Identification of Scaphoideus titanus

Accurate identification is essential to distinguish Scaphoideus titanus from non-vector leafhoppers that may co-exist in the vineyard.

Nymph characteristics (primary control target)

• Appearance: Whitish in early stages (N1-N3), developing ochre or brown spots in later instars (N4-N5).
• Marker: All nymphal stages possess two distinct black spots on the last abdominal segment.
• Behavior: Highly mobile, jump when disturbed and typically found on the underside of basal leaves.

Adult characteristics:

• Size: 56 mm long.
• Color: Brownish-ochre with white and dark markings on the wings and characteristic red-brown transverse bands on the head and thorax.
• Wings: Fully developed, held roof-like over the body.

Not be confused with:

Several other leafhoppers can be present in European grapevines: Empoasca vitis, Erasmoneura vulnerata and Jacobyasca lybica. They have several life cycles per year and show different behaviour and damage. For instance, Empoasca vitis has a greener colour, and crabwalk when disturbed.

Life cycle of Scaphoideus titanus

Scaphoideus titanus is univoltine (one generation per year), which simplifies timing for biocontrol interventions. Understanding the life cycle of Scaphoideus titanus helps optimize control strategies.

• Egg stage (winter): Overwinter as eggs under the bark of two-year-old wood.
• Nymph emergence (May - June): Emerge in spring. Nymphs undergo five instars (N1 to N5) over 21–53 days.
• Adult activity (July - October): Adults appear in late June or July.
• Oviposition (August - October): Females begin laying eggs 12–14 days after emergence, with activity continuing into late autumn.

Damage and disease transmission by Scaphoideus titanus

Understanding the latent period is critical for biocontrol timing.

1. Acquisition: Nymphs acquire the phytoplasma by feeding on the phloem of infected vines.
2. Incubation: The phytoplasma multiplies within the insect (persistent – propagative) before it can be transmitted.
3. Infectious phase: Only nymphs from the 4th instar (N4) onwards and adults are typically capable of spreading the disease.

Note: Targeting N1-N3 nymphs prevents them from ever reaching the infectious stage.

Direct damage:

• Limited impact from feeding
• Minor leaf discoloration

Indirect damage (critical):

• Spread of Flavescence dorée, causing:
  • Yellowing or reddening of leaves (depending on grapevine bunches colours)
  • Leaf curling
  • Poor lignification of shoots
  • Shriveling of grapes
  • Vine decline and death