Risk assessment for plant pests

Our experts assess for example whether plant pests should be considered for inclusion in the European Union's (EU) list of quarantine pests, requiring specific control and surveillance activities, and to advise on risk mitigation options.

Our assessments support EU legislators in their decisions on measures to protect plant health.

Pest categorisation

Pest categorisation is the first stage of a risk assessment, in which we describe a pest's identity, biology, distribution, regulatory status, host range, and its ability to enter, establish and spread in the EU.

The categorisation also establishes whether the pest meets the criteria to be considered as a quarantine pest (absence or limited presence in the EU but with the ability to enter, establish and spread) or a regulated non-quarantine pest (already present in the EU).

Quantitative risk assessment

If our experts conclude that a pest meets the criteria to be considered a quarantine pest, the European Commission may decide to request us to conduct a quantitative risk assessment, including an evaluation of risk reduction options and current EU control measures.

In our assessments we look at the risk of the introduction and subsequent spread of a new pest, and their impact in the EU. We also compare the consequences of a combination of measures currently in place to reduce the phytosanitary risk.

Priority pests

EU rules require the establishment of a list of pests that could have significant economic, environmental or social consequences, known as priority pests. The list guides EU Member States in preparing measures to control and manage the risks posed by these pests.

The first list of 20 priority pests was established based on an analysis of criteria and indicators carried out by the European Commission's Joint Research Centre (JRC), and risk assessments provided by EFSA.

This list includes pests such as Xylella fastidiosa, the Japanese beetle (Popillia japonica), the Asian long-horned beetle (Anoplophora glabripennis), citrus greening and citrus black spot.

The methodology developed by the JRC and EFSA allows for pests to be assessed quantitatively and ranked according to the severity of the threat they pose.

The results show, for example, that the bacterium Xylella fastidiosa could cost the agricultural sector over €5.5 billion per year in lost production, if it were to spread across the entire EU.

Similarly, if the Asian long-horned beetle were to spread across the EU, the cost to the forestry sector could be as high as €50 billion per year.

EFSA is assessing new potential candidates to join the list of priority pests. We are working together with the JRC and expect to publish our assessments by the end of 2024.

Commodity risk assessment

As required by the EU’s plant health law, the European Commission drew up a list of high-risk plants, i.e. plants that pose a pest risk of unacceptable level for the Union territory, that are banned from introduction into the EU.

Our experts assess the threats posed by the plants on this list to support the European Commission in deciding whether to update the list. 

Before starting this work in 2019, we published a report outlining the information third countries need to provide when challenging the validity of EU import restrictions on a plant or plant product. 

We also produced guidance explaining the methodology we use when carrying out these assessments.

An infographic is also available to visually illustrate how the EU makes sure that imported plants are safe.

Our experts also assess the risk that plant pests pose to a specific commodity imported into the EU, or the efficacy of measures taken by an exporting country to prevent or reduce the risk to plant health in the EU.