ACTIVATION OF THE HYPOPHARYNGEAL GLANDS OF HONEYBEES IN WINTER
E. V. M. BROUWERS
Although the hypopharyngeal glands of overwinrering worker honeybees (Apis mellifera) are hypertrophied, glands isolated from such bees were found to display low rates of protein synthesis ill vitro. In the presence of brood, protein synthesis was activated to a maximum within 3 days; in the absence of brood, however, neither pollen consumption nor juvenile hormone treatment of workers stimulated protein synthesis. When the colony was transferred to a flight room, workers' hypopharyngeal glands remained activated for several weeks while the first brood was being reared. Later, only newly emerged bees were involved in rearing brood.