Enemy of Vineyard or Grape vines: Phylloxera || Insect/ Pest || Viticulture

Grape Phylloxera

Spots Seen on Grape leaf by the pest

A little, yellowish bug with a 'aphid-like' appearance, Phylloxera (Daktulosphaira vitifoliae), is indigenous to North America. It is regarded as one of the worst grapevine pests in the world and causes significant harm to vines of European ancestry (Vitis vinifera). After several years of infestation, its presence on Vitis vinifera's roots causes the vine to deteriorate, produce less, and eventually die. Replanting Vitis vinifera vines grafted to tolerant or resistant rootstocks is the only way to control the pest once it has taken hold in a vineyard. Phylloxera is only now found in a few locations in Victoria and New South Wales. As most Australian grape plantings are own-rooted Vitis vinifera, which is particularly sensitive to phylloxera, it is crucial to stop the spread of the disease to areas that are now unaffected. There are strict biosecurity control measures in place to prevent spread to other wine regions, with areas classified as Phylloxera Infested Zones (PIZ), Phylloxera Interim Buffer Zones (PIBZ), Phylloxera Risk Zones (PRZ) and Phylloxera Exclusion Zones (PEZ).

Phylloxera Insect

Lifecycle of Phylloxera:

The phylloxera lifecycle involves egg, nymph and adult stages. Adult phylloxera are 1mm long, yellow to brown in colour and predominantly reproduce asexually in Australia. Phylloxera feed on leaves and/or grapevine roots causing death of the European grapevine, Vitis vinifera, within 5-6 years on average, dependent on which endemic strain is present. Phylloxera have been found to survive for up to 29 days without food. Adults can lay around 200 eggs per cycle and are capable of several breeding cycles per season, depending on the virulence of the phylloxera strain, nutrition and environmental conditions. Populations peak between November and March.

How does Phylloxera spread:

Phylloxera can quickly transferred to neighbouring vineyards, grapevines and regions, causing extensive damage, through clothing, footwear, tools, and vehicles (including harvesters), as well as in soil and vine material (leaves and shoots). In nature, crawlers can move from vine to vine by moving along the soil's surface, via the tree canopy, or by moving from root to root underground. They have a potential spread of 25 metres in the wind as well. A vineyard's natural spread is thought to be between 100 and 200 metres every year.

Cure on the vineyard infested by phylloxera insect:

Use of a resistant, or tolerant, rootstock, developed by Charles Valentine Riley in collaboration with J. E. Planchon and promoted by T. V. Munson, involved grafting a Vitis vinifera scion onto the roots of a resistant Vitis aestivalis or other American native species.
Not all rootstocks are equally resistant. Between the 1960s and the 1980s in California, many growers used a rootstock called AxR1.
The use of resistant American rootstock to guard against phylloxera also brought about a debate that remains unsettled to this day: whether self-rooted vines produce better wine than those that are grafted.

Facts that seen on the grape vine that survived Phylloxera insect:

most Chilean wine has remained phylloxera free. It is isolated from the rest of the world by the Atacama Desert to the north, the Pacific Ocean to the west, and the Andes Mountains to the east. Phylloxera has also never been found in several wine-growing regions of Australia, including Tasmania, Western Australia and South Australia.

Another vineyard unaffected by the phylloxera is the Lisini estate in Montalcino in Italy, a half-hectare vineyard of Sangiovese with vines dating back to the mid-1800s. Since 1985, the winery has produced a few bottles of Prefillossero (Italian for "before the phylloxera").

Until 2005, three tiny parcels of ungrafted Pinot noir that escaped phylloxera were used to produce Bollinger Vieilles Vignes Françaises, one of the rarest and most expensive Champagnes available.

It's vital to remember that phylloxera can be quite difficult to entirely remove once it has infected a vineyard. As a result, the use of resistant rootstocks and grapevine varietals is the major strategy for long-term management and prevention of phylloxera damage to vineyards.

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