A pest is any organism that reduces the availability, quality or value of a human resource. Most organisms in vineyards are non-pests, some can be occasional (or potential) pests, but the main problems are the key pests, which cause significant damage every season unless some management action is taken. Many key pests are parasites where the host/parasite relationship has become unbalanced.

There are different philosophies for managing pests:

• Prophylactic or prescriptive
• Reasoned pest control
• Integrated Pest Management (part of integrated viticulture)