Phylloxera

Reblaus
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The most dangerous of all vine pests (bot. Dactylosphaera vitifolii) is an insect of the order plant lice (Homoptera), subordination Aphids (Aphidina) and the family of dwarf lice (Phylloxeridae). The Phylloxera affects only the Vine , Draws on the leaves or roots and gives off its saliva into the juice cars, which Gall (Growths) causes, which then serve as nesting and feeding. Due to different patterns of behavior over the Vine Different types of suspects. The German biologist Dr. Carl Carl Börner (1880-1953) worked intensively with the insect, and a distinction between a less dangerous and more harmful langrüssligen kurzrüssligen phylloxera. From Erstbefall it takes effect as a result of Nutrients and Root rot usually a maximum of three years for the vine dies off and is completely destroyed. The French scientist Jules Émile Jules Émile Planchon (1823-1888) were in their identification of phylloxera in France in 1868 the aptly named "Phylloxera vastatrix" (devastating louse), which is still used today.

The life cycle in the form of an incessant cycle on the host is very complicated and also strongly affected by the vine species (European or American) dependent. It includes parthenogenetic (parthenogenesis from unfertilized eggs) and sexual generations, with possibly permanent Ortwechsel between shoot and root of the vine. After Befallungsort is therefore in the yellow-green 1.5 mm long Blattgallenlaus (Galli Cola) and the yellow-brown 1.35 mm long Wurzellaus (Radici Cola) differed. The second consists is much more dangerous, since it is the Vascular damaged, resulting in water and nutrient deficiency. The infestation of Leaf other hand, is usually not life threatening. When the vine species (vine species), there are some that both leaf and root knot, root-knot species that no leaf galls, and species which are leaf galls but no root-knot. The group of species is not completely resistant vine leaf or root-knot. Depending phylloxera there going through a complete cycle (leaf and root), or exist on either leaves or roots, and have only a surface or underground, and thus shorter cycle.

In Europe, usually only runs from the multiplication by the root louse, during the full cycle takes place only in America. Only in the above-ground loop resulting offspring with new genetic material, because it exclusively here are males and females. At the root lice, there are only female specimens that reproduce parthenogenetically and lay 600 eggs. Hatched young specimens not immediately attack the roots, but overwinter deep in the ground. In spring, the first young Rebwurzelspitzen punctured and placed the root gall-forming fluid into the tissue. As a defensive reaction to form tissue growths that Nodositäten . For larger infestations, the older, woody roots pierced and as a result Tuberosities formed. These are much more dangerous because they can penetrate much deeper into the root vasculature. Occurring in the young roots Nodositäten lead but also to European varieties not to destroy the infected vines to survive this unscathed. In Central Europe there are four to six generations per year.

The young lice of the last generation (Hiemalen) form the overwintering form. Towards the end of high summer are developing so-called nymphs, are the larvae with wing approaches. This left the ground and evolve to their final molt to winged Rebläusen. This can, of course, spread quickly over long distances. They put small male and large female eggs on the bark of the vine several years, resulting in the trunk free sex animals (Sexuales) slip. This can not take food during their brief and have about eight days of life only the task of copulation. The mated females lay each one into a fertilized winter egg olive bark crevice. This hatch in the spring Maigallenläuse (founder on), which form almost exclusively on American vine species leaf galls and lay up to 1,200 eggs. This hatch after eight to ten days, two types of larvae. Some people are particularly at younger leaves leaf gall again. They reproduce parthenogenetically with six to eight generations per year. The others are born leaf and root lice are looking for vine roots to the soil. There, they complement the underground development cycle, or begin it over again. One wintered phylloxera eggs with 1000 results to fall around 25 trillion descendants!

The rhizomes of some American vines are resistant to phylloxera, because they have adapted over millions of years (see the individual vine species under the keywords starting with "Vitis"). The Resistance results from three factors. The vines react passively to attack the roots, make little or at best, absolutely no Gall and thus avoid the pests, the foundation for an increase. Second, the medullary rays in the roots are well positioned as close to European vines, so that the knots can penetrate only skin deep. And thirdly, forms at the injury caused by the phylloxera feeding site, a protective cork tissue. This prevents the ingress of moisture, Bacteria and Mushrooms That in the non-resistant vines to Root rot and thus leads to complete destruction. Very good but can also American vines be affected by the above-ground pests, but this is not nearly as devastating and causes significant damage only in heavy infestations. Only under favorable climatic conditions European vines of the Blattgallenlaus infected, so it has little significance in Central Europe. Vulnerable to the Blattgallenlaus However, most American vines as well as hybrids .

The phylloxera is native to North America, where it occurs in many areas on the east coast. Here it was in 1854 by the American entomologist Asa Asa Fitch (1809-1879) discovered a year later as "insignificant insect" with the term "pemphigus vitifolius" first described. This seemingly innocuous description was correct, because actually is an occasional pest phylloxera. Only through more vineyards is widely available to an epidemic. This situation, however, was given on the east coast of North America in any way. This could cause the insect no major damage, because the number of Wild Vines limited to one place always was, did not promote an increase in the soil conditions and also many of the more or less resistant American vines to the roots. Unlike other natural disasters that occur without human intervention, the spread of phylloxera was only by massive human intervention in the ecosystem with possible large-scale monocultures. But even that would not have been enough for a worldwide distribution, but secured only by the trade in infected vines.

Shortly before the phylloxera came to England in the 1845 Real Mildew to Europe - the first of four terrible Danaergeschenke from North America. About five to ten years later, the phylloxera, the exact date is of course no longer be determined because the damage was visible until several years later. From the 1850 American vines were in great numbers to England and France as Ornamental Vines and cross purposes, and these go unnoticed, the phylloxera introduced to Europe. This was also done before and gave the vine pest in America since time immemorial, but in the sailing ship times had the pest is a week long trip does not survive, while intact with the fast steam ships rapidly crossed the sea. Around the year 1858 (other sources in 1863) was around at Arles in the Provence vines found an unexplained death and a fungal disease or first frost expected. Last but not least even had God's wrath for the sins of time to serve as a cause. When they dug up the dead vines, it was observed with astonishment that the entire root system had virtually disappeared. Due to the smallness of the insect, it was initially unrecognized. In 1868, a commission with the vineyard owners Gaston Gaston Bazille (1819-1894), the horticultural Félix Sahut and the physicist and botanist Jules Emile Jules Émile Planchon (1823-1888) used, which succeeded in a short time to identify the cause of the mysterious dying vines. However, the origin of the pest from North America remained unclear for some time.

The Phylloxera spread slowly but surely by now in almost every country in Europe almost exclusively on so infested vine material. After Austria-Hungary, they arrived in 1867 (according to other sources until 1872), as the director of the Klosterneuburg Viticulture Institute August-Wilhelm Freiherr von Babo August-Wilhelm (1827-1894) from Germany paid American vines got. In Germany it was first discovered in 1874 near Bonn in the garden Annaberg. But until 1902, the pest came to Wurzburg, 1907 at the river and finally in 1913 after bathing. The other stations were Portugal in 1871, Turkey 1871, Switzerland in 1874, Italy 1875 (South Tyrol until 1901), Spain, Greece in 1878 and 1898th By the beginning of the 20th Century, were destroyed about 75% of all vineyards in Europe. A catastrophe of unimaginable proportions, because wine had great economic importance in Europe, for example, lived in Italy for 80 percent of the population. The material losses were equal to those of the First World War. But also the New World was severely affected, as imported from France and from infected vines by phylloxera arrived in 1873 to California and then in a few years later crippled the burgeoning wine almost straight. And finally, the pest has also been to Australia in 1877 and introduced in 1885 to Algeria, New Zealand and South Africa.

The common danger forced the countries to work together, which was started in 1877 with an "International Conference phylloxera". Between Germany, France, Switzerland, Austria-Hungary and Portugal in 1881 Phylloxera Convention agreed to rules for the import and export of grapes and border controls. The French government was formed in 1870, a commission, whose famous 1885 Chairman Louis Louis Pasteur (1822-1895) was. This was composed of a prize of 20,000 francs, and even later increased to 300,000. In the course of seven years, a total of 700 proposals were submitted (this was tried about half), but the price was never paid. It made Seidenraupenkot treatments, manure and cancer extract, scraping the bark or the planting of defense plants (hemp, valerian). Partial successes have been flooding the vineyards with water and the so-called Kultural process (Soil-injected with carbon disulfide) was achieved. The problem was that even renowned scientists from wrong, and sometimes adventurous assumptions were off and they passionately advocated. The famous entomologist Victor Antoine Signoret (1816-1889) said that grape phylloxera is not the cause but the effect. And the wine known specialist Dr. Jules Jules Guyot (1807-1872) suspected that the cause of sharp pruning .

Even so abstruse, and of course totally ineffective methods such as the Roman wine writers Pliny (23-79) borrowed from burying a dead toad under each vine, the tapping of the vineyard soil, to thereby drive the insect into the sea to the conduction of electricity in the earth and the watering of the vines with white wine were tried. In 1869 Leopold had Laliman Léopold (1817-1897) of Bordeaux recognized that some American vines were immune to phylloxera (but this is attributed to others). At a conference in Beaune, then hit the aforementioned Gaston Bazille before the method, which tops (scions) of European vines on the lower parts (rhizomes) of phylloxera-resistant American vines . graft This was by Gustave Gustave Foex (1844-1906), established in 1868 had already suggested that the phylloxera had come from outside Europe. This was confirmed by Jules Émile then Jules Émile Planchon (1823-1888) through a study tour in America in 1873. He met with the entomologist Charles Valentine Charles Valentine Riley (1843-1895) together, which demonstrated that the insect was identical to the French American. Riley spoke out as one of the first for the grafting onto American rootstock. In the period 1873 to 1876 million have been shipped from documents mainly to France and other European countries, with most of the state Missouri originated.

In practice, however, tolerated many of the American rootstock to European soil is not particularly rare in America in the limestone vineyards. First was the Vitis riparia used as rootstock, which was not suitable for chalky soil. So it was with Vitis berlandieri crossed. Finally, in 1887 by the French Ministry of Agriculture by Dr. Pierre Pierre Viala (1859-1936) led delegation sent to America to make it suitable rootstocks identified. The development took decades and a long time stood in front of two competing camps, "Sulphuristen" who swore to fight with chemistry, and the "Americanists" who preferred to be finished. Finally, translated by latter class, but in the last 100 years, numerous Base and rootstock designed for different requirements. As an important criterion is a high resistance to phylloxera. As Finishing described method was and still is the only solution. But it was very expensive, because at that time there were over ten billion vines in France alone. Therefore, we also tried the issue by Intersection of Americans with European vines or American vines to resolve among themselves and to use as an alternative to the European varieties for wine production. These so-called American or French hybrids , however, were partly insufficiently resistant to the phylloxera, and also the wines often had the unpleasant taste of European Foxton .

Especially during the first success using grafted vines broke the third catastrophe on Europe's vineyards. Because when irony was the story of the rescue of the documents introduced before the second disaster in 1878, the False Mildew introduced from North America. And sadder than the end of the dark century for the wine was then the beginning of the 1880s Black rot imported from America. The longest it took for the phylloxera, and the effective measures were enforced in all countries. To date, few countries are spared, which are Afghanistan , Argentina , Armenia Individual areas in Australia , Chile Individual areas in China , Canary Islands , India , some islands in the Aegean . There are also individual, ungrafted vineyards in other countries such as Germany and Sand wine ). Similarly, the insect can not survive at high altitudes. Individual vineyards ungrafted Vines there are in many countries, including Germany and Austria. But today it is everywhere in general, the usual refinement, it is estimated that this accounts for 85% of all vineyards worldwide. The phylloxera is still not defeated, because in the 1990s in America is a new variant (biotype B) occurred, which has already destroyed many vineyards in California and New Zealand. Big problems caused the early 1960s in California, the recommendation of the University of California (Davis) for the backing AXR 1 , which was too weak phylloxera-resistant. All vineyards had to be cleared again.

For more extensive information related to the phylloxera, in addition to the above-cited references (links), especially in the keywords American vines , European vines , Hybrids , Tuberosities and Base and rootstock included.