Pest categorisation of Little cherry pathogen (non-EU isolates)

Area of Science:

• Plant Pathology
• Virology
• Entomology

Background:

• Little Cherry Pathogen (LCP) comprises two distinct viruses: Little Cherry Virus 1 (LChV1) and Little Cherry Virus 2 (LChV2), collectively known as LChV.
• LChV is transmitted through vegetative propagation and, for LChV2, by mealybug vectors.
• While LChV is present in various countries, including within the EU, non-EU isolates are not currently known to occur in the EU.

Purpose of the Study:

• To conduct a pest categorisation of non-EU isolates of LChV for the European Union (EU).
• To evaluate whether non-EU LChV isolates meet the criteria for being a Union regulated non-quarantine pest or a Union quarantine pest.

Main Methods:

• Review of available scientific literature and data on LChV biology, epidemiology, and host range.
• Assessment of LChV non-EU isolates against criteria defined for pest categorisation by the European Food Safety Authority (EFSA).
• Analysis of transmission routes, vector presence (Phenacoccus aceris), and potential for establishment and spread within the EU.

Main Results:

• Non-EU LChV isolates are restricted to Prunus species, primarily cherries.
• LChV non-EU isolates are expected to enter, establish, and spread within the EU via plants for planting and vectors.
• Non-EU LChV isolates meet all EFSA-evaluated criteria to qualify as Union quarantine pests.

Conclusions:

• Despite meeting quarantine pest criteria, the impact of non-EU LChV isolates may be limited, similar to existing EU isolates.
• Key knowledge gaps include differences between EU and non-EU isolates, vector efficiency in the EU, and symptom severity on EU cherry varieties.
• Further research is needed to address uncertainties regarding the epidemiology and impact of LChV non-EU isolates under EU conditions.