Pest categorisation of carrot thin leaf virus.

Area of Science:

• Plant Pathology
• Virology
• Entomology

Background:

• Carrot thin leaf virus (CTLV), a member of the *Potyvirus* genus, has been reported in the EU (Germany, Slovenia, Greece) and internationally (USA, Colombia).
• CTLV affects various Apiaceae species, including cultivated crops like carrots and parsley, as well as wild weed species.
• Aphids (*Myzus persicae*, *Cavariella aegopodii*) are known vectors, widely distributed within the EU, facilitating non-persistent virus transmission.

Purpose of the Study:

• To conduct a pest categorisation of carrot thin leaf virus (CTLV) for the EU territory.
• To assess the risk posed by CTLV to cultivated plants within the EU.
• To determine if CTLV meets the criteria for a potential Union quarantine pest.

Main Methods:

• Review of existing scientific literature and reports on CTLV distribution, hosts, and transmission.
• Analysis of data provided by National Plant Protection Organizations (NPPOs) within the EU.
• Evaluation of potential entry pathways and economic impact.

Main Results:

• Reliable detection methods for CTLV are available, and its identity is well-established.
• CTLV has been reported in Germany, Slovenia, and a single instance in Greece, but has not established widespread presence or official control measures.
• Potential entry pathways include plants for planting and seeds, with cultivated and wild hosts distributed across the EU.

Conclusions:

• CTLV currently does not meet the criteria for a Union quarantine pest due to lack of widespread distribution and official control, though uncertainty remains.
• Economic impact on cultivated Apiaceae crops is possible if CTLV further enters and spreads within the EU.
• Phytosanitary measures can prevent further introduction and spread, highlighting the need for continued monitoring and potential control strategies.