Brood Rearing by Caged Honey Bees in Response to Inositol and Certain Pollen Fractions in Their Diet1

Abstract

Caged colonies of honey bees, Apis mellifera L., were unable to rear brood beyond a larval age of 3–4 days when fed an artificial diet containing proteins, carbohydrates, lipids, vitamins, and minerals. However, a final concentration of 4.5 mg inositol, a vitamin, in each gram of the artificial food, enabled bees to rear normal brood through the adult stage during a test period of 72 days. Furthermore, addition of 3.5 milligrams of pollen ash per gram of artificial diet also enabled bees to rear all stages of brood during a test period of 44 days. Additions of both pollen ash and inositol to the artificial diet gave no better results than either alone. Bees could rear all stages of brood when a concentrated aqueous extract of crushed pollen grains was mixed with the artificial diet. The concentrate could be prepared either by lyophilization or drying at 100°C in a laboratory oven. No further characterization of the active component(s) in the concentrate has been made. A completely liquid formulation failed to sustain brood rearing. Incorporation of several sterols in addition to cholesterol in artificial diet also failed to sustain brood rearing.