DEFENDASH - Implications of intraspecific genetic variation and drought stress for the interaction of European ash with two invasive pest species

The objective of this project is to investigate how intraspecific genetic variation in Fraxinus excelsior as well as drought stress and biotic stress might affect the establishment and performance of the invasive insect pest emerald ash borer (EAB). We will (i) conduct an EAB resistance screening by quantifying EAB performance on various F. excelsior genotypes varying in susceptibility to ash die back (ADB), (ii) use untargeted metabolite analyses to study how intraspecific genetic variation and EAB and ADB-caused stress as well as drought stress affect potential direct resistance traits in ash, and (iii) test how intraspecific genetic variability in ash and biotic and abiotic stressors, can affect volatile organic compounds (VOCs) and host finding behavior of EAB and its natural enemies. By potentially identifying ash genotypes with naturally increased defensive traits, our project could contribute to an efficient and sustainable long-term solution to minimize the spread of EAB and to sustain European ash.