Economic impact assessment and yield loss quantification due to Cimbex quadrimaculata damage in Moroccan almond production

Abstract:

Accurate quantification of pest-induced economic losses is fundamental to the justification of management investments and the prioritization of research allocations in agricultural production systems. This research assessed the economic impact of Cimbex quadrimaculata Müller (Hymenoptera: Cimbicidae) on almond production across four major growing regions of Morocco during the 2020-2025 period. Economic losses were partitioned into three categories: direct yield losses from reduced kernel production, indirect costs associated with pest monitoring and management activities, and quality downgrade losses resulting from damaged kernel classification. Data were collected from 24 commercial orchards encompassing managed and unmanaged production systems. The Beni Mellal-Khénifra region exhibited the highest total economic losses at 2,590 MAD/ha (approximately €240/ha), comprising direct yield losses of 1,560 MAD/ha, indirect management costs of 620 MAD/ha, and quality downgrade losses of 410 MAD/ha. Multi-year yield trend analysis demonstrated progressive yield divergence between managed and unmanaged orchards, with unmanaged production declining from 2.78 to 1.38 kg/tree over the six-year assessment period while managed orchards maintained an upward trajectory from 2.84 to 3.56 kg/tree. Partial budgeting analysis confirmed positive net returns for integrated management in all four regions assessed. These findings provide the first comprehensive economic assessment of C. quadrimaculata impact on Moroccan almond production and establish cost-benefit benchmarks for management decision-making.