CHARACTERISTICS OF HYPOPHARYNGEAL GLANDS IN HONEYBEES (Apis mellifera carnica) FROM A NURSE COLONY

Abstract

The development and size of hypopharyngeal glands (HPGs) in workers sampled from the nurse colony was compared to workers from the control queen-right honeybee colony. The diameter of the acini in workers (age 1 to 30 days) from the nurse colony ranged from 109.2 to 180.9 μm, and in workers of the same age from the control colony was between 100.8 and 158.2 μm. We found that nurses from the nurse (cell builders) colonies aged 15 to 27 days had significantly larger acinar diameter (p<0.0001) than the workers in the control colonies of the same age. We described the morphological and histological characteristics of the HPGs in nurse workers aged 1 to 27 days and found that HPGs secretion in brood feeding nurses was extended in comparison to workers from the control colony. Moreover, we described the HPGs in a worker pupa before the emergence and in winter bees from the control colony. Results show that HPGs in worker pupae consist of clusters of irregularly shaped secretory acini. Cell cytoplasm is not structured and is homogeneous, nuclei are dense and oval in shape. Winter bees had hypertrophied HPGs and cells containing numerous vesicles accumulating secretion. We found larger acini with a dense structure and milky-white colour. Physiological function of the glands and age related tasks of nurse worker bees is also discussed.