Definition: Parasite

A living organism that draws the substances it needs from another organism. There are many parasites of the vine: plants (weeds) that compete with the vine by drawing water and nutrients from the soil; animals (birds, small mammals) that feed on grapes; insects that feed on young vegetation or carry bacterial diseases; and cryptogams (fungi) that ravage the plant. The defence against all these pests must be chosen in such a way as to cause as little harm as possible to the environment.