Context

Research aims and objectives

Produce experimental ash plants

The project will produce many experimental European ash (Fraxinus excelsior) plants from breeding families identified as susceptible (to ash dieback), resistant, or segregating. We will also produce plants from EAB-resistant Asian ash species and EAB-susceptible American ash species.

Experimentally test risk to European ash posed by an invasive beetle related to the emerald ash borer

Agrilus convexicollis is a non-regulated invasive bark boring beetle believed to be a secondary colonist of diseased ash trees, which seems to be already spreading widely in the UK. It is related to emerald ash borer but is thought to be much less destructive to living trees. The project team will test if the larvae of this beetle can colonise healthy ash, working in the Forest Research containment facility.

Investigate the correlation of genetic resistance to ash dieback and to Agrilus beetle species

Working in the Forest Research containment facility, using ash families with different levels of resistance to ash dieback, the team will test whether resistance to ash dieback makes trees more resistant to EAB.

Assess how coinfection influences the development of ash dieback and emerald ash borer damage

The team will inoculate trees with both the ash dieback fungus and EAB larvae within the Forest Research Containment facility. They will test the hypothesis that there is more damage to ash trees when they are attacked by both ash dieback and Agrilus together and determine how co-infection influences development of both the fungus and beetle larvae.

Assess the attractiveness of healthy and diseased ash to Agrilus beetles

Female beetles who are ready to lay their eggs will be exposed to the odours produced by trees with and without ash dieback, to see if there is a preference between the two.

Expected Outcomes

• Development of innovative methods to work with a pest and a pathogen together
• Collection of information resulting in a report on the risk posed to UK ash by Agrilus convexicollis
• Better understanding of the links between resistance to ash dieback and resistance to the emerald ash borer
• Determining how attractive diseased and healthy ash trees are to Agrilus beetles
• The data produced in this project will feed into the UK government’s strategies for breeding ash trees resistant to ash dieback, and for managing the emerald ash borer if it is found in the UK.