The honey bee (Apis mellifera) is an essential contributor to crop pollination but has been undergoing population declines in part due to pesticide contaminants in the foraging environment. In particular, honey bees frequently encounter fungicides as they are applied to crop plants during bloom. To assess the effects of the widely used fungicide Pristine® (25.2% boscalid, 12.8% pyraclostrobin) we subjected colonies to doses of the fungicide reflecting levels detected in almond orchards. Chronically exposed hives experienced reduced worker populations and increased winter mortality. We also observed elevated rates of pollen foraging and consumption, potentially indicating impaired protein processing. In this study, we partially tested the hypothesis that Pristine® induced negative effects on protein digestion or absorption, as indexed by hemolymph protein levels. Colonies were continuously fed pollen containing four doses of Pristine® ranging from 0.23 to 230 ppm. Pristine® consumption resulted in lower hemolymph protein levels, and the effect increased with bee age. Chronic Pristine® consumption also induced precocious foraging and reduced longevity. Together, these findings support the hypothesis that fungicides such as Pristine® negatively impact honey bee health at least partly by impairing protein balance. This research was supported by USDA 2017-68004-26322.