These turn-rounds and generally about one millimeter (rarely up to 12 mm) long roundworms (ova, roundworms, trichinae) are among the lower worms. In contrast to more highly developed worms (such as the earthworm) they have no vessels. Usually there are males and egg-laying females, but occasionally also a sexless maiden procreation (Pathenogese). Until sexual maturity, four larval molting will go through. The food intake is through a hollow mouth sting, which moves rhythmically while suckling. They live with numerous species in the soil and also feed on bacteria or mushrooms, which in this case is a positive element in the ecological System of a vineyard soil represents.
It was not until the 1930s that they became the pest of the grapevine recognized, until then one mistakenly suspected the phylloxera, In the vineyards are mainly two species groups that directly by feeding damage and indirectly as a virus transmitter for the Rebstock are very dangerous. As direct damaging parasites, the species cause Meloidogyne, Heterodera and Pratylenchus as a defensive reaction of the vine at the root tips Gallen which they then consume. Although this does not have as serious effects as with phylloxera, but leads to water stress and insufficient supply of nutrients, These root gallbladders occur mainly in sandy soil. The species Longidorus maximus and Rotylenchus borealis pierce the vine roots without bile formation with their mouth sting, suck and destroy them. The shoots remain in the development back, in extreme cases, the vine dies. In terms of frequency, these damages are rather low. The much more devastating effect is indirect, that is, by transfer of virus,
The species Xiphinema index or in German Stilettelchen (occurs only on the grapevine) and Xiphinema vuittenezi transmit the Grapevine fanleaf virus (GFV), the species Xiphinema diversicaudatum the Arabis mosaic virus (ArMV), both the brushwood disease cause. As a preventive defense measure, the use of nematode-resistant vine material is especially important. These are the American species Vitis acerifolia. Vitis champinii. Vitis cinerea and Vitis mustangensis, An earlier usual fight by nematicides however, DBCP (dibromo-chloropropane) is no longer allowed in viticulture.