Pest categorisation of Sirex nitobei

Area of Science:

• Entomology and Plant Pathology
• Pest Risk Analysis
• Forestry and Agriculture

Background:

• Sirex nitobei (nitobe horntail) is a woodwasp native to East Asia, known to attack various pine species.
• It was identified as a potential regulated pest during a risk assessment of artificially dwarfed Pinus thunbergii plants from Japan.
• Currently, S. nitobei is not listed as a Union quarantine pest in the EU but poses a potential threat.

Purpose of the Study:

• To perform a pest categorization of Sirex nitobei for the European Union territory.
• To assess the criteria for S. nitobei to be considered a potential Union quarantine pest.
• To evaluate the risk of introduction, establishment, and potential damage to pine species within the EU.

Main Methods:

• Pest categorization based on existing scientific literature and regulatory frameworks.
• Analysis of S. nitobei's biology, lifecycle, host range, and geographical distribution.
• Assessment of potential introduction pathways, including trade of plants and wood products.
• Evaluation of climatic suitability and host plant availability in EU member states.
• Review of existing phytosanitary measures and potential for biological control.

Main Results:

• Sirex nitobei is present in Japan, the Republic of Korea, and parts of China, attacking several Pinus species.
• The pest's lifecycle is one year, and it causes tree death through a symbiotic fungus and phytotoxic mucus.
• A potential pathway for introduction exists via artificially dwarfed Pinus thunbergii plants from Japan, despite general import prohibitions.
• Climatic conditions and host availability in parts of the EU are conducive for S. nitobei establishment.
• The pest is potentially damaging to pines, but phytosanitary measures and biological control options exist.

Conclusions:

• Sirex nitobei meets all criteria to be regarded as a potential Union quarantine pest.
• The risk of introduction via specific trade pathways warrants strict phytosanitary surveillance and control measures.
• Preventative actions are crucial to protect EU pine resources from the potential damage caused by this invasive species.