Estimating potential yield and economic losses caused by an emergent quarantine pest using farmer surveys and temperature-driven risk modeling: the case of the potato psyllid (Bactericera cockerelli) in Peru.

Emerging and quarantine pests threaten crops and food security, particularly in low-income countries, where data on past damage are scarce. In these settings, rapid estimates of potential yield and economic losses are essential for informing pest management and policy, often relying on alternative data and modeling approaches. Following the recent emergence of potato psyllids in Peru, this study developed an integrative framework to estimate potential losses. The approach combines (i) farmer-reported yield losses and management practices from 109 potato farmers in northern Peru, (ii) temperature-based modeling to identify climatically suitable areas for pest establishment, and (iii) regional potato production statistics to assess the national exposure. Approximately 37% of Peru's potato-growing areas were classified as having a high climatic risk. Integrating these areas with farmer reports yielded an estimated national loss of 18.8%, equivalent to approximately 981,000 tons, valued at USD 108 million. Surveys also revealed severe household impacts, limited effectiveness of commonly used insecticides, and greater vulnerability among female farmers in the region.