Phylloxera , the little bug that came from the United States and almost wiped out European viticulture. Fortunately the solution was found and today all plants are put on resistant rootstocks.
1- What is vine phylloxera? Phylloxera vastatrix . Definition and meaning.
Its origin is in the United States, where it feeds on the leaves and roots of the American vine.
The phylloxera of the vine is the most fearsome enemy of the vine. It is an aphid (Phylloxera vastatrix) whose only known host is the vine.
The phylloxera plague in vine is found in the forms “gallícola”, “radicícola” and “winged and sexual” .
In its root forms it lives and feeds on the substances contained in the root through its bites, being soon the cause of root rot and the death of the plant .
2- A little history about phylloxera:
Phylloxera in Europe and France:
Phylloxera arrived in Europe in 1868. The entry points are through commercial ports such as Bourdeaux, Oporto and Malaga.
Phylloxera in Spain:
We have the first record on phylloxera in 1878, in Malaga.
In the image we can see the different points through which the phylloxera entered and spread throughout the peninsula.
The main focuses are, Porto, Malaga, Denia and Navarra and Catalonia due to the influence of France.
In its wake, it wiped out practically all European vines.
It did not fully colonize the territory, since the rootless form does not develop in sandy soils and it was thanks to this that many varieties could be recovered to graft them on resistant American vines.
The solution was found (in the same place where the plague came from) by grafting the European vine (sensitive) on an American vine resistant to phylloxera.
In this way, the total extinction of the European varieties that we know today was avoided . For this reason, since the end of the 19th century, American species (American vines) have been used as rootstock for Vitis vinifera.
3- What are the symptoms and consequences of phylloxera?
The insect is spread by the winged forms , which are blown by the wind over long distances and from one vineyard to another.
The attacks of the insect on the root of the plant are characterized by bulges in the form of knots or tuberosities and of a certain thickness, which interrupt the sap currents.
In its chicken form, the attack is manifested on the upper face of the leaves by a kind of bulge or gall caused as a cause of the laying of the insect, which is usually extraordinary.
In the first year of the insect attack, its effects are almost imperceptible.
In the following year in which the shoots are cut, the leaves lose their freshness and chlorophyll disappears at their edges, taking on a yellowish hue.
The fruits fall before maturity due to root rot, and the plant dies .
4- What would be the protection or treatment strategy against Vine Phylloxera?
The only control is the planting of resistant rootstocks.
The control of phylloxera in current viticulture is based on the grafting of European varieties on resistant rootstocks .
The Riparia, the Rupestris, the Berlandieri, pure or hybrid, offer a great guarantee.
Sometimes a direct fight in the aerial part of the plant is necessary, by means of winter / spring treatments at the time of the appearance of the galls of the first generation.