Spotted wing drosophila

Drosophila suzukii

1. Identification

• Common name: Spotted-wing drosophila
• Scientific name: Drosophila suzukii Matsumura
• Order: Diptera
• Family: Drosophilidae

2. Description of the pest

• Adults: Small flies (≈ 2–3 mm); yellowish-brown body; males with a dark spot at the tip of each wing; females with a serrated ovipositor capable of piercing healthy fruits.
• Larvae: Apodous, white to cream; up to 3–4 mm; develop inside the fruits.
• Eggs: Elongated, whitish; laid under the epidermis of the fruits, with respiratory filaments visible at the surface.

3. Main hosts

• Small fruits: strawberry, raspberry, blackberry, blueberry, currant.
• Prunoideae: cherry, sour cherry, peach, plum, apricot.
• Vine: table grapes and wine grapes.
• Wild fruits and spontaneous hosts that act as reservoirs.
• Preference for fruits with thin epidermis and close to ripening.

4. Symptoms and damage

• Oviposition punctures visible as small depressions or spots.
• Rapid softening of the fruit due to larval development.
• Secondary rots and collapse of the pulp.
• Premature drop of the fruits and total loss of commercial value.
• High economic impact on small fruits and cherry.

5. Biological cycle

• Winter spent mainly as an adult in natural shelters.
• Activity begins in spring and intensifies in summer.
• Females oviposit directly in healthy fruits close to ripening.
• Larvae complete their development inside the fruit.
• Rapid cycle (8–14 days in summer), with numerous annual generations.

6. Monitoring

• Traps with food attractants for early detection and population follow-up.
• Regular counting of captured adults to define risk.
• Direct observation of fruits close to ripening to identify initial punctures.
• Historical record of the farm to forecast critical periods.

7. Management measures

• Cultural: Removal and destruction of attacked fruits; frequent collection of ripe and fallen fruits; elimination of wild hosts; improvement of orchard ventilation; use of insect-proof nets in sensitive crops.
• Biological: Conservation of natural auxiliaries; possible use of entomopathogenic fungi such as Beauveria bassiana under suitable conditions.
• Integrated protection: Intervention based on monitoring with traps; treatments directed at the adults before oviposition; use of selective methods compatible with auxiliaries; integration of frequent harvesting and elimination of infested fruits.

Bibliographic references

• EPPO Global Database – Drosophila suzukii.
• CABI Invasive Species Compendium – Drosophila suzukii.
• Asplen, M. K. et al. (2015). Invasion biology of Drosophila suzukii.
• Walsh, D. B. et al. (2011). Drosophila suzukii biology and management.