SummaryThe egg production of 5-frame colonies of honeybees, kept in cages to prevent pollen collection and fed supplemental carbohydrates, bore a direct relationship to the amount of carbohydrate consumed. After 3 days, but not subsequently, the groups fed Beevert or sugar syrup had significantly more brood than those fed with Drivert or Subvert.Other 5-frame experimental colonies, that were allowed free flight and were continuously fed pollen-substitute candy, had more brood at the end of the 33-day test period if they also received carbohydrates than if they did not.Colonies in commercial apiaries reared more brood when they were given either pollen substitute or carbohydrates, or both, than if they received neither. Honey production was also significantly increased by the pollen substitute, but not by the supplemental carbohydrates.