The news: Scientists emphasise that integrating social, economic and institutional dimensions is key to managing outbreaks in Europe
Xylella fastidiosa outbreaks in Europe have sparked backlash among farmers and the general population, raising questions about the social, economic, and cultural impacts of alien plant pathogens in a new territory. The EU-funded BeXyl – Beyond Xylella project involved social scientists and economists to research the socio-economic dimensions, focusing on institutions’ coordination, stakeholders’ experiences of disease threats, and attitudes towards Integrated Pest Management (IPM) strategies.
Outbreak management approaches
BeXyl researchers analysed the strengths and weaknesses of EU and national strategies for Xylella fastidiosa outbreak response. A common methodology to assure comparability across countries was defined to assess audit reports across key affected countries, including Italy, Spain and Portugal, with the objective of establishing benchmarks to improve coordination and effectiveness of response measures.
The methodology combines qualitative information from Expert Working Groups (EWG), composed of scientists and phytosanitary authorities, and quantitative analysis of the role of information and misinformation in outbreak management.
Stakeholder knowledge, perceptions and IPM uptake
BeXyl’s social scientists sought to better understand knowledge levels, experiences and attitudes towards Xylella fastidiosa as a threat to important food crops, and the acceptability of different IPM strategies as potential solutions. This was done using a case study approach involving semi-structured interviews and focus groups with a wide variety of affected stakeholders (e.g., farmers, agronomists, cooperative managers) and other key actors (N=146) in three locations across Spain and Italy.
Findings reveal strong context dependence in how risk is perceived, how control strategies are evaluated, and where trust is placed. Participants in Córdoba (Spain) where Xf is currently not present reported low perceived vulnerability to and limited knowledge of Xylella. In Alicante (Spain), participants showed high concern, frustration with eradication policies, and uncertainty about how to move on from the disease. After a decade of impact, participants in Salento (Italy) appeared to be moving towards pragmatic adaptation, with interest in resistant varieties, diversification, and preparedness for long term management.
Across all regions, stakeholders favored prevention and monitoring measures but raised concerns about feasibility, cost, technological complexity, and governance. Insights highlight the need for region specific, socially informed IPM design and underscore the importance of integrating behavioural and socio-political factors into vector borne plant disease preparedness frameworks.
Ecological impacts: soil, biodiversity and habitats
The research provides new insights into the ecological impacts of Xylella fastidiosa infection and related disease management measures. Researchers highlighted that eradication practices may have a detrimental impact on soil and arthropod communities, emphasizing the need of integrating sustainable environmental conservation practices.
Socioeconomic analysis and IPM adoption scenarios
BeXyl’s economists simulated the impacts of Xylella fastidiosa expansion on crops that are potentially susceptible to being affected by the bacteria (olives, grapevines and citrus) using a regional agroeconomic model. Two scenarios were considered and compared with a baseline situation in which integrated pest management (IPM) was not implemented. In the first scenario, a moderate IPM program was simulated, while the second scenario considered a more restrictive IPM approach. Although more restrictive IPM programs lead to lower production losses, implementation costs increase because greater changes to current production methods are required.
Results showed that without additional IPM measures Xylella fastidiosa could lead to severe production losses in production reaching a maximum of 55% in the case of olives. Reductions in production would translate into higher prices, with a maximum impact of 6% for the case of citrus. The impacts can be partly offset by implementing the most stringent IPM program. In such a scenario production of olives would only be reduced by 14% and price increases for citrus would be a mere 1%. Implementing these IPM programs would not significantly reduce the profitability of growing these crops.
This aggregated approach is complemented with primary data collection from farmers using surveys to elicit their preferences for IPM in Italy and Spain, and acceptance for early detection technologies developed by the project. The analysis of farmers’ responses will allow researchers to estimate the level of subsidies needed to encourage the adoption of different IPM programs and to assess the potential for implementing surveillance and eradication programs based on detection using these new technologies.
Finally, researchers also surveyed more than 2,000 citizens in Italy and Spain to understand their preferences regarding the restoration of areas affected by Xylella fastidiosa. The survey examined different levels of crop management intensity, types of control measures, and the governance levels at which restoration programs are managed. By combining the results of the farmer and citizen surveys, BeXyl will be able to support decision-makers in identifying measures that maximize social welfare.
Towards more inclusive and sustainable IPM strategies
Effective management of Xylella fastidiosa requires an integrated approach that goes beyond biological aspects, incorporating social, economic and institutional dimensions.
The results of the BeXyl project will contribute to improving the policies and decision-support tools, fostering the adoption of sustainable and context-adapted IPM strategies, and strengthening the resilience of European agricultural systems against the pathogen.
Xylella fastidiosa
Xylella fastidiosa is one of the most threatening plant pathogens worldwide, capable of colonising more than 700 plant species. It causes diseases responsible for agricultural and environmental losses amounting to millions of dollars in the United States and Brazil. In October 2013, the bacterium was detected for the first time in the EU, on olive trees in the Apulia region of southern Italy. Since then, outbreaks have also been reported in France, Spain and Portugal.