Osmotic Shock as a Prerequisite to Pollen Digestion in the Alimentary Tract of the Worker Honeybee

SummarySome observations are reported suggesting that, in the worker honeybee, a difference in osmotic pressure between the contents of the honey sac and ventriculus causes pollen grains to burst during their passage through the alimentary tract. Neither gnawing nor enzymatic degradation of the hard pollen wall seems to be necessary for pollen digestion. A similar mechanism may allow Nosema apis to extrude its polar filament in the ventriculus, and thus infect its host.