Highlights•Diseases have a central, but poorly understood role in bee foraging
ecology.•Flowers are hubs for horizontal transmission of parasites within and between bee
species.•Nutritional and non-nutritional pollen and nectar chemistry affects bee immunity
and disease.•Diseases modify foraging behaviour by impairing foraging ability or changing
floral preferences.•Parasites affect pollination services by reducing bee populations or
changing foraging behaviour.Diseases have important but understudied effects on bee …