Name (also Blattgallenlaus, lat. Gallicola) for the above-ground on leaves of the Rebstocks occurring phylloxera; see there the complex life cycle.
This most dangerous of all Rebschädlinge (bot. Dactylosphaera vitifolii) is an insect of the order plant lice (Homoptera), suborder aphids (Aphidina) and family of dwarf lice (Phylloxeridae). The phylloxera attacks exclusively the grapevine, sucks on the leaves and / or the roots, releasing their saliva into the juice paths, which Gallen (Growths), which then serve as oviposition and food. Due to different behavior patterns compared to the Rebstock Different types are suspected. The German biologist dr. Carl Börner (1880-1953) distinguished between a less dangerous langrüssligen and a harmful kurzrüssligen phylloxera. From the first infestation it lasts by following effects like nutrient deficiency and root rot usually a maximum of three years, until the vine dies and is completely destroyed. The French scientist Jules Émile Planchon (1823-1888) gave the phylloxera in their identification in France in 1868 the aptly named "Phylloxera vastatrix" (devastating louse).
The life cycle is strongly affected by the vine species, namely Europäerrebe or Amerikanerrebe dependent. It takes place either in the form of a complete cycle or continuous cycle between vine (above ground) and root (underground) or only on leaves (only above ground) or only roots (only underground) and thus shortened cycle. There are parthenogenetic (Virgin production from unfertilized egg cells) and sexual generations. According to the site of infestation, a distinction is made between the yellow-green 1.5 mm leaf reed (Gallicola = leaf gall louse) and the yellow-brown 1.35 mm root burge (Radicicola = root louse). The second is much more dangerous because it is the Xylem damages, leading to water and nutrient deficiencies. The infestation of leaves is usually not life threatening. In the vine species, there are some that form both leaf and root galls, the root gall, however, no galls, and the leaf gall, but not root galls. The group of perfect resistant Vine species forms neither leaf nor root galls.
In Europe, only the propagation through the root lice usually proceeds, while the full cycle takes place only in America. Only in the aboveground cycle offspring with new genome, as there are only males and females. In the root lice, there are only females that reproduce parthenogenetically and lay 600 eggs. Young hatchlings do not immediately attack the roots, but hibernate deep in the soil. In the spring, the roots are pierced with the trunk (half the length of the body) and the saliva is introduced into the tissue. As almost panic defense reaction of the vine to form nodular thickening growths. These lice feed on the lice, they absorb them. The pest can only live through the bile, because the hard roots themselves could not be directly gnawed.
In Central Europe, there are four to six phylloxera generations per year. The young lice of the last generation (Hiemalen) form the hibernation form. Towards the end of summer, nymphs develop, larvae with wings. These leave the soil and develop after their last moulting to winged phylloxera (Sexuparae). The ability to fly, they can spread even over long distances quickly in other vineyards. They lay small male and large female eggs on the perennial bark of the vine, from which the sexless sex animals hatch. These can not absorb food and have only the task of copulation during their only eight-day life.
The mated females lay a single fertilized olive-green wintering in a bark rind. In the spring, it grows the Maigallenläuse, which only in American vines species (Vitis vinifera is resistant to the leaves) form bile and lay up to 1,200 eggs. This will give birth to two larvae after eight to ten days. Some of them, especially on younger leaves, re-create leaf galls. They multiply parthenogenetically with six to eight generations per year. The others are leaf-born root lice and seek out the vine roots in the soil. There they complete the subterranean development cycle or start it anew. An overwintered phylloxera with 1,000 eggs yields around 25 trillion offspring by the autumn. The enormously complex cycle or life cycle of leaf blue shrubs and root shrubs is shown in the graph:
There is a distinction between two types of roots and thus different effects of the infestation. With less infestation, the young, un-wooded root tips are first pierced. The resulting root galls are called Nodositäten, They occur not only in the European, but also in most American vine species, but are relatively harmless and do not lead to annihilation. With larger infestation but also the older, woody roots are pierced and as a result the tuberosities educated. These are much more dangerous because they can penetrate much deeper into the vascular system of the roots. Certain American vine species are immune to both, the most resistant...