Definition: Nematode

A parasitic worm that attacks the roots of grapevines, causing their destruction. Treatments are not very effective. The best defence is to choose a resistant rootstock. The main class of the nemathelminth order, comprising worms with a digestive tract. Nematodes, or roundworms, form a zoological group that currently includes more than 20,000 species, which may be free-living or parasitic. There are approximately 3,000 species of phytophagous nematodes.