Pestipedia

Vineyard Snails

**Vineyard Snails** (e.g., the **Brown Garden Snail** – *Cornu aspersum*) are non-insect, terrestrial mollusks that are significant agricultural pests in viticulture and vegetable farming. The conflict is **direct consumption and contamination**: they feed on the leaves, young shoots, and ripening grapes (or other fruits), causing direct damage. They also leave behind mucus trails and can contaminate harvested grapes and machinery, leading to rejection of the crop lot.

Taxonomy and Classification

Snails belong to the Phylum Mollusca, Class Gastropoda. They are non-insect pests that require high moisture levels to remain active.

Physical Description

Adult snails are 20 mm to 45 mm wide.

  • **Appearance (Key ID):** Soft body protected by a coiled shell; active in cool, moist conditions (night/damp weather).
  • **Damage ID (Key):** Large, irregular holes chewed in leaves or fruit; **silvery mucus trails** left on vines, leaves, or fruit clusters; presence of shells in the crop.
  • **Conflict:** Agricultural, Ornamental, Nuisance.

Distribution and Habitat

Found globally in temperate and Mediterranean climates. Habitat is vines, dense groundcover, leaf litter, and protected areas under vine posts and irrigation equipment.

Behavior and Conflict

The conflict is their size and contamination risk.

  • **Aesthetics:** Contamination of wine grapes with snails, shells, or slime trails is a critical factor leading to commercial rejection.
  • **Survival:** They hide during the day and estivate (become dormant) in dry periods, making them difficult to locate during routine checks.

Management and Prevention

Management is **Physical Exclusion and Chemical Baiting**.

  • **Cultural/Physical Control:**
    • **Sanitation:** Removing groundcover and debris; hand-picking in small areas.
    • **Barriers:** Copper-based barriers that chemically react with the slime, deterring movement.
  • **Chemical Control (Key):**
    • Application of **metaldehyde** or **iron phosphate baits** scattered on the ground near the base of the vines.

    • Conservation and Research

    Research focuses on biological control agents (e.g., predatory snails, birds) and optimizing bait application timing for maximum effectiveness.