GRAPE PHYLLOXERA: WHAT IT IS, ITS HISTORY AND CURRENT SITUATION

The common name for the species is Phylloxera vastatrix. It is a parasitic insect found in four forms; winged, sexual, leaf and root. The leaf form refers to when the insect lives in the leaves. However, the term “root form” refers to when it lives in the roots of the grapevine.

When the parasite lives in the roots of the plant, it feeds on the substances contained within the root through by biting it. This produces cuts on the plant, which is subsequently invaded by fungi and bacteria. This results in the collapse of the plant's root system. Finally, this leads to the decomposition and decay of the root, and therefore the death of the vine.

The parasite multiplies quickly and can spread through the air and on the ground. It also uses tools used by winegrowers as a vehicle to spread from one place to another. In Europe, it is dominant in its root form. It may appear in its sexual form; however, it is not very common, and it almost never appears in its leaf form.

These parasites can reach between 1 and 1.25 mm in length. In 1868, it almost put an end to wine production in Europe, something that we will cover in the next point. Continue reading and don’t miss this compelling story!

Phylloxera arrived in Europe in the mid-19th century through three trading points: Bordeaux, Porto, and Málaga. Its arrival resulted in a crisis for the European wine industry. The first instance of the plague in Spain was recorded in 1878, in Málaga, and once inside it quickly spread throughout the peninsula.

What did this lead to? This meant that a large part of Spanish winegrowers lost almost all of their vines. However, a particular characteristic of its root form means that it cannot grow in sandy soil, as it stops them from creating the tunnels they need to access the roots. Because of this, several plantations were saved, and therefore also several varieties of grape.

As time went by, those involved in the constant fight against the plague came up with a solution. It was in the United States, where phylloxera originated, that a cure was found that would put an end to this threat. It was made by grafting a European vine onto an American vine that was resistant to phylloxera.

In this way, the American vines became the bases from which to graft all European vines, a technique that is still used today. Currently, direct treatments are applied in the winter and spring months as a form of prevention, but it is a controlled plague.

Technology is advancing and giving rise to another type of alternative to combat this plague. An example of this is carbon disulphide or potassium carbonate. However, although it is considered very efficient, it is quite expensive. Another measure that has been adopted is the cultivation of plantations on sandy soils where the insects cannot attack the plant.