Patterns of larval food production by hypopharyngeal glands in adult worker honey bees

Abstract - Ultrastructural changes of the hypopharyngeal gland cells were analyzed during imaginal development of worker honey bees (Apis mellifera L). The rough endoplasmic reticulum increases immediately after emergence, reaches a maximum during the nursing phase and decreases in field bees. Accordingly, high rates of protein synthesis were measured in nurse bees and low protein production in foragers. Secretion reservoirs are formed within the intracellular ductules. They are surrounded by a sheath of numerous microvilli. Larval food proteins are secreted into the reservoirs and stored as demonstrated immunocytochemically. Even in foraging bees, small amounts of larval food proteins are stored, indicating the flexibility of the worker to potentially react to changing colonial and environmental conditions.