Tomato / potato psyllid

Bactericera cockerelli

1. Identification

• Common name: Tomato psyllid / Potato psyllid
• Scientific name: Bactericera cockerelli Šulc
• Order: Hemiptera
• Family: Triozidae

2. Pest description

• Small sucking insect, 2–3 mm, greenish-yellow to brownish in colour.
• Adults with transparent wings and an elongated body.
• Flattened, greenish-yellow nymphs, attached to the underside of the leaves.
• They produce honeydew and toxins that cause “psilid yellows” symptoms.
• Insect vector of the bacterium Candidatus Liberibacter solanacearum, the agent of “zebra chip” disease in potato.

3. Main hosts

• Potato.
• Tomato.
• Pepper.
• Eggplant.
• Other cultivated and wild solanaceous plants.

4. Symptoms and damage

• Leaf curling and yellowing.
• Irregular sprouting and reduced growth.
• Abundant honeydew and sooty mould.
• In potato: internal darkening of the tubers (“zebra chip”), loss of quality and commercial unsuitability.
• In tomato: reduced production and deformed fruits.
• High risk of spreading the associated bacterium.

5. Biological cycle

• Several generations per year in warm climates.
• Oviposition on the margin of young leaves.
• Nymphs develop through 5 instars.
• Adults active throughout the year in subtropical regions.
• Populations increase rapidly in spring and summer.

6. Monitoring

• Observation of nymphs and adults on the underside of the leaves.
• Checking for leaf curling and yellowing.
• Monitoring with yellow sticky cards.
• Rigorous inspection in nurseries and imported plant material.
• Immediate notification to the plant health authorities in case of suspicion.

7. Management measures

• Cultural: elimination of alternative host plants and removal of heavily attacked shoots.
• Biological: promotion of natural enemies such as Tamarixia triozae when present.
• Integrated protection: continuous monitoring, interventions only when justified, judicious application of authorised insecticides and compliance with official containment measures.
• Official measures: compliance with DGAV and EU rules for quarantine pests, including restrictions on the movement of plants and plant material.

Bibliographic references

• EPPO Global Database – Bactericera cockerelli.
• CABI Invasive Species Compendium – B. cockerelli.
• DGAV – Plant health fact sheets and alerts on quarantine pests (2019–2024).
• European Commission – Implementing Regulation (EU) 2019/2072 .
• Munyaneza, J. (2012). Zebra chip disease of potato: biology, epidemiology and management.