CARMA (CAse-based Range Management Adviser) is a system that integrates case-based reasoning with model-based reasoning for rangeland pest management. CARMA’s predictions of rangeland forage loss by grasshoppers were compared to predictions by 15 expert entomologists using either global or case-specific adaptation weights. Under both conditions, CARMA’s predictions were more accurate than CARMA’s case-based and model-based components in isolation. However, CARMA’s case-specific adaptation weights were consistently more accurate than global adaptation weights. The experimental results suggest that case-specific adaptation weights are more appropriate in domains that are poorly approximated by a linear function.