?
Identifying a phylloxera infestation can be challenging due to the insect’s small size, but there are specific symptoms to watch out for. Infected grapevines may display wilting leaves, stunted growth, yellowing foliage, and an overall decline in health.
How Is It Transmitted?
Phylloxera transmits through the movement of infested plant material, such as rooted cuttings, rootstocks, or grapevine equipment. The insects can also crawl through the soil, infecting new locations. The ease with which it transmits played a significant role in its rapid global spread and the devastating consequences it brought to vineyards worldwide.
How Is It Prevented?
One of the most effective ways to prevent and manage phylloxera infestations is the use of resistant rootstocks. Some American grape species, such as Vitis riparia and Vitis rupestris, naturally resist the pest. By grafting European grape varieties like Cabernet Sauvignon, Merlot, and Chardonnay onto these resistant rootstocks, vineyards can protect their crops from the devastating effects of the pest.
Which Countries Are Phylloxera Free?
Australia and Chile have managed to evade the destructive louse, earning a distinguished place among the few phylloxera-free winemaking countries.
With its geographic isolation across a vast expanse, Australia has proven to be a formidable fortress against the encroaching aphid. Adherence to strict quarantine measures and the utilization of resistant rootstocks have fortified Australian vineyards, safeguarding their vines. Meanwhile, Chile’s unique geography next to the Andes and well-regulated vineyard management has woven a protective shield around its vines.
Although phylloxera is still a threat, the wine industry has largely recovered thanks to the use of resistant rootstocks and other control methods. However, the memory of nearly destroying an entire industry serves as a reminder of the importance of vigilance and the constant pursuit of knowledge in viticulture and vineyard management.