Chaîne Online News

Actualités en ligne / News On-Line

The Chloé Grandpierre Column no3


Do you know about this little bug? This destructive aphid not only destroyed the Bordeaux vineyards but devastated vines throughout Europe during the 19th century. Well, yes, you guessed ... I'm talking about Phylloxera.

“A neighbour is a pest quite close to a human being” - Pierre Desproges

Everything began with the curiosity of some botanists who enjoyed free-trade. They brought back new plants from the USA and gradually a strange disease was discovered in greenhouses which destroyed vine pot plants.

The first infection was declared in 1863 in the Gard Region (South-East France) and spread like an oil slick in France: 1865 - Bouches-du-Rhône, 1866 - Floirac in the Gironde, 1876 - Orleans (100km south of Paris), 1894 – Champagne.

This disease respected no borders and ravaged its way throughout Europe and the rest of the world: 1863 - London, 1865 - Douro Valley of Portugal, 1871 - Switzerland, 1874 - Bonn, Germany, 1875 - Austria and Australia, 1879 - Italy near Como, 1880 - South Africa, 1885 - Algeria, 1888 - Peru. It was a full-scale invasion with attacks on all fronts!

You may say all that information is very interesting but what exactly is Phylloxera? And more importantly what are the consequences of this invasion?

Photos (c) Chloé Grandpierre

There are two types of Phylloxera: one which is in the roots and will kill the vine. The second is the gall Phylloxera which affects the leaves but which is not fatal. The main consequence of this aphid is the death of a vine within three years of being infected. This is certainly what happened in Bordeaux. This famous vineyard area was destroyed because there was no known means at the time to beat this little bug!

Left: Phylloxera attacking the roots of a vine   /   Right: Gall Phylloxera on the leaves

Photos (c) Prof. Dr. Joachim Schmid, Department of Grapevine Breeding and Grafting, Geisenheim Research Institute, Germany

In 1868 Jules Emile Planchon accurately described the aphid and named it Rhizaphis Vastatrix. He was unaware that in the USA, this aphid was already well-known. Planchon sent some samples to Dr Signoret, a Parisian entomologist. Signoret placed the aphid in the Phylloxera family. Coming from the east coast of USA, Europe and Bordeaux needed more than 30 years to fight against the invasion of this little bug.

Historically it was a serious wine crisis. Phylloxera wasn’t the only problem. Added to the little bug there was mildew (brown rot), oïdium (powdery mildew) as well as a cryptogamic disease. (Editor’s note: A cryptogam is a plant, in the wide sense of the word, which reproduces by spores)

Phylloxera has an annual reproduction cycle: males and females mate during the summer months. Only one egg is laid on the stump which is the 'winter egg'. This egg, which is always a female aphid, hatches at the beginning of Spring. This female either goes down into the roots (a root Phylloxera) or goes up to the leaves and becomes a gall Phylloxera.

Right : Phylloxera and its eggs
Photo (c) Prof. Dr. Joachim Schmid, Department of Grapevine Breeding and Grafting, Geisenheim Research Institute, Germany

But the cycle is not over: these females will hatch out again as soon as they are adults, 40 to 100 eggs without mating and all are female! During summer the females will shed to nymph: the winged Phylloxera hatch eggs again this time both females and males which live long enough to reproduce and hatch out the 'winter egg' and so the cycle continues ad infinitum. With this information we can understand how Phylloxera spread so fast.

What was done to fight against Phylloxera in Bordeaux?

Wine-growers have a lot of imagination and the Bordeaux wine-growers being no exception pooled all their ingenuity and knowledge to trial many treatments in order to destroy Phylloxera.

Their experiments included mustard gas, applications of a mix of lime, naphthalene and water on the vines to kill the 'winter egg', injecting the volatile liquid carbon bi-sulphide into the earth and because Phylloxera hates humidity vineyards were flooded with water. This last approach was efficient but the low-lying areas of Bordeaux are not where the well-known Chateaux are located. As you will gather, there were a lot of ideas but no demonstrable results.

Eventually the solution came naturally. It involved going back to the roots as it was realised that in the USA the vines were not attacked by Phylloxera. Was the solution in the vine?

Indeed it was, so wine-growers had to grow non vitis vinifera (which means non-European vines) in order to contain the epidemic. In fact this was the solution which was adopted in Bordeaux. Non vitis vines were planted and the vitis ones were burnt. Despite this approach a new problem appeared. The non vitis were not giving the same quality of wines as the vitis. Before arriving back at producing a top quality product, wine-growers had to wait another 30 years and experimentation with many hybrids and grafts.

Left: Swollen nodules and secondary fungal growth on vine roots caused by Phylloxera   /   Right: Root Phylloxera

Photos (c) Prof. Dr. Joachim Schmid, Department of Grapevine Breeding and Grafting, Geisenheim Research Institute, Germany

It is rare in France to come across vines older than the period of devastation caused by Phylloxera. However, at Sarragachies, a town in the Gers département at the heart of the St Mont appellation, there is plot which is 200 years old. In 2012 it was designated as a 'Historic Monument of France' - the first vines to have this title. Furthermore, Maison Bollinger in Champagne has a plot of Pinot Noir with original ungrafted rootstock.

Although still present, Phylloxera is no longer ‘Enemy No 1’ in French vineyards. It has been overcome by the use of rootstocks resistant to Phylloxera. However, the guard cannot be dropped as in the 1990’s this little bug caused a lot of damage in California.

Chloé Grandpierre
Oenologist   /   Professionnel du Vin, Bailliage of France

A German chart showing the annual reproduction cycle of Phylloxera