Fine structure of hypopharyngeal glands from honeybees with and without infestation by the tracheal mite, Acarapis woodi (rennie)
T. P. Liu, B. Mobusland G. Braybrook
The hypopharyngeal glands from honeybees, with and without heavy tracheal mite infestation, were examined by electron microscopy. In the healthy bees, the individual saccules of the glands were much larger than those observed in the infested bees. The saccules were round and consisted of numerous acinar cells. The nuclei of the acinar cells were large and rich in euchromatin. The cytoplasm contained well-developed endoplasmic reticulum. Numerous membrane-bound, electron-dense granules, and large masses of less dense membranebound material, was observed in the acinar cells of healthy bees. In the heavily infested bees, the nuclei of the acinar cells contained dispersed euchromatin, and the endoplasmic reticulum had short, dilated cisternae and numerous lysosome bodies were observed. Electron-dense secretory granules were lacking. The secretory materials in the extracellular ducts were much more electron dense than the same materials observed in the healthy honeybees. These changes are interpreted as pathological, degenerative ones, not the consequences of aging.